Congenital Myopathies
Original Editor - Niha Mulla
Top Contributors - Niha Mulla and Mila Andreew
Introduction[edit | edit source]
Congenital myopathies are a very broad term of rare disorders present at birth. The term Congenital myopathy is reserved for a group of rare, heterogenous, inherited, primary muscle disorders that cause Gross motor delay, poor coordination, and fascial weakness; various orthopedic considerations include foot deformities, joint contractures, hip dysplasia and scoliosis. Congenital myopathy also causes hypotonia and weakness at birth or during the neonatal period and, in some cases, delayed motor development later in childhood.[1][2][3][4][5][6][7]
Description:[edit | edit source]
As described above, Congenital myopathies are rare conditions representing a wide range of disorders in muscle development and function that cause muscle hypotonia and developmental delay. Over twenty genes have been associated with congenital myopathy subtypes. Facial and respiratory muscle weaknesses are common too.
Congenital myopathy differs in severity, and onset of symptoms. Symptoms can be present from birth, or they can slowly progress throughout the infancy and childhood. [7] [8][9]
Pathophysiology[edit | edit source]
There are twenty different genes that can be affected in congenital myopathy and the symptoms, of the disease depends on which gene is affected.
As per Matthew Harmelink, MD and team from medspace, “there are variations among each gene and Occasionally, these result in phenotypic overlap between genes as well as genes causing congenital myopathy to occasionally have phenotypes more consistent with congenital muscular dystrophies, limb-girdle muscular dystrophies, or even possible neuropathic or neuromuscular junction diseases”. [10]
Epidemiology[edit | edit source]
Congenital myopathies are rare and tend to be less severe than congenital muscular dystrophies. Each type of congenital myopathy is distinguished by an underlying genetic mutation with these disorders have been shown to be inherited in x-linked, autosomal recessive and autosomal dominant forms.[11]
Frequency: The frequency of onset of symptom is found to be 76% during the neonatal period.
Mortality/Morbidity: The largest cause of morbidity and mortality is known to be due to be happening from respiratory and/or feeding failure as a result of muscle function loss.
According to the study by Colombo et al., and as mentioned by Matthew Harmelink, MD and collogues; at birth, neonates with congenital myopathy required respiratory support and nasogastric feeding in 30.4% and 25.2% of cases, respectively. And 12% of patients died within the first year, whereas 74.1% achieved independent ambulation with 62.9% being late walkers.[10]
Sex: Congenital myopathy is an extremely rare disorder that generally affects males and females in equal numbers.
Types of Congenital Myopathy[edit | edit source]
There are many types of myopathies that are congenital, some of them seen more commonly than others are listed below:[1][2][3][12][13][14]
- Nemaline myopathy
- Central core myopathy
- Centronuclear Myopathy
- Congenital Fiber-Type Disproportion
- Myosin Storage Myopathy
- Multiminicore myopathy
- Congenital fiber type disproportion myopathy
- Myotubular myopathy
- Sarcotubular myopathy
- Cylindrical spirals myopathy
Signs & Symptoms[edit | edit source]
Resources[edit | edit source]
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References[edit | edit source]
- ↑ 1.0 1.1 Congenital myopathy. Wikipedia. Wikimedia Foundation; 2021. Available from: https://en.wikipedia.org/wiki/Congenital_myopathy
- ↑ 2.0 2.1 Congenital myopathy. NORD (National Organization for Rare Disorders). 2020. Available from: https://rarediseases.org/rare-diseases/myopathy-congenital-batten-turner-type/#:~:text=Congenital%20myopathy%20(CM)%20is%20an,(mutations)%20in%20specific%20genes.
- ↑ 3.0 3.1 Congenital myopathies: Symptoms, causes & outlook. Cleveland Clinic. Available from: https://my.clevelandclinic.org/health/diseases/22392-congenital-myopathy
- ↑ Lossin C, George Jr AL. Myotonia congenita. Advances in genetics. 2008 Jan 1;63:25-55.
- ↑ Sewry CA, Jimenez-Mallebrera C, Muntoni F. Congenital myopathies. Current opinion in neurology. 2008 Oct 1;21(5):569-75.
- ↑ Romero NB, Clarke NF. Congenital myopathies. Handbook of clinical neurology. 2013 Jan 1;113:1321-36.
- ↑ 7.0 7.1 Nance JR, Dowling JJ, Gibbs EM, Bönnemann CG. Congenital myopathies: an update. Current neurology and neuroscience reports. 2012 Apr;12(2):165-74.
- ↑ Nance JR, Dowling JJ, Gibbs EM, Bönnemann CG. Congenital myopathies: an update. Current neurology and neuroscience reports. 2012 Apr;12(2):165-74.
- ↑ Bodamer O, Patterson M, Dashe J. Congenital myopathies. UpToDate.. Available from: https://www.uptodate.com/contents/congenital-myopathies
- ↑ 10.0 10.1 Matthew Harmelink MD. Congenital myopathies. Background, Pathophysiology, Epidemiology. Medscape; 2019. Available from: https://emedicine.medscape.com/article/1175852-overview
- ↑ Hubbard E. Congenital myopathy. POSNA: Pediatric orthopedic society of north America. Available from: https://posna.org/Physician-Education/Study-Guide/Congenital-Myopathy
- ↑ National Organization for Rare Disorders. Congenital Myopathy. Available from: https://rarediseases.org/rare-diseases/myopathy-congenital-batten-turner-type/
- ↑ National Institute of Neurological Disorders and Stroke. Congenital Myopathy Information Page. Available from: https://www.ninds.nih.gov/Disorders/All-Disorders/Congenital-Myopathy-Information-Page
- ↑ Congenital myopathies. Congenital myopathies | Muscular Dystrophy UK. Available from: https://www.musculardystrophyuk.org/conditions/congenital-myopathies
