Congenital muscular dystrophy
Encyclopedia
Congenital muscular dystrophy (CMD) is the term used to describe muscular dystrophy
that is present at birth. CMD describes a number of autosomal recessive diseases of muscle
weakness and possible joint
deformities, present at birth and slowly progressing. Life expectancies for affected individuals vary, although some forms of CMD do not affect life span at all.
Physical and occupational therapy
, surgery, wheelchairs and other assistive technology may be helpful.
Currently there is no cure.
-α2 chain, fukutin-related protein
, LARGE
and fukutin
, amongst others.
A classification for CMDs had been proposed in 2004 by Muntoni and Voit, based on genetic mutation.
Muscular dystrophy
Muscular dystrophy is a group of muscle diseases that weaken the musculoskeletal system and hamper locomotion. Muscular dystrophies are characterized by progressive skeletal muscle weakness, defects in muscle proteins, and the death of muscle cells and tissue.In the 1860s, descriptions of boys who...
that is present at birth. CMD describes a number of autosomal recessive diseases of muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
weakness and possible joint
Joint
A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally.-Classification:...
deformities, present at birth and slowly progressing. Life expectancies for affected individuals vary, although some forms of CMD do not affect life span at all.
Management
Treatment is supportive.Physical and occupational therapy
Occupational therapy
Occupational therapy is a discipline that aims to promote health by enabling people to perform meaningful and purposeful activities. Occupational therapists work with individuals who suffer from a mentally, physically, developmentally, and/or emotionally disabling condition by utilizing treatments...
, surgery, wheelchairs and other assistive technology may be helpful.
Currently there is no cure.
Classification
All such known dystrophies are genetically recessive and result from mutations in a variety of different genes, including those encoding the lamininLaminin
Laminins are major proteins in the basal lamina , a protein network foundation for most cells and organs...
-α2 chain, fukutin-related protein
Fukutin-related protein
Fukutin-related protein is a protein associated with congenital muscular dystrophy.-External Links:* * LOVD mutation database:...
, LARGE
LARGE
Glycosyltransferase-like protein LARGE1 is an enzyme that in humans is encoded by the LARGE gene.- Function :This gene, which is one of the largest in the human genome, encodes a member of the N-acetylglucosaminyltransferase gene family. The function of this gene has not yet been established;...
and fukutin
Fukutin
Fukutin is a eukaryotic protein necessary for the maintenance of muscle integrity, cortical histogenesis, and normal ocular development. Mutations in the fukutin gene have been shown to result in Fukuyama congenital muscular dystrophy characterised by brain malformation - one of the most common...
, amongst others.
A classification for CMDs had been proposed in 2004 by Muntoni and Voit, based on genetic mutation.
- Genes encoding for structural proteins of the basal membrane or extracellular matrixExtracellular matrixIn biology, the extracellular matrix is the extracellular part of animal tissue that usually provides structural support to the animal cells in addition to performing various other important functions. The extracellular matrix is the defining feature of connective tissue in animals.Extracellular...
of the skeletal muscleSkeletal muscleSkeletal muscle is a form of striated muscle tissue existing under control of the somatic nervous system- i.e. it is voluntarily controlled. It is one of three major muscle types, the others being cardiac and smooth muscle...
fibres. - Genes encoding for putative or demonstrated glycosyltransferaseGlycosyltransferaseGlycosyltransferases are enzymes that act as a catalyst for the transfer of a monosaccharide unit from an activated nucleotide sugar to a glycosyl acceptor molecule, usually an alcohol....
s, that in turn affect the glycosylationGlycosylationGlycosylation is the reaction in which a carbohydrate, i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule . In biology glycosylation refers to the enzymatic process that attaches glycans to proteins, lipids, or other organic molecules...
of dystroglycanDystroglycanDystroglycan is a protein that in humans is encoded by the DAG1 gene.Dystroglycan is one of the dystrophin-associated glycoproteins, which is encoded by a 5.5 kb transcript in Homo sapiens by chromosome 3. There are two exons that are separated by a large intron...
, an external membrane protein of the basal membrane. - Other
| Name | Abbreviation | Group | OMIM | Gene and locus |
|---|---|---|---|---|
| Laminin-α2–deficient CMD | MDC1A | basal membrane/extracellular matrix | LAMA2 at 6q22-q23 | |
| Ullrich congenital muscular dystrophy Ullrich congenital muscular dystrophy Ullrich congenital muscular dystrophy is a form of congenital muscular dystrophy.It is associated with variants of type VI collagen.It is commonly associated with muscle weakness.... |
UCMDs 1, 2 and 3 | basal membrane/extracellular matrix | COL6A1 COL6A1 Collagen alpha-1 chain is a protein that in humans is encoded by the COL6A1 gene.- Function :The collagens are a superfamily of proteins that play a role in maintaining the integrity of various tissues. Collagens are extracellular matrix proteins and have a triple-helical domain as their common... at 2q37, COL6A2 COL6A2 Collagen alpha-2 chain is a protein that in humans is encoded by the COL6A2 gene.- Function :This gene encodes one of the three alpha chains of type VI collagen, a beaded filament collagen found in most connective tissues. The product of this gene contains several domains similar to von Willebrand... at 21q22.3, COL6A3 COL6A3 Collagen alpha-3 chain is a protein that in humans is encoded by the COL6A3 gene.- Function :This gene encodes the alpha 3 chain, one of the three alpha chains of type VI collagen, a beaded filament collagen found in most connective tissues. The alpha 3 chain of type VI collagen is much larger than... at 21q22.3 |
|
| Walker-Warburg syndrome Walker-Warburg syndrome Walker–Warburg syndrome , also called Warburg syndrome, Chemke syndrome, HARD syndrome , Pagon syndrome, cerebroocular dysgenesis or cerebroocular dysplasia-muscular dystrophy syndrome , is a rare form of autosomal recessive congenital muscular dystrophy... |
WWS | glycosylation of dystroglycan | POMT1 POMT1 Protein O-mannosyl-transferase 1 is an enzyme that in humans is encoded by the POMT1 gene. It is a member of the dolichyl-phosphate-mannose-protein mannosyltransferases.- Function :... at 9q34.1 and POMT2 POMT2 Protein O-mannosyl-transferase 2 is an enzyme that in humans is encoded by the POMT2 gene.- Function :POMT2 encodes an integral membrane protein of the endoplasmic reticulum that shares significant sequence similarity with a family of protein O-mannosyltransferases of S. cerevisiae... at 14q24.3 |
|
| Muscle-eye-brain disease | MEB | glycosylation of dystroglycan | POMGNT1 POMGNT1 Protein O-linked-mannose beta-1,2-N-acetylglucosaminyltransferase 1 is an enzyme that in humans is encoded by the POMGNT1 gene.- Function :... at 1p34-p33 |
|
| Fukuyama CMD | FCMD | glycosylation of dystroglycan | FKTN at 9q31 | |
| CMD plus secondary laminin deficiency 1 | MDC1B | glycosylation of dystroglycan | ? at 1q42 | |
| CMD plus secondary laminin deficiency 2 | MDC1C | glycosylation of dystroglycan | FKRP at 19q13.3 | |
| CMD with mental retardation Mental retardation Mental retardation is a generalized disorder appearing before adulthood, characterized by significantly impaired cognitive functioning and deficits in two or more adaptive behaviors... and pachygyria Pachygyria Pachygyria is a congenital malformation of the cerebral hemisphere. It results in unusually thick convolutions of the cerebral cortex. Typically, children have developmental delay and seizures, the onset and severity depending on the severity of the cortical malformation... |
MDC1D | glycosylation of dystroglycan | LARGE LARGE Glycosyltransferase-like protein LARGE1 is an enzyme that in humans is encoded by the LARGE gene.- Function :This gene, which is one of the largest in the human genome, encodes a member of the N-acetylglucosaminyltransferase gene family. The function of this gene has not yet been established;... at 22q12.3-q13.1 |
|
| Rigid spine with muscular dystrophy Type 1 | RSMD1 | other | SEPN1 SEPN1 Selenoprotein N is a protein that in humans is encoded by the SEPN1 gene.- Function :This gene encodes a selenoprotein, which contains a selenocysteine residue at its active site. The selenocysteine is encoded by the UGA codon that normally signals translation termination... at 1p36-p35 |
|
| ITGA7 ITGA7 Integrin alpha-7 is a protein that in humans is encoded by the ITGA7 gene.-Interactions:ITGA7 has been shown to interact with FHL2 and FHL3.-External links:* Info with links in the... at 12q13 |