Materiały źródłowe

• #1 Muscular Dystrophy – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560582/

  Muscular dystrophy comprises a group of genetic disorders characterized by progressive muscle weakness and wasting, with a global incidence of approximately 1 in 5,000 individuals. […] The root cause of muscular dystrophy lies in mutations affecting genes responsible for muscle structure and function, leading to the gradual degeneration and loss of muscle fibers. […] Muscular dystrophy can result from mutations in various genes and may be inherited in an X-linked, autosomal dominant, or autosomal recessive manner. […] Changes in the X-linked gene DMD, which encodes dystrophin, are the most frequent cause of muscular dystrophy. […] It is important to note that mutations in dystrophin also create allelic heterogeneity. […] Mutations in the DMD gene, for example, may give rise to either Duchenne or the less severe Becker muscular dystrophy, depending on the extent of the lack of protein.

• #1

  https://www.nhs.uk/conditions/muscular-dystrophy/

  MD is caused by changes (mutations) in the genes responsible for the structure and functioning of a person’s muscles. […] The mutations cause changes in the muscle fibres that interfere with the muscles’ ability to function. Over time, this causes increasing disability. […] The mutations are often inherited from a person’s parents.

• #1 Muscular dystrophy – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/muscular-dystrophy/symptoms-causes/syc-20375388

  Muscular dystrophy occurs when one of these genes is defective. […] Each form of muscular dystrophy is caused by a genetic mutation particular to that type of the disease. Most of these mutations are inherited.

• #1

  https://www.nhs.uk/conditions/muscular-dystrophy/causes/

  In most cases, muscular dystrophy (MD) runs in families. It usually develops after inheriting a faulty gene from one or both parents. […] MD is caused by mutations (alterations) in the genes responsible for healthy muscle structure and function. The mutations mean that the cells that should maintain your muscles can no longer fulfil this role, leading to muscle weakness and progressive disability. […] In a few cases, the genetic mutation that causes MD can also develop as a new event in the family. This is known as a spontaneous mutation. […] Spontaneous gene mutations can occasionally cause MD. This is where the genes mutate for no apparent reason, changing the way the cells function. Spontaneous gene mutations can cause MD to develop in people who don’t have a family history of the condition.

• #1 Muscular Dystrophy: Symptoms, Causes, and More

  https://www.healthline.com/health/muscular-dystrophy

  Muscular dystrophy is a group of conditions that damage and weaken your muscles over time. […] This damage and weakness are due to the lack of a protein called dystrophin, which is necessary for typical muscle function. A deficiency of this protein can cause problems with walking, swallowing, and muscle coordination, among other symptoms. […] Differences in genes cause muscular dystrophy. […] A change in one gene can lead to deficiencies in dystrophin, a critical protein. The body may not make enough dystrophin, may not make it the right way, or may not make it at all. […] People develop muscular dystrophy in one of four ways. The gene differences that cause muscular dystrophy are normally inherited, but they can also come from a spontaneous mutation. […] A person inherits a gene difference from just one parent, on one of the 22 autosomal chromosomes.

• #1 Causes/Inheritance – Duchenne Muscular Dystrophy (DMD) – Diseases | Muscular Dystrophy Association

  https://www.mda.org/disease/duchenne-muscular-dystrophy/causes-inheritance

  Muscles are made up of bundles of fibers (cells). A group of interdependent proteins along the membrane surrounding each fiber helps to keep muscle cells working properly. When one of these proteins, dystrophin, is absent, the result is Duchenne muscular dystrophy (DMD); poor or inadequate dystrophin results in Becker muscular dystrophy (BMD). […] In 1986, MDA-supported researchers identified a gene on the X chromosome that, when flawed (mutated), causes Duchenne, Becker, and an intermediate form of muscular dystrophies. […] DMD occurs because the mutated DMD gene fails to produce virtually any functional dystrophin. […] Many cases of DMD are caused by mutations in the part of the gene that encodes this middle section. Production of the entire protein stops when the mutation is encountered.

• #1 Muscular dystrophy: Symptoms, treatment, types, and causes

  https://www.medicalnewstoday.com/articles/187618

  Genetic changes cause MD. These mutations change how the body produces and maintains healthy muscle tissue. […] Genetic changes cause MD, and each type is due to a different set of mutations. However, all the mutations prevent the body from producing dystrophin, a protein essential for building and repairing muscles. […] Although dystrophin makes up a small percent of the total proteins in muscles, it is an essential molecule for their normal function. It glues various parts of muscle tissue together and links them to the sarcolemma, or the outer membrane. […] If dystrophin is absent or deformed, this process does not work correctly. This weakens the muscles and can damage the muscle cells. […] In DMD, dystrophin is almost entirely absent. Conversely, in BMD, dystrophin is smaller or in short supply.

• #1 Causes/Inheritance – Duchenne Muscular Dystrophy (DMD) – Diseases | Muscular Dystrophy Association

  https://www.mda.org/disease/duchenne-muscular-dystrophy/causes-inheritance

  The absence of dystrophin sets in motion a cascade of harmful effects. […] DMD is inherited in an X-linked pattern because the gene that can carry a DMD-causing mutation is on the X chromosome. […] Each son born to a woman with a dystrophin mutation on one of her two X chromosomes has a 50 percent chance of inheriting the flawed gene and having DMD. […] Although DMD often runs in a family, it is possible for a family with no history of DMD to suddenly have a son with the disease. […] The first is that the genetic mutation leading to DMD may have existed in the females of a family for some generations without anyone knowing. […] A man with DMD cannot pass the flawed gene to his sons because he gives a son a Y chromosome, not an X. […] When a girl inherits a flawed dystrophin gene from one parent, she usually also gets a healthy dystrophin gene from her other parent, giving her enough of the protein to protect her from the disease. […] A minority of females with the mutation, called manifesting carriers, have some signs and symptoms of DMD. […] In very rare instances, a girl may lack a second X chromosome entirely, or her second X may have sustained serious damage.

• #1 Duchenne muscular dystrophy in detail | Duchenne UK

  https://www.duchenneuk.org/duchenne-in-detail/

  Duchenne muscular dystrophy (DMD) is caused by a defect (mutation) in one of the genes in the body. […] Duchenne is caused when very little or no dystrophin is made by the DMD gene because the DMD gene has a defect. […] The genetic defect that causes Duchenne can either be inherited (passed down through the family) or caused by a new change in the DMD gene that occurs in the child. […] This new genetic change is known as a spontaneous mutation and is the cause in more than one third of cases of Duchenne. […] Duchenne is caused by a fault or mutation in the DMD gene. […] There are three different types of changes or mutations in the DMD gene that can cause Duchenne: Deletions of one or more whole exons this is the most common type of mutation and is the cause of around 70% of cases of Duchenne. […] Duplications (additions) of whole exons this type of mutation is the cause of around 10% of cases of Duchenne. […] Other small changes in parts of the genetic code, for example point mutations this type of mutation is the cause of around 20% of cases of Duchenne.

• #1 Myotonic dystrophy type 1 (DM1) – Muscular Dystrophy UK

  https://www.musculardystrophyuk.org/conditions/myotonic-dystrophy/causes

  Myotonic dystrophy type 1 (DM1) is caused by a change in the DMPK gene, which is found on chromosome 19. This change leads to an abnormal increase in a repeated section of genetic code, known as CTG repeats. […] When the CTG repeats get too high, it disrupts how the cells work and causes muscle weakness and other symptoms. Generally, a higher number of repeats means more severe symptoms and an earlier onset. For example, 50 to 100 repeats may cause mild symptoms that appear in adulthood, while thousands of repeats can cause congenital myotonic dystrophy, a severe form of DM1 that is present from birth. […] DM1 is inherited in an autosomal dominant pattern. This means a person needs to inherit the genetic change from one parent for the condition to develop. DM1 often become more severe and appears earlier in each successive generation. This happens because the number of CTG repeats tends to increase when passed from parent to child a phenomenon known as anticipation.

• #1 What causes muscular dystrophy (MD)? | NICHD – Eunice Kennedy Shriver National Institute of Child Health and Human Development

  http://www.nichd.nih.gov/health/topics/musculardys/conditioninfo/causes

  Most cases of MD are caused by gene mutations (changes in the DNA sequence) that affect muscle proteins. […] The mutations are usually inherited, but in some cases they occur spontaneously. These spontaneous mutations can then be inherited by an affected persons offspring. […] There are three different inheritance patterns for most forms of MD. When a mutation that causes MD is inherited by a parent with the condition, this is known as autosomal dominant inheritance. […] However, the inheritance pattern for many types of MD is called X-linked recessive, meaning that the genetic change is passed from one generation to the next through the X chromosome. […] Hundreds of genes are involved in making proteins that affect muscles. Each form of MD is caused by a genetic mutation that is unique to that type.

• #1 Patient education: Overview of muscular dystrophies (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/overview-of-muscular-dystrophies-beyond-the-basics/print

  Muscular dystrophy is an inherited disorder that causes progressive muscle weakness (myopathy) and atrophy (loss of muscle mass) due to defects in one or more genes required for normal muscle function. Some of the genes responsible for these conditions have been identified. […] The genetic defect that causes muscular dystrophy is passed from one or both parents to a child by a specific pattern of inheritance that varies from one type of muscular dystrophy to another. […] Duchenne and Becker muscular dystrophy and one type of Emery-Dreifuss muscular dystrophy (EDMD) are caused by mutations (also called „pathogenic variants”) on one of the X chromosomes carried by the female parent. These muscular dystrophies affect 50 percent of male infants of mothers who carry the genetic defect; this is called X-linked recessive inheritance.

• #1 About Duchenne Muscular Dystrophy

  https://www.genome.gov/Genetic-Disorders/Duchenne-Muscular-Dystrophy

  Duchenne muscular dystrophy (DMD) is a rapidly progressive form of muscular dystrophy caused by a mutation in the DMD gene. […] It is caused by an alteration (mutation) in a gene, called the DMD gene that can be inherited in families in an X-linked recessive fashion, but it often occurs in people from families without a known family history of the condition. […] Duchenne muscular dystrophy is inherited in an X-linked recessive pattern. Males have only one copy of the X chromosome from their mother and one copy of the Y chromosome from their father. If their X chromosome has a DMD gene mutation, they will have Duchenne muscular dystrophy. […] A woman who has a genetic change in one of her two copies is said to be „a carrier” of Duchenne muscular dystrophy. […] However, recent studies have shown that some carrier females (approximately 20 percent) will show symptoms of DMD, including muscle weakness and cardiac abnormalities. […] The chance of a woman who has one affected son (and no family history) of being a carrier of the changed DMD gene is approximately 2/3. […] Males who inherit or are born with a changed copy of the DMD gene will have DMD since they have a Y chromosome, and do not have back-up X chromosome.

• #1 Muscular Dystrophy: What It Is, Symptoms, Types & Treatment

  https://my.clevelandclinic.org/health/diseases/14128-muscular-dystrophy

  Sex-linked (X-linked) inheritance: A genetically male person has one X and one Y chromosome, and a genetically female person has two X chromosomes. A genetic mutation on the X chromosome causes a sex-linked condition. […] In rare cases, a person may develop muscular dystrophy spontaneously, meaning the mutation happened randomly and wasn’t inherited. This is called a de novo mutation.

• #1 Patient education: Overview of muscular dystrophies (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/overview-of-muscular-dystrophies-beyond-the-basics/print

  Myotonic muscular dystrophy, facioscapulohumeral muscular dystrophy (FSHD), some types of congenital muscular dystrophy (CMD), one type of EDMD, and some types of limb-girdle muscular dystrophy (LGMD) can develop if either of the parent’s chromosomes carries the defect and is passed to the infant; this is called autosomal dominant inheritance. […] Most types of CMD, one rare type of EDMD, and some types of LGMD develop if both parents pass a defective chromosome to their infant; this is called autosomal recessive inheritance.

• #1 Muscular Dystrophy: What It Is, Symptoms, Types & Treatment

  https://my.clevelandclinic.org/health/diseases/14128-muscular-dystrophy

  Muscular dystrophy refers to a group of more than 30 genetic conditions that cause muscle weakness and other muscle-related symptoms. […] Mutations (changes) in the genes that are responsible for healthy muscle structure and function cause muscular dystrophy. The mutations mean that the cells that would normally maintain your muscles can no longer fulfill this role, leading to progressive muscle weakness. […] In the majority of muscular dystrophy cases, you inherit the genetic mutation from one or both of your biological parents. […] There are three ways you can inherit muscular dystrophy, depending on the specific type: Recessive inheritance: This means you’ve inherited a genetic mutation that causes the condition from both of your biological parents. […] Dominant inheritance: This means you only need to inherit the mutated gene from one of your biological parents to develop the condition.

• #1 Muscular dystrophy | Better Health Channel

  https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/muscular-dystrophy

  Muscular dystrophies are inherited muscle conditions. […] Muscular dystrophy occurs if one of these genes does not work properly. Each type of muscular dystrophy is caused by a different change in a gene. Some of these gene changes are inherited from a parent. Some of them are new changes that occur early in development. These are known as spontaneous or de novo gene changes. […] The congenital muscular dystrophies (CMDs) are a group of conditions that vary in severity and rates of progression. […] In most cases of congenital muscular dystrophy, the initial symptoms are present at birth or in the first few months. […] There are at least five different types of CMD, which are caused by variations in different genes. Both parents usually carry the altered gene but are unaffected by the condition. The affected child inherits two copies of the altered gene one from each parent.

• #1 Muscular Dystrophy: Symptoms, Causes, and More

  https://www.healthline.com/health/muscular-dystrophy

  A person inherits a gene difference from both parents, on one of the 22 autosomal chromosomes. […] This inheritance is connected to the genes linked to the X chromosome. […] In this case, muscular dystrophy develops because of a spontaneous change in genes. It occurs in people whose biological parents were not carriers of the gene difference.

• #1 Genetic Causes – Parent Project Muscular Dystrophy

  https://www.parentprojectmd.org/about-duchenne/what-is-duchenne/genetic-causes/

  Duchenne muscular dystrophy is caused by changes in a single gene in our body. Duchenne can be passed from parent to child, or it can be the result of random spontaneous genetic mutations, which may occur during any pregnancy. In fact, about one out of every three cases occurs in families with no previous history of Duchenne. […] Duchenne muscular dystrophy is caused by a change in the dystrophin gene. […] Changes to the gene, called mutations, can lead to differences in the amount or size of the dystrophin protein. Duchenne occurs because there is not enough dystrophin protein in the muscle cells or the dystrophin protein present does not work correctly. […] Duchenne can also occur without being passed from parent to child, as the result of random spontaneous genetic mutations, which may occur during any pregnancy. About 1 out of every 3 cases occurs in families with no previous history of Duchenne.

• #1 Muscular dystrophy (MD) | NHS inform

  https://www.nhsinform.scot/illnesses-and-conditions/brain-nerves-and-spinal-cord/muscular-dystrophy/muscular-dystrophy/

  Muscular dystrophy usually develops because a faulty gene has been inherited from one or both parents. It normally runs in families. […] MD is caused by mutations (changes) in the genes responsible for healthy muscle structure and function. This leads to muscle weakness and can eventually result in disability. […] A gene mutation is like a spelling mistake within the gene code. This can lead to a change in the protein expression in the muscle causing structural changes and damage in the muscle. […] Depending on the type of MD the condition could be a: recessive inherited disorder, dominant inherited disorder, sex linked (X-linked) disorder. […] In rare cases, the genetic mutation can develop as a new event in the family (spontaneous mutation). […] Sometimes, spontaneous gene mutations can cause MD. This happens when the gene mutates for no apparent reason, changing the way the cells operate. […] If a person with MD has no family history of the condition, it might be caused by a spontaneous gene mutation.

• #1 Muscular Dystrophy – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560582/

  Muscular dystrophy most often results from defective or absent glycoproteins in the muscle membrane. […] Various types of muscular dystrophy are associated with distinct gene deletions or mutations, giving rise to diverse enzymatic or metabolic defects. […] While the genetic mutations causing muscular dystrophy may differ, the underlying mechanism of muscle degeneration and loss remains similar across all types of the disease. […] Although the phenotypic characteristics of certain muscular dystrophies are well-defined, the spectrum produced by mutations in various genes overlap, leading to nonallelic heterogeneity. […] Recognizing nonallelic heterogeneity is crucial for several reasons. […] Phenocopies can arise when nongenetic diseases simulate the symptoms of a genetic disorder. […] It is important to note that muscular dystrophy exhibits variable expressivity and incomplete penetrance, contributing to its manifestations across a phenotypic spectrum in different affected individuals, highlighting the concept of variable expressivity.

• #1 Duchenne and Becker muscular dystrophy: MedlinePlus GeneticsLock

  https://medlineplus.gov/genetics/condition/duchenne-and-becker-muscular-dystrophy/

  Muscular dystrophies are a group of genetic conditions characterized by progressive muscle weakness and wasting (atrophy). […] Duchenne and Becker muscular dystrophies have similar signs and symptoms and are caused by different mutations in the same gene. […] Mutations in the DMD gene cause the Duchenne and Becker forms of muscular dystrophy. […] Mutations in the DMD gene alter the structure or function of dystrophin or prevent any functional dystrophin from being produced. […] Because Duchenne and Becker muscular dystrophies result from faulty or missing dystrophin, these conditions are classified as dystrophinopathies.

• #1 Muscular Dystrophy: Practice Essentials, Pathophysiology, Etiology

  https://emedicine.medscape.com/article/1259041-overview

  The etiology of MD is an abnormality in the genetic code for specific muscle proteins. […] In the X-linked forms of MD, such as the Duchenne and Becker dystrophies, the defect is located on the short arm of the X chromosome. […] The gene codes for Dp427, which is a component of the cytoskeleton of the cell membrane. […] Defects that interfere with the translation reading frame or with the promoter sequence that initiates synthesis of dystrophin lead to an unstable, ineffective protein, as in Duchenne MD. […] In autosomal recessive conditions such as limb-girdle MD, the genetic defect is localized to the 13q12 locus. […] In the autosomal dominant facioscapulohumeral MD, the defect is at the 4q35 locus.

• #1 Causes of DMD | Muscular Dystrophy NewsEnvelope icon

  https://musculardystrophynews.com/duchenne-muscular-dystrophy-causes/

  Duchenne muscular dystrophy (DMD) is a progressive muscle wasting condition that mainly affects skeletal and heart muscles. […] DMD is caused by a mutation in the DMD gene, which encodes for a protein called dystrophin. […] The most common DMD-causing mutation is the deletion of a large section of the DMD gene. […] Another common mutation seen in DMD patients is a “nonsense mutation.”

• #1 Patient education: Overview of muscular dystrophies (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/overview-of-muscular-dystrophies-beyond-the-basics

  Most types of CMD, one rare type of EDMD, and some types of LGMD develop if both parents pass a defective chromosome to their infant; this is called autosomal recessive inheritance. […] Many things can cause myopathy to occur, a few of which include: Inherited conditions, particularly muscular dystrophies. […] Duchenne muscular dystrophy (DMD) is caused by a defect in the DMD gene located on the X chromosome. This gene is responsible for producing a protein called dystrophin, which normally functions to protect muscle fibers. […] Becker muscular dystrophy (BMD) is also caused by problems with the dystrophin gene, although people with BMD often have partial production of dystrophin. […] Some patients are found to have the genetic abnormalities of the dystrophin gene, but, clinically, have symptoms between those of Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD).

• #1 Becker muscular dystrophy (BMD) – Muscular Dystrophy UK

  https://www.musculardystrophyuk.org/conditions/a-z/becker-muscular-dystrophy/

  BMD is caused by a change in the dystrophin gene. The dystrophin gene provides instructions to make the dystrophin protein. This protein maintains the structure of the muscles. In people with BMD, the body makes some dystrophin, but not enough. This causes muscles to weaken over time because muscle fibres break down. […] Duchenne muscular dystrophy (DMD) is a more severe condition caused by a complete lack of dystrophin. DMD usually begins in early childhood and progresses quickly, leading to loss of mobility and serious health problems. In comparison, BMD is generally milder, because the body still makes some dystrophin, so it’s not associated with the severe complications seen in DMD. […] BMD is inherited in an X-linked recessive pattern. This means the genetic change causing BMD is located on the X chromosome. Males have only one X chromosome, so they are more likely to be affected by BMD. Females have two X chromosomes, so they are less likely to develop symptoms.

• #1 Myotonic dystrophy – Wikipedia

  https://en.wikipedia.org/wiki/Myotonic_dystrophy

  Myotonic dystrophy is caused by a genetic mutation in one of two genes. Mutation of the DMPK gene causes myotonic dystrophy type 1 (DM1). Mutation of CNBP gene causes type 2 (DM2). […] DM is typically inherited, following an autosomal dominant inheritance pattern, and it generally worsens with each generation. […] The microsatellite expansion responsible for DM1 is of cytosine-thymine-guanine (CTG) triplet repeats, termed trinucleotide repeat expansion and classifying DM1 as one of several trinucleotide repeat disorders. […] The repeat expansion for DM2 is much larger than for DM1, ranging from 75 to over 11,000 repeats. […] Myotonic dystrophy is inherited in an autosomal dominant pattern.

• #1 Causes | Muscular Dystrophy NewsEnvelope icon

  https://musculardystrophynews.com/causes/

  Muscular dystrophies are caused by mutations in genes that are important for muscle health. These mutations may be inherited — passed from parents to their biological children — or they can occur de novo (spontaneously) in an individual. […] There are more than 30 different types of muscular dystrophy, each of which is caused by mutations in particular genes. […] The two most common types of muscular dystrophy, Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD), both are caused by mutations in the DMD gene. […] Facioscapulohumeral muscular dystrophy (FSHD) is caused by alterations in the D4Z4 region, which is a section of DNA located at the end of chromosome 4. […] Limb-girdle muscular dystrophy (LGMD) mainly affects muscles in the shoulders and hips. There are several types of LGMD caused by mutations in different genes that are important for muscle health, including LMNA, CAV3, CAPN3, and DYSF.

• #1

  https://exonpublications.com/index.php/exon/article/view/muscular-dystrophy-patient-education

  Facioscapulohumeral Muscular Dystrophy (FSHD): Associated with genetic changes near the end of chromosome 4, particularly a deletion in the D4Z4 region affecting the regulation of the DUX4 gene, leading to muscle cell damage. […] Emery-Dreifuss Muscular Dystrophy: Typically linked to mutations in the EMD and LMNA genes, which affect proteins essential for the structural health of the cell nucleus, compromising muscle cell stability and function. […] Distal Muscular Dystrophy: Involves mutations in genes like DYSF, GNE, and MYOT, essential for normal muscle function, affecting the distal parts of the limbs. […] Oculopharyngeal Muscular Dystrophy (OPMD): Caused by an abnormal expansion in the PABPN1 gene, leading to the production of an abnormal protein that disrupts muscle cell function, particularly in the eyelids and throat. […] Collagen Type VI-Related Disorders: Such as Ullrich congenital muscular dystrophy and Bethlem myopathy, are caused by mutations in the COL6A1, COL6A2, and COL6A3 genes, critical for producing collagen VI, a key component of connective tissues.

• #1 Muscular Dystrophy – symptoms, stages, meaning, Definition, Description, Demographics, Causes and symptoms

  http://www.healthofchildren.com/M/Muscular-Dystrophy.html

  Muscular dystrophy is the name for a group of inherited disorders in which strength and muscle bulk gradually decline. […] Several of the muscular dystrophies, including DMD, BMD, CMD, and most forms of LGMD, are due to defects in the genes for a complex of muscle proteins. […] Both DMD and BMD are caused by flaws in the gene for the protein called dystrophin. […] The causes of the other muscular dystrophies are not as well understood: […] One form of LGMD is caused by defects in the gene for a muscle enzyme, calpain. […] EDMD is due to a defect in the gene for a protein called emerin, which is found in the membrane of a cell’s nucleus, but whose exact function is unknown. […] Myotonic dystrophy is linked to gene defects for a protein that may control the flow of charged particles within muscle cells. […] The gene for OPMD appears to also be mutated with a triple repeat. […] The cause of FSH is unknown. […] The gene responsible for DD has not yet been found.

• #1 Causes/Inheritance – Congenital Muscular Dystrophy (CMD) – Diseases | Muscular Dystrophy Association

  https://www.mda.org/disease/congenital-muscular-dystrophy/causes-inheritance

  Muscle cells are embedded in a web-like structure known as the extracellular matrix (ECM). Many CMDs are due to mutations in glycoproteins themselves, or in the enzymes that create them. One group of CMDs are due to mutations in genes that help glycosylate (add sugar molecules to) the protein alpha-dystroglycan, a key glycoprotein of the ECM. […] Loss of glycoproteins due to mutation interferes with normal muscle function. A consequence of most CMD-causing mutations is increased susceptibility to cellular injury from normal contraction, and/or a reduction in the ability to repair damage. […] In the mid-1990s, researchers found that a deficiency of a protein then called merosin and now more often called laminin 211 was the underlying cause of at least some cases of CMD. […] As the 20th century ended, researchers began to suspect that Ullrichs disease, now known as Ullrich CMD, was caused by a lack of collagen 6, a ropelike protein located in the area where laminin 211 is found.

• #1 DUCHENNE MUSCULAR DYSTROPHY: EXPLORING CAUSES, SYMPTOMS, AND RECENT BREAKTHROUGH RESEARCH | Mya Care

  https://myacare.com/blog/duchenne-muscular-dystrophy-exploring-causes-symptoms-and-recent-breakthrough-research

  Duchenne Muscular Dystrophy (DMD) is a rare recessive genetic neuromuscular disease that causes the slow degeneration of muscle fibers and progressive limb weakness. The condition results from genetic mutations in the DMD gene, which prevents the production of dystrophin, a vital protein required to keep muscle cell membranes intact. DMD is the most severe form of disease within the spectrum of inherited muscular dystrophies, all of which arise due to dystrophin gene mutations. […] The cause of DMD is a mutation in the DMD gene, which is a gene that codes for dystrophin and is located on chromosome X (or Xp21). […] Dystrophin is a protein that helps keep muscle cells intact and stable by connecting muscle filaments inside muscle cells to the cell wall. This reinforces the muscles structure and ability to contract. It also helps to transmit the force generated by contracting muscle to the tendon and bone. Without dystrophin, both muscle and bone become more vulnerable to damage and degeneration.

• #1 What causes muscular dystrophy? :: CSHL DNA Learning Center

  https://dnalc.cshl.edu/view/15958-What-causes-muscular-dystrophy-.html

  The DMD gene codes for a large protein called dystrophin that is necessary for muscle cells to maintain their shape. When this protein is missing, muscle cells literally explode as material from outside the cell walls leaks in raising cell pressure. Mutations in the DMD gene can cause a muscle-wasting disorder, called Duchenne muscular dystrophy, or its milder form, Becker muscular dystrophy. […] The DMD gene codes for a large protein called dystrophin that is necessary for muscle cells to maintain their shape. […] The DMD gene codes for a large protein called dystrophin that is necessary for muscle cells to maintain their shape.

• #1 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Muscular-Dystrophy-Causes.aspx

  It has been demonstrated that most muscular dystrophies share some common pathologic features, such as altered homeostasis of calcium ions, an increase in profibrotic cytokines, proteolytic enzyme activation, infiltration of muscle tissue by inflammatory cells of the immune system, metabolic and mitochondrial alterations, defective autophagy, and intracellular accumulation of reactive oxygen species (ROS). […] Each of these features can contribute to muscle wasting.

• #1

  https://continentalhospitals.com/diseases/muscular-dystrophy/

  These genetic abnormalities disrupt the normal processes within muscle cells, eventually resulting in muscle wasting and loss of strength. While understanding the genetic causes of muscular dystrophy is crucial, it is also important to note that environmental factors can influence disease progression. Factors such as diet, exercise, and exposure to toxins may interact with genetic predispositions and impact the severity and progression of symptoms. […] By delving into the causes of muscular dystrophy, researchers can gain valuable insights into potential treatment options and interventions. Additionally, understanding these causes allows for improved genetic counseling services for families at risk or already affected by this condition.

• #1 What causes muscular dystrophy (MD)? | NICHD – Eunice Kennedy Shriver National Institute of Child Health and Human Development

  http://www.nichd.nih.gov/health/topics/musculardys/conditioninfo/causes

  Duchenne MD results from a genetic mutation that leads to a lack of dystrophin, a protein that helps strengthen muscle fibers and protect them from injury. […] Myotonic MD is caused by an abnormal expansion of certain DNA sequences on one of two different genes. […] MD is not contagious and cannot be caused by injury or activity.

• #1 What Is Muscular Dystrophy? Symptoms, Causes, Diagnosis, Treatment, and More

  https://www.everydayhealth.com/genetic-diseases/muscular-dystrophy/

  Muscular dystrophy is caused by genetic variations that interfere with the production of proteins needed to build and maintain healthy muscles. […] The most common forms of muscular dystrophy are caused by a variation on the X chromosome influencing production of a protein called dystrophin, while other types of muscular dystrophy have their own set of unique genetic variations, affecting the production of other proteins. […] In most cases, the genetic variations that cause muscular dystrophy run in families and are passed from parents to children. […] However, for some types of muscular dystrophy, you have to inherit two copies of a nonworking gene, one from each parent, to have the disease; this is called an autosomal recessive inherited disorder. […] For other types of muscular dystrophy, you need only inherit one copy of a nonworking gene from one parent to have the disease; this is called a dominant inherited disorder.

• #2 Muscular Dystrophy – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560582/

  Muscular dystrophy comprises a group of genetic disorders characterized by progressive muscle weakness and wasting, with a global incidence of approximately 1 in 5,000 individuals. […] The root cause of muscular dystrophy lies in mutations affecting genes responsible for muscle structure and function, leading to the gradual degeneration and loss of muscle fibers. […] Muscular dystrophy can result from mutations in various genes and may be inherited in an X-linked, autosomal dominant, or autosomal recessive manner. […] Changes in the X-linked gene DMD, which encodes dystrophin, are the most frequent cause of muscular dystrophy. […] It is important to note that mutations in dystrophin also create allelic heterogeneity. […] Mutations in the DMD gene, for example, may give rise to either Duchenne or the less severe Becker muscular dystrophy, depending on the extent of the lack of protein.

• #2

  https://www.nhs.uk/conditions/muscular-dystrophy/

  MD is caused by changes (mutations) in the genes responsible for the structure and functioning of a person’s muscles. […] The mutations cause changes in the muscle fibres that interfere with the muscles’ ability to function. Over time, this causes increasing disability. […] The mutations are often inherited from a person’s parents.

• #2 What causes muscular dystrophy (MD)? | NICHD – Eunice Kennedy Shriver National Institute of Child Health and Human Development

  http://www.nichd.nih.gov/health/topics/musculardys/conditioninfo/causes

  Most cases of MD are caused by gene mutations (changes in the DNA sequence) that affect muscle proteins. […] The mutations are usually inherited, but in some cases they occur spontaneously. These spontaneous mutations can then be inherited by an affected persons offspring. […] There are three different inheritance patterns for most forms of MD. When a mutation that causes MD is inherited by a parent with the condition, this is known as autosomal dominant inheritance. […] However, the inheritance pattern for many types of MD is called X-linked recessive, meaning that the genetic change is passed from one generation to the next through the X chromosome. […] Hundreds of genes are involved in making proteins that affect muscles. Each form of MD is caused by a genetic mutation that is unique to that type.

• #2 Muscular Dystrophy: Symptoms, Causes, and More

  https://www.healthline.com/health/muscular-dystrophy

  Muscular dystrophy is a group of conditions that damage and weaken your muscles over time. […] This damage and weakness are due to the lack of a protein called dystrophin, which is necessary for typical muscle function. A deficiency of this protein can cause problems with walking, swallowing, and muscle coordination, among other symptoms. […] Differences in genes cause muscular dystrophy. […] A change in one gene can lead to deficiencies in dystrophin, a critical protein. The body may not make enough dystrophin, may not make it the right way, or may not make it at all. […] People develop muscular dystrophy in one of four ways. The gene differences that cause muscular dystrophy are normally inherited, but they can also come from a spontaneous mutation. […] A person inherits a gene difference from just one parent, on one of the 22 autosomal chromosomes.

• #2 Duchenne muscular dystrophy in detail | Duchenne UK

  https://www.duchenneuk.org/duchenne-in-detail/

  Duchenne muscular dystrophy (DMD) is caused by a defect (mutation) in one of the genes in the body. […] Duchenne is caused when very little or no dystrophin is made by the DMD gene because the DMD gene has a defect. […] The genetic defect that causes Duchenne can either be inherited (passed down through the family) or caused by a new change in the DMD gene that occurs in the child. […] This new genetic change is known as a spontaneous mutation and is the cause in more than one third of cases of Duchenne. […] Duchenne is caused by a fault or mutation in the DMD gene. […] There are three different types of changes or mutations in the DMD gene that can cause Duchenne: Deletions of one or more whole exons this is the most common type of mutation and is the cause of around 70% of cases of Duchenne. […] Duplications (additions) of whole exons this type of mutation is the cause of around 10% of cases of Duchenne. […] Other small changes in parts of the genetic code, for example point mutations this type of mutation is the cause of around 20% of cases of Duchenne.

• #2 Patient education: Overview of muscular dystrophies (Beyond the Basics) – UpToDate

  https://www.uptodate.com/contents/overview-of-muscular-dystrophies-beyond-the-basics/print

  Muscular dystrophy is an inherited disorder that causes progressive muscle weakness (myopathy) and atrophy (loss of muscle mass) due to defects in one or more genes required for normal muscle function. Some of the genes responsible for these conditions have been identified. […] The genetic defect that causes muscular dystrophy is passed from one or both parents to a child by a specific pattern of inheritance that varies from one type of muscular dystrophy to another. […] Duchenne and Becker muscular dystrophy and one type of Emery-Dreifuss muscular dystrophy (EDMD) are caused by mutations (also called „pathogenic variants”) on one of the X chromosomes carried by the female parent. These muscular dystrophies affect 50 percent of male infants of mothers who carry the genetic defect; this is called X-linked recessive inheritance.

• #2 Causes/Inheritance – Congenital Muscular Dystrophy (CMD) – Diseases | Muscular Dystrophy Association

  https://www.mda.org/disease/congenital-muscular-dystrophy/causes-inheritance

  Many forms of congenital muscular dystrophy stem from loss of firm connections between muscle fibers and their surroundings (extracellular matrix). […] The CMDs are caused by genetic defects that affect important muscle proteins. Most forms of CMD are inherited in an autosomal recessive pattern. […] If a disease is recessive, two copies of the defective gene (one from each parent) are required to produce the disease. […] If a disease is dominant, then only one copy of the genetic defect is needed to cause the disease.

• #2 Causes of DMD | Muscular Dystrophy NewsEnvelope icon

  https://musculardystrophynews.com/duchenne-muscular-dystrophy-causes/

  Duchenne muscular dystrophy (DMD) is a progressive muscle wasting condition that mainly affects skeletal and heart muscles. […] DMD is caused by a mutation in the DMD gene, which encodes for a protein called dystrophin. […] The most common DMD-causing mutation is the deletion of a large section of the DMD gene. […] Another common mutation seen in DMD patients is a “nonsense mutation.”

• #2 Myotonic dystrophy type 1 (DM1) – Muscular Dystrophy UK

  https://www.musculardystrophyuk.org/conditions/myotonic-dystrophy/causes

  Myotonic dystrophy type 1 (DM1) is caused by a change in the DMPK gene, which is found on chromosome 19. This change leads to an abnormal increase in a repeated section of genetic code, known as CTG repeats. […] When the CTG repeats get too high, it disrupts how the cells work and causes muscle weakness and other symptoms. Generally, a higher number of repeats means more severe symptoms and an earlier onset. For example, 50 to 100 repeats may cause mild symptoms that appear in adulthood, while thousands of repeats can cause congenital myotonic dystrophy, a severe form of DM1 that is present from birth. […] DM1 is inherited in an autosomal dominant pattern. This means a person needs to inherit the genetic change from one parent for the condition to develop. DM1 often become more severe and appears earlier in each successive generation. This happens because the number of CTG repeats tends to increase when passed from parent to child a phenomenon known as anticipation.

• #2 Myotonic dystrophy – Wikipedia

  https://en.wikipedia.org/wiki/Myotonic_dystrophy

  Myotonic dystrophy is caused by a genetic mutation in one of two genes. Mutation of the DMPK gene causes myotonic dystrophy type 1 (DM1). Mutation of CNBP gene causes type 2 (DM2). […] DM is typically inherited, following an autosomal dominant inheritance pattern, and it generally worsens with each generation. […] The microsatellite expansion responsible for DM1 is of cytosine-thymine-guanine (CTG) triplet repeats, termed trinucleotide repeat expansion and classifying DM1 as one of several trinucleotide repeat disorders. […] The repeat expansion for DM2 is much larger than for DM1, ranging from 75 to over 11,000 repeats. […] Myotonic dystrophy is inherited in an autosomal dominant pattern.

• #2 Causes | Muscular Dystrophy NewsEnvelope icon

  https://musculardystrophynews.com/causes/

  Muscular dystrophies are caused by mutations in genes that are important for muscle health. These mutations may be inherited — passed from parents to their biological children — or they can occur de novo (spontaneously) in an individual. […] There are more than 30 different types of muscular dystrophy, each of which is caused by mutations in particular genes. […] The two most common types of muscular dystrophy, Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD), both are caused by mutations in the DMD gene. […] Facioscapulohumeral muscular dystrophy (FSHD) is caused by alterations in the D4Z4 region, which is a section of DNA located at the end of chromosome 4. […] Limb-girdle muscular dystrophy (LGMD) mainly affects muscles in the shoulders and hips. There are several types of LGMD caused by mutations in different genes that are important for muscle health, including LMNA, CAV3, CAPN3, and DYSF.

• #2 Causes/Inheritance – Congenital Muscular Dystrophy (CMD) – Diseases | Muscular Dystrophy Association

  https://www.mda.org/disease/congenital-muscular-dystrophy/causes-inheritance

  Muscle cells are embedded in a web-like structure known as the extracellular matrix (ECM). Many CMDs are due to mutations in glycoproteins themselves, or in the enzymes that create them. One group of CMDs are due to mutations in genes that help glycosylate (add sugar molecules to) the protein alpha-dystroglycan, a key glycoprotein of the ECM. […] Loss of glycoproteins due to mutation interferes with normal muscle function. A consequence of most CMD-causing mutations is increased susceptibility to cellular injury from normal contraction, and/or a reduction in the ability to repair damage. […] In the mid-1990s, researchers found that a deficiency of a protein then called merosin and now more often called laminin 211 was the underlying cause of at least some cases of CMD. […] As the 20th century ended, researchers began to suspect that Ullrichs disease, now known as Ullrich CMD, was caused by a lack of collagen 6, a ropelike protein located in the area where laminin 211 is found.

• #2 DUCHENNE MUSCULAR DYSTROPHY: EXPLORING CAUSES, SYMPTOMS, AND RECENT BREAKTHROUGH RESEARCH | Mya Care

  https://myacare.com/blog/duchenne-muscular-dystrophy-exploring-causes-symptoms-and-recent-breakthrough-research

  Duchenne Muscular Dystrophy (DMD) is a rare recessive genetic neuromuscular disease that causes the slow degeneration of muscle fibers and progressive limb weakness. The condition results from genetic mutations in the DMD gene, which prevents the production of dystrophin, a vital protein required to keep muscle cell membranes intact. DMD is the most severe form of disease within the spectrum of inherited muscular dystrophies, all of which arise due to dystrophin gene mutations. […] The cause of DMD is a mutation in the DMD gene, which is a gene that codes for dystrophin and is located on chromosome X (or Xp21). […] Dystrophin is a protein that helps keep muscle cells intact and stable by connecting muscle filaments inside muscle cells to the cell wall. This reinforces the muscles structure and ability to contract. It also helps to transmit the force generated by contracting muscle to the tendon and bone. Without dystrophin, both muscle and bone become more vulnerable to damage and degeneration.

• #2 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Muscular-Dystrophy-Causes.aspx

  It has been demonstrated that most muscular dystrophies share some common pathologic features, such as altered homeostasis of calcium ions, an increase in profibrotic cytokines, proteolytic enzyme activation, infiltration of muscle tissue by inflammatory cells of the immune system, metabolic and mitochondrial alterations, defective autophagy, and intracellular accumulation of reactive oxygen species (ROS). […] Each of these features can contribute to muscle wasting.

• #2 Muscular Dystrophy – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560582/

  Muscular dystrophy most often results from defective or absent glycoproteins in the muscle membrane. […] Various types of muscular dystrophy are associated with distinct gene deletions or mutations, giving rise to diverse enzymatic or metabolic defects. […] While the genetic mutations causing muscular dystrophy may differ, the underlying mechanism of muscle degeneration and loss remains similar across all types of the disease. […] Although the phenotypic characteristics of certain muscular dystrophies are well-defined, the spectrum produced by mutations in various genes overlap, leading to nonallelic heterogeneity. […] Recognizing nonallelic heterogeneity is crucial for several reasons. […] Phenocopies can arise when nongenetic diseases simulate the symptoms of a genetic disorder. […] It is important to note that muscular dystrophy exhibits variable expressivity and incomplete penetrance, contributing to its manifestations across a phenotypic spectrum in different affected individuals, highlighting the concept of variable expressivity.

• #2

  https://continentalhospitals.com/diseases/muscular-dystrophy/

  These genetic abnormalities disrupt the normal processes within muscle cells, eventually resulting in muscle wasting and loss of strength. While understanding the genetic causes of muscular dystrophy is crucial, it is also important to note that environmental factors can influence disease progression. Factors such as diet, exercise, and exposure to toxins may interact with genetic predispositions and impact the severity and progression of symptoms. […] By delving into the causes of muscular dystrophy, researchers can gain valuable insights into potential treatment options and interventions. Additionally, understanding these causes allows for improved genetic counseling services for families at risk or already affected by this condition.

• #2 What Is Muscular Dystrophy? Symptoms, Causes, Diagnosis, Treatment, and More

  https://www.everydayhealth.com/genetic-diseases/muscular-dystrophy/

  Muscular dystrophy is caused by genetic variations that interfere with the production of proteins needed to build and maintain healthy muscles. […] The most common forms of muscular dystrophy are caused by a variation on the X chromosome influencing production of a protein called dystrophin, while other types of muscular dystrophy have their own set of unique genetic variations, affecting the production of other proteins. […] In most cases, the genetic variations that cause muscular dystrophy run in families and are passed from parents to children. […] However, for some types of muscular dystrophy, you have to inherit two copies of a nonworking gene, one from each parent, to have the disease; this is called an autosomal recessive inherited disorder. […] For other types of muscular dystrophy, you need only inherit one copy of a nonworking gene from one parent to have the disease; this is called a dominant inherited disorder.

• #3 Muscular dystrophy – Wikipedia

  https://en.wikipedia.org/wiki/Muscular_dystrophy

  Muscular dystrophies are caused by mutations in genes, usually those involved in making muscle proteins. […] These mutations are either inherited from parents or may occur spontaneously during early development. […] The majority of muscular dystrophies are inherited; the different muscular dystrophies follow various inheritance patterns (X-linked, autosomal recessive or autosomal dominant).

• #3 What causes muscular dystrophy (MD)? | NICHD – Eunice Kennedy Shriver National Institute of Child Health and Human Development

  http://www.nichd.nih.gov/health/topics/musculardys/conditioninfo/causes

  Most cases of MD are caused by gene mutations (changes in the DNA sequence) that affect muscle proteins. […] The mutations are usually inherited, but in some cases they occur spontaneously. These spontaneous mutations can then be inherited by an affected persons offspring. […] There are three different inheritance patterns for most forms of MD. When a mutation that causes MD is inherited by a parent with the condition, this is known as autosomal dominant inheritance. […] However, the inheritance pattern for many types of MD is called X-linked recessive, meaning that the genetic change is passed from one generation to the next through the X chromosome. […] Hundreds of genes are involved in making proteins that affect muscles. Each form of MD is caused by a genetic mutation that is unique to that type.

• #3 Muscular Dystrophy – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560582/

  Muscular dystrophy comprises a group of genetic disorders characterized by progressive muscle weakness and wasting, with a global incidence of approximately 1 in 5,000 individuals. […] The root cause of muscular dystrophy lies in mutations affecting genes responsible for muscle structure and function, leading to the gradual degeneration and loss of muscle fibers. […] Muscular dystrophy can result from mutations in various genes and may be inherited in an X-linked, autosomal dominant, or autosomal recessive manner. […] Changes in the X-linked gene DMD, which encodes dystrophin, are the most frequent cause of muscular dystrophy. […] It is important to note that mutations in dystrophin also create allelic heterogeneity. […] Mutations in the DMD gene, for example, may give rise to either Duchenne or the less severe Becker muscular dystrophy, depending on the extent of the lack of protein.

• #3 Duchenne muscular dystrophy in detail | Duchenne UK

  https://www.duchenneuk.org/duchenne-in-detail/

  Duchenne muscular dystrophy (DMD) is caused by a defect (mutation) in one of the genes in the body. […] Duchenne is caused when very little or no dystrophin is made by the DMD gene because the DMD gene has a defect. […] The genetic defect that causes Duchenne can either be inherited (passed down through the family) or caused by a new change in the DMD gene that occurs in the child. […] This new genetic change is known as a spontaneous mutation and is the cause in more than one third of cases of Duchenne. […] Duchenne is caused by a fault or mutation in the DMD gene. […] There are three different types of changes or mutations in the DMD gene that can cause Duchenne: Deletions of one or more whole exons this is the most common type of mutation and is the cause of around 70% of cases of Duchenne. […] Duplications (additions) of whole exons this type of mutation is the cause of around 10% of cases of Duchenne. […] Other small changes in parts of the genetic code, for example point mutations this type of mutation is the cause of around 20% of cases of Duchenne.

• #3 Causes/Inheritance – Congenital Muscular Dystrophy (CMD) – Diseases | Muscular Dystrophy Association

  https://www.mda.org/disease/congenital-muscular-dystrophy/causes-inheritance

  Muscle cells are embedded in a web-like structure known as the extracellular matrix (ECM). Many CMDs are due to mutations in glycoproteins themselves, or in the enzymes that create them. One group of CMDs are due to mutations in genes that help glycosylate (add sugar molecules to) the protein alpha-dystroglycan, a key glycoprotein of the ECM. […] Loss of glycoproteins due to mutation interferes with normal muscle function. A consequence of most CMD-causing mutations is increased susceptibility to cellular injury from normal contraction, and/or a reduction in the ability to repair damage. […] In the mid-1990s, researchers found that a deficiency of a protein then called merosin and now more often called laminin 211 was the underlying cause of at least some cases of CMD. […] As the 20th century ended, researchers began to suspect that Ullrichs disease, now known as Ullrich CMD, was caused by a lack of collagen 6, a ropelike protein located in the area where laminin 211 is found.

• #3 DUCHENNE MUSCULAR DYSTROPHY: EXPLORING CAUSES, SYMPTOMS, AND RECENT BREAKTHROUGH RESEARCH | Mya Care

  https://myacare.com/blog/duchenne-muscular-dystrophy-exploring-causes-symptoms-and-recent-breakthrough-research

  Duchenne Muscular Dystrophy (DMD) is a rare recessive genetic neuromuscular disease that causes the slow degeneration of muscle fibers and progressive limb weakness. The condition results from genetic mutations in the DMD gene, which prevents the production of dystrophin, a vital protein required to keep muscle cell membranes intact. DMD is the most severe form of disease within the spectrum of inherited muscular dystrophies, all of which arise due to dystrophin gene mutations. […] The cause of DMD is a mutation in the DMD gene, which is a gene that codes for dystrophin and is located on chromosome X (or Xp21). […] Dystrophin is a protein that helps keep muscle cells intact and stable by connecting muscle filaments inside muscle cells to the cell wall. This reinforces the muscles structure and ability to contract. It also helps to transmit the force generated by contracting muscle to the tendon and bone. Without dystrophin, both muscle and bone become more vulnerable to damage and degeneration.

• #3 Muscular Dystrophy – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560582/

  Muscular dystrophy most often results from defective or absent glycoproteins in the muscle membrane. […] Various types of muscular dystrophy are associated with distinct gene deletions or mutations, giving rise to diverse enzymatic or metabolic defects. […] While the genetic mutations causing muscular dystrophy may differ, the underlying mechanism of muscle degeneration and loss remains similar across all types of the disease. […] Although the phenotypic characteristics of certain muscular dystrophies are well-defined, the spectrum produced by mutations in various genes overlap, leading to nonallelic heterogeneity. […] Recognizing nonallelic heterogeneity is crucial for several reasons. […] Phenocopies can arise when nongenetic diseases simulate the symptoms of a genetic disorder. […] It is important to note that muscular dystrophy exhibits variable expressivity and incomplete penetrance, contributing to its manifestations across a phenotypic spectrum in different affected individuals, highlighting the concept of variable expressivity.

• #3

  https://continentalhospitals.com/diseases/muscular-dystrophy/

  These genetic abnormalities disrupt the normal processes within muscle cells, eventually resulting in muscle wasting and loss of strength. While understanding the genetic causes of muscular dystrophy is crucial, it is also important to note that environmental factors can influence disease progression. Factors such as diet, exercise, and exposure to toxins may interact with genetic predispositions and impact the severity and progression of symptoms. […] By delving into the causes of muscular dystrophy, researchers can gain valuable insights into potential treatment options and interventions. Additionally, understanding these causes allows for improved genetic counseling services for families at risk or already affected by this condition.

• #4 Muscular Dystrophy – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560582/

  Muscular dystrophy comprises a group of genetic disorders characterized by progressive muscle weakness and wasting, with a global incidence of approximately 1 in 5,000 individuals. […] The root cause of muscular dystrophy lies in mutations affecting genes responsible for muscle structure and function, leading to the gradual degeneration and loss of muscle fibers. […] Muscular dystrophy can result from mutations in various genes and may be inherited in an X-linked, autosomal dominant, or autosomal recessive manner. […] Changes in the X-linked gene DMD, which encodes dystrophin, are the most frequent cause of muscular dystrophy. […] It is important to note that mutations in dystrophin also create allelic heterogeneity. […] Mutations in the DMD gene, for example, may give rise to either Duchenne or the less severe Becker muscular dystrophy, depending on the extent of the lack of protein.

• #4 Causes/Inheritance – Congenital Muscular Dystrophy (CMD) – Diseases | Muscular Dystrophy Association

  https://www.mda.org/disease/congenital-muscular-dystrophy/causes-inheritance

  Muscle cells are embedded in a web-like structure known as the extracellular matrix (ECM). Many CMDs are due to mutations in glycoproteins themselves, or in the enzymes that create them. One group of CMDs are due to mutations in genes that help glycosylate (add sugar molecules to) the protein alpha-dystroglycan, a key glycoprotein of the ECM. […] Loss of glycoproteins due to mutation interferes with normal muscle function. A consequence of most CMD-causing mutations is increased susceptibility to cellular injury from normal contraction, and/or a reduction in the ability to repair damage. […] In the mid-1990s, researchers found that a deficiency of a protein then called merosin and now more often called laminin 211 was the underlying cause of at least some cases of CMD. […] As the 20th century ended, researchers began to suspect that Ullrichs disease, now known as Ullrich CMD, was caused by a lack of collagen 6, a ropelike protein located in the area where laminin 211 is found.

• #4 Muscular Dystrophy – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560582/

  Muscular dystrophy most often results from defective or absent glycoproteins in the muscle membrane. […] Various types of muscular dystrophy are associated with distinct gene deletions or mutations, giving rise to diverse enzymatic or metabolic defects. […] While the genetic mutations causing muscular dystrophy may differ, the underlying mechanism of muscle degeneration and loss remains similar across all types of the disease. […] Although the phenotypic characteristics of certain muscular dystrophies are well-defined, the spectrum produced by mutations in various genes overlap, leading to nonallelic heterogeneity. […] Recognizing nonallelic heterogeneity is crucial for several reasons. […] Phenocopies can arise when nongenetic diseases simulate the symptoms of a genetic disorder. […] It is important to note that muscular dystrophy exhibits variable expressivity and incomplete penetrance, contributing to its manifestations across a phenotypic spectrum in different affected individuals, highlighting the concept of variable expressivity.

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