U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Congenital myopathy with reduced type 2 muscle fibers(MYOFTA; CMYP14)

MedGen UID:
1672638
Concept ID:
C5193081
Disease or Syndrome
Synonyms: CONGENITAL MYOPATHY 14; MYOPATHY, CONGENITAL, WITH FAST-TWITCH (TYPE II) FIBER ATROPHY
SNOMED CT: Congenital myopathy with type II fiber atrophy (1255274002); Congenital myopathy with reduced type II muscle fibers (1255274002); Congenital myopathy with fast-twitch fiber atrophy (1255274002); Congenital myopathy with reduced type 2 muscle fibers (1255274002); Congenital myopathy with type 2 muscle fiber atrophy (1255274002)
Modes of inheritance:
Autosomal recessive inheritance
MedGen UID:
141025
Concept ID:
C0441748
Intellectual Product
Source: Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele).
 
Gene (location): MYL1 (2q34)
 
Monarch Initiative: MONDO:0034109
OMIM®: 618414
Orphanet: ORPHA544602

Definition

Congenital myopathy-14 (CMYO14) is an autosomal recessive skeletal muscle disorder characterized by onset of severe muscle weakness apparent at birth and sometimes in utero. Affected infants have difficulty breathing independently and usually require mechanical ventilation for variable lengths of time. Other features include delayed motor development with delayed walking, hypo- or areflexia, and high-arched palate. Skeletal muscle biopsy shows variation in fiber size with specific atrophy of the fast-twitch type II fibers. Cardiac muscle is not affected (summary by Ravenscroft et al., 2018). For a discussion of genetic heterogeneity of congenital myopathy, see CMYO1A (117000). [from OMIM]

Clinical features

From HPO
Knee flexion contracture
MedGen UID:
98042
Concept ID:
C0409355
Finding
A type of knee joint contracture in which the knee is in a fixed bent (flexed) configuration such that it cannot be straightened actively or passively.
Feeding difficulties
MedGen UID:
65429
Concept ID:
C0232466
Finding
Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it.
Nasogastric tube feeding
MedGen UID:
847783
Concept ID:
C3853581
Medical Device
The condition of inability to eat normally treated by placement of a thin tube through the nose into the stomach that is then used to carry food.
Areflexia
MedGen UID:
115943
Concept ID:
C0234146
Finding
Absence of neurologic reflexes such as the knee-jerk reaction.
Persistent head lag
MedGen UID:
256151
Concept ID:
C1141883
Finding
The Premie-Neuro and the Dubowitz Neurological Examination score head lag in the same manner. Scoring for both is as follows
Motor delay
MedGen UID:
381392
Concept ID:
C1854301
Finding
A type of Developmental delay characterized by a delay in acquiring motor skills.
Hypotonia
MedGen UID:
10133
Concept ID:
C0026827
Finding
Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.
Proximal muscle weakness
MedGen UID:
113169
Concept ID:
C0221629
Finding
A lack of strength of the proximal muscles.
Neck muscle weakness
MedGen UID:
66808
Concept ID:
C0240479
Finding
Decreased strength of the neck musculature.
Flexion contracture
MedGen UID:
83069
Concept ID:
C0333068
Anatomical Abnormality
A flexion contracture is a bent (flexed) joint that cannot be straightened actively or passively. It is thus a chronic loss of joint motion due to structural changes in muscle, tendons, ligaments, or skin that prevents normal movement of joints.
Elbow flexion contracture
MedGen UID:
98367
Concept ID:
C0409338
Acquired Abnormality
An elbow contracture that limits the ability of the elbow joint to be extended (straightened), meaning that the elbow is fixed in an flexed (bent) position.
Hip contracture
MedGen UID:
140815
Concept ID:
C0409354
Acquired Abnormality
Lack of full passive range of motion (restrictions in flexion, extension, or other movements) of the hip joint resulting from structural changes of non-bony tissues, such as muscles, tendons, ligaments, joint capsules and/or skin.
Weakness of facial musculature
MedGen UID:
98103
Concept ID:
C0427055
Disease or Syndrome
Reduced strength of one or more muscles innervated by the facial nerve (the seventh cranial nerve).
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.
Axial muscle weakness
MedGen UID:
334472
Concept ID:
C1843697
Finding
Reduced strength of the axial musculature (i.e., of the muscles of the head and neck, spine, and ribs).
Increased variability in muscle fiber diameter
MedGen UID:
336019
Concept ID:
C1843700
Finding
An abnormally high degree of muscle fiber size variation. This phenotypic feature can be observed upon muscle biopsy.
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: decremental response of compound muscle action potential to repetitive nerve stimulation
MedGen UID:
892749
Concept ID:
C4021728
Finding
A compound muscle action potential (CMAP) is a type of electromyography (EMG). CMAP refers to a group of almost simultaneous action potentials from several muscle fibers in the same area evoked by stimulation of the supplying motor nerve and are recorded as one multipeaked summated action potential. This abnormality refers to a greater than normal decrease in the amplitude during the course of the investigation.
Increased endomysial connective tissue
MedGen UID:
867771
Concept ID:
C4022161
Finding
An increased volume of the endomysium, which is a connective tissue sheath that surrounds each muscule fiber. Together, bundles of muscle fibers form a fasciculus, surrounded by another layer of connective tissue called the perimysium.
Apnea
MedGen UID:
2009
Concept ID:
C0003578
Sign or Symptom
Lack of breathing with no movement of the respiratory muscles and no exchange of air in the lungs. This term refers to a disposition to have recurrent episodes of apnea rather than to a single event.
Respiratory failure
MedGen UID:
257837
Concept ID:
C1145670
Disease or Syndrome
A severe form of respiratory insufficiency characterized by inadequate gas exchange such that the levels of oxygen or carbon dioxide cannot be maintained within normal limits.
Respiratory insufficiency due to muscle weakness
MedGen UID:
812797
Concept ID:
C3806467
Finding
Abnormal circulating creatine kinase concentration
MedGen UID:
868058
Concept ID:
C4022449
Finding
Any deviation from the normal circulating creatine kinase concentration.
High palate
MedGen UID:
66814
Concept ID:
C0240635
Congenital Abnormality
Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective).
Myopathic facies
MedGen UID:
90695
Concept ID:
C0332615
Finding
A facial appearance characteristic of myopathic conditions. The face appears expressionless with sunken cheeks, bilateral ptosis, and inability to elevate the corners of the mouth, due to muscle weakness.
Polyhydramnios
MedGen UID:
6936
Concept ID:
C0020224
Pathologic Function
The presence of excess amniotic fluid in the uterus during pregnancy.
Decreased fetal movement
MedGen UID:
68618
Concept ID:
C0235659
Finding
An abnormal reduction in quantity or strength of fetal movements.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVCongenital myopathy with reduced type 2 muscle fibers

Recent clinical studies

Therapy

Wei C, Stock L, Valanejad L, Zalewski ZA, Karns R, Puymirat J, Nelson D, Witte D, Woodgett J, Timchenko NA, Timchenko L
FASEB J 2018 Apr;32(4):2073-2085. Epub 2018 Jan 5 doi: 10.1096/fj.201700700R. PMID: 29203592Free PMC Article

Prognosis

Martin F, Kana V, Mori AC, Fischer D, Parkin N, Boltshauser E, Rushing EJ, Klein A
Eur J Pediatr 2014 Dec;173(12):1691-4. Epub 2014 Apr 8 doi: 10.1007/s00431-014-2314-6. PMID: 24706162
Figarella-Branger D, Putzu GA, Bouvier-Labit C, Pouget J, Chateau D, Fardeau M, Pellissier JF
Neuromuscul Disord 1999 Dec;9(8):580-6. doi: 10.1016/s0960-8966(99)00058-9. PMID: 10619716

Clinical prediction guides

Massana Muñoz X, Buono S, Koebel P, Laporte J, Cowling BS
Hum Mol Genet 2019 Dec 15;28(24):4067-4077. doi: 10.1093/hmg/ddz249. PMID: 31628461
Wang Y, Melkani GC, Suggs JA, Melkani A, Kronert WA, Cammarato A, Bernstein SI
Mol Biol Cell 2012 Jun;23(11):2057-65. Epub 2012 Apr 11 doi: 10.1091/mbc.E12-02-0120. PMID: 22496423Free PMC Article
Wilmshurst JM, Lillis S, Zhou H, Pillay K, Henderson H, Kress W, Müller CR, Ndondo A, Cloke V, Cullup T, Bertini E, Boennemann C, Straub V, Quinlivan R, Dowling JJ, Al-Sarraj S, Treves S, Abbs S, Manzur AY, Sewry CA, Muntoni F, Jungbluth H
Ann Neurol 2010 Nov;68(5):717-26. doi: 10.1002/ana.22119. PMID: 20839240
Hong JM, Kim SM, Sunwoo IN, Kim SH, Kim TS, Shim DS, Choi YC
Yonsei Med J 2010 Mar;51(2):225-30. Epub 2010 Feb 12 doi: 10.3349/ymj.2010.51.2.225. PMID: 20191014Free PMC Article
Nakanishi T, Sakauchi M, Kaneda Y, Tomimatsu H, Saito K, Nakazawa M, Osawa M
Pediatrics 2006 Jun;117(6):e1187-92. Epub 2006 May 22 doi: 10.1542/peds.2005-2469. PMID: 16717122

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...