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Myosin storage myopathy(CMYO7A)

MedGen UID:
374868
Concept ID:
C1842160
Disease or Syndrome
Synonyms: CMYO7A; Congenital myopathy 7A, myosin storage, autosomal dominant; MYH7-related late-onset scapuloperoneal muscular dystrophy; MYH7-Related Myosin Storage Myopathy; MYOPATHY WITH LYSIS OF TYPE I MYOFIBRILS; MYOPATHY, HYALINE BODY, AUTOSOMAL DOMINANT; SCAPULOPERONEAL MUSCULAR DYSTROPHY; Scapuloperoneal myopathy, MYH7-related; SCAPULOPERONEAL SYNDROME, MYOPATHIC TYPE
SNOMED CT: Myosin storage myopathy (699267007); Hyaline body myopathy (699267007)
 
Gene (location): MYH7 (14q11.2)
 
Monarch Initiative: MONDO:0008409
OMIM®: 608358

Definition

Autosomal dominant myosin storage congenital myopathy-7A (CMYO7A) is a skeletal muscle disorder with wide phenotypic variability. The age at symptom onset can range from early childhood to late adulthood. Affected individuals have proximal muscle weakness affecting the upper and lower limbs and distal muscle weakness of the lower limbs, resulting in gait difficulties and scapular winging (scapuloperoneal myopathy). Additional features may include thin habitus, high-arched palate, foot drop, pes cavus, calf pseudohypertrophy, and decreased reflexes. The severity is also variable: some patients develop respiratory insufficiency, joint contractures, and scoliosis in the first decades, whereas others are clinically unaffected, but show subtle signs of the disorder on examination. Serum creatine kinase may be normal or elevated. The disease is usually slowly progressive and most patients remain ambulatory. Skeletal muscle biopsy can show different abnormalities, including hyaline bodies, type 1 fiber predominance, congenital fiber-type disproportion (CFTD), and nonspecific myopathic changes with myofibrillar disarray. Intrafamilial variability is common (Dye et al., 2006; Pegoraro et al., 2007; review by Tajsharghi and Oldfors, 2013). For a discussion of genetic heterogeneity of congenital myopathy, see CMYO1A (117000). [from OMIM]

Additional description

From MedlinePlus Genetics
Myosin storage myopathy is a condition that causes muscle weakness (myopathy) that does not worsen or worsens very slowly over time. This condition is characterized by the formation of protein clumps, which contain a protein called myosin, within certain muscle fibers. The signs and symptoms of myosin storage myopathy usually become noticeable in childhood, although they can occur later. Because of muscle weakness, affected individuals may start walking later than usual and have a waddling gait, trouble climbing stairs, and difficulty lifting the arms above shoulder level. Muscle weakness also causes some affected individuals to have trouble breathing.  https://medlineplus.gov/genetics/condition/myosin-storage-myopathy

Clinical features

From HPO
Scapular winging
MedGen UID:
66822
Concept ID:
C0240953
Anatomical Abnormality
Abnormal protrusion of the scapula away from the surface of the back.
Shoulder girdle muscle weakness
MedGen UID:
96533
Concept ID:
C0427063
Finding
The shoulder, or pectoral, girdle is composed of the clavicles and the scapulae. Shoulder-girdle weakness refers to lack of strength of the muscles attaching to these bones, that is, lack of strength of the muscles around the shoulders.
Pelvic girdle muscle weakness
MedGen UID:
96534
Concept ID:
C0427064
Finding
Weakness of the muscles of the pelvic girdle (also known as the hip girdle), that is, lack of strength of the muscles around the pelvis.
Calf muscle pseudohypertrophy
MedGen UID:
374276
Concept ID:
C1839666
Finding
Enlargement of the muscles of the calf due to their replacement by connective tissue or fat.
Shoulder girdle muscle atrophy
MedGen UID:
339837
Concept ID:
C1847766
Finding
Amyotrophy affecting the muscles of the shoulder girdle.
Hypertrophic cardiomyopathy
MedGen UID:
2881
Concept ID:
C0007194
Disease or Syndrome
Hypertrophic cardiomyopathy (HCM) is defined by the presence of increased ventricular wall thickness or mass in the absence of loading conditions (hypertension, valve disease) sufficient to cause the observed abnormality.
Falls
MedGen UID:
39084
Concept ID:
C0085639
Finding
A sudden movement downward, usually resulting in injury.
Waddling gait
MedGen UID:
66667
Concept ID:
C0231712
Finding
Weakness of the hip girdle and upper thigh muscles, for instance in myopathies, leads to an instability of the pelvis on standing and walking. If the muscles extending the hip joint are affected, the posture in that joint becomes flexed and lumbar lordosis increases. The patients usually have difficulties standing up from a sitting position. Due to weakness in the gluteus medius muscle, the hip on the side of the swinging leg drops with each step (referred to as Trendelenburg sign). The gait appears waddling. The patients frequently attempt to counteract the dropping of the hip on the swinging side by bending the trunk towards the side which is in the stance phase (in the German language literature this is referred to as Duchenne sign). Similar gait patterns can be caused by orthopedic conditions when the origin and the insertion site of the gluteus medius muscle are closer to each other than normal, for instance due to a posttraumatic elevation of the trochanter or pseudarthrosis of the femoral neck.
Gait disturbance
MedGen UID:
107895
Concept ID:
C0575081
Finding
The term gait disturbance can refer to any disruption of the ability to walk.
Myopathy
MedGen UID:
10135
Concept ID:
C0026848
Disease or Syndrome
A disorder of muscle unrelated to impairment of innervation or neuromuscular junction.
Muscle weakness
MedGen UID:
57735
Concept ID:
C0151786
Finding
Reduced strength of muscles.
Difficulty climbing stairs
MedGen UID:
68676
Concept ID:
C0239067
Finding
Reduced ability to climb stairs.
Difficulty running
MedGen UID:
108251
Concept ID:
C0560346
Finding
Reduced ability to run.
Generalized muscle weakness
MedGen UID:
155433
Concept ID:
C0746674
Sign or Symptom
Generalized weakness or decreased strength of the muscles, affecting both distal and proximal musculature.
Generalized limb muscle atrophy
MedGen UID:
333018
Concept ID:
C1838114
Disease or Syndrome
Generalized (unlocalized) atrophy affecting muscles of the limbs in both proximal and distal locations.
Scapuloperoneal weakness
MedGen UID:
331234
Concept ID:
C1842161
Finding
Scapuloperoneal amyotrophy
MedGen UID:
331235
Concept ID:
C1842162
Finding
Muscular atrophy in the distribution of shoulder girdle and peroneal muscles.
Centrally nucleated skeletal muscle fibers
MedGen UID:
330782
Concept ID:
C1842170
Finding
An abnormality in which the nuclei of sarcomeres take on an abnormally central localization (or in which this feature is found in an increased proportion of muscle cells).
Neck flexor weakness
MedGen UID:
334801
Concept ID:
C1843637
Finding
Weakness of the muscles involved in neck flexion (sternocleidomastoid, longus capitus, longus colli, and scalenus anterior).
Type 1 muscle fiber predominance
MedGen UID:
344274
Concept ID:
C1854387
Finding
An abnormal predominance of type I muscle fibers (in general, this feature can only be observed on muscle biopsy).
EMG: myopathic abnormalities
MedGen UID:
867362
Concept ID:
C4021726
Pathologic Function
The presence of abnormal electromyographic patterns indicative of myopathy, such as small-short polyphasic motor unit potentials.
Reduced vital capacity
MedGen UID:
141657
Concept ID:
C0476408
Finding
An abnormal reduction on the vital capacity, which is defined as the total lung capacity (volume of air in the lungs at maximal inflation) less the residual volume (i.e., volume of air in the lungs following maximal exhalation) of the lung.
Mildly elevated creatine kinase
MedGen UID:
342469
Concept ID:
C1850309
Finding

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  

Recent clinical studies

Etiology

Claeys KG
Dev Med Child Neurol 2020 Mar;62(3):297-302. Epub 2019 Oct 2 doi: 10.1111/dmcn.14365. PMID: 31578728
Tajsharghi H, Oldfors A
Acta Neuropathol 2013 Jan;125(1):3-18. Epub 2012 Aug 5 doi: 10.1007/s00401-012-1024-2. PMID: 22918376Free PMC Article
Ortolano S, Tarrío R, Blanco-Arias P, Teijeira S, Rodríguez-Trelles F, García-Murias M, Delague V, Lévy N, Fernández JM, Quintáns B, Millán BS, Carracedo A, Navarro C, Sobrido MJ
Neuromuscul Disord 2011 Apr;21(4):254-62. Epub 2011 Feb 1 doi: 10.1016/j.nmd.2010.12.011. PMID: 21288719
Oldfors A, Lamont PJ
Adv Exp Med Biol 2008;642:78-91. doi: 10.1007/978-0-387-84847-1_7. PMID: 19181095
Oldfors A
Neuromuscul Disord 2007 May;17(5):355-67. Epub 2007 Apr 16 doi: 10.1016/j.nmd.2007.02.008. PMID: 17434305

Diagnosis

Naderi N, Mohsen-Pour N, Nilipour Y, Pourirahim M, Maleki M, Kalayinia S
BMC Cardiovasc Disord 2023 Oct 4;23(1):487. doi: 10.1186/s12872-023-03538-8. PMID: 37794383Free PMC Article
Claeys KG
Dev Med Child Neurol 2020 Mar;62(3):297-302. Epub 2019 Oct 2 doi: 10.1111/dmcn.14365. PMID: 31578728
Li N, Zhao Z, Shen H, Bing Q, Guo X, Hu J
Neurol Sci 2018 Feb;39(2):333-339. Epub 2017 Nov 24 doi: 10.1007/s10072-017-3192-2. PMID: 29170849
Pegoraro E, Gavassini BF, Borsato C, Melacini P, Vianello A, Stramare R, Cenacchi G, Angelini C
Neuromuscul Disord 2007 Apr;17(4):321-9. Epub 2007 Mar 2 doi: 10.1016/j.nmd.2007.01.010. PMID: 17336526
Oldfors A, Tajsharghi H, Darin N, Lindberg C
Acta Myol 2004 Sep;23(2):90-6. PMID: 15605950

Prognosis

Naderi N, Mohsen-Pour N, Nilipour Y, Pourirahim M, Maleki M, Kalayinia S
BMC Cardiovasc Disord 2023 Oct 4;23(1):487. doi: 10.1186/s12872-023-03538-8. PMID: 37794383Free PMC Article
Tajsharghi H, Oldfors A, Macleod DP, Swash M
Neurology 2007 Mar 20;68(12):962. doi: 10.1212/01.wnl.0000257131.13438.2c. PMID: 17372140
Oldfors A, Tajsharghi H, Darin N, Lindberg C
Acta Myol 2004 Sep;23(2):90-6. PMID: 15605950
Meredith C, Herrmann R, Parry C, Liyanage K, Dye DE, Durling HJ, Duff RM, Beckman K, de Visser M, van der Graaff MM, Hedera P, Fink JK, Petty EM, Lamont P, Fabian V, Bridges L, Voit T, Mastaglia FL, Laing NG
Am J Hum Genet 2004 Oct;75(4):703-8. Epub 2004 Aug 20 doi: 10.1086/424760. PMID: 15322983Free PMC Article

Clinical prediction guides

Naderi N, Mohsen-Pour N, Nilipour Y, Pourirahim M, Maleki M, Kalayinia S
BMC Cardiovasc Disord 2023 Oct 4;23(1):487. doi: 10.1186/s12872-023-03538-8. PMID: 37794383Free PMC Article
Beecroft SJ, van de Locht M, de Winter JM, Ottenheijm CA, Sewry CA, Mohammed S, Ryan MM, Woodcock IR, Sanders L, Gooding R, Davis MR, Oates EC, Laing NG, Ravenscroft G, McLean CA, Jungbluth H
Neuromuscul Disord 2019 Jun;29(6):456-467. Epub 2019 Apr 12 doi: 10.1016/j.nmd.2019.04.002. PMID: 31130376
Viswanathan MC, Tham RC, Kronert WA, Sarsoza F, Trujillo AS, Cammarato A, Bernstein SI
Hum Mol Genet 2017 Dec 15;26(24):4799-4813. doi: 10.1093/hmg/ddx359. PMID: 28973424Free PMC Article
Bánfai Z, Hadzsiev K, Pál E, Komlósi K, Melegh M, Balikó L, Melegh B
BMC Med Genet 2017 Sep 19;18(1):105. doi: 10.1186/s12881-017-0463-y. PMID: 28927399Free PMC Article
Ortolano S, Tarrío R, Blanco-Arias P, Teijeira S, Rodríguez-Trelles F, García-Murias M, Delague V, Lévy N, Fernández JM, Quintáns B, Millán BS, Carracedo A, Navarro C, Sobrido MJ
Neuromuscul Disord 2011 Apr;21(4):254-62. Epub 2011 Feb 1 doi: 10.1016/j.nmd.2010.12.011. PMID: 21288719

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