Congenital myopathies

Conventionally, they are defined as muscular diseases characterized by an anomaly of muscle structure(s). They are little or not progressive and result mainly in orthopedic problems (scoliosis, contractures). Their morbidity and mortality are mainly related to respiratory failure. Primary cardiac involvement is very rare and intelligence is often normal.


Thanks to advances in genetics and molecular biology, some histology-based names have been changed.

Some of these myopathies (*) are associated with a risk of malignant hyperthermia.


From a genetic point of view, they are classified as follows with the acronym CMYO for Congenital MYOpathy: (see disease-specific data sheet for more details)


- *CMYO1A, [MIM 117 000] mutation of the RYR1 gene (19q13): central core disease or Shy-Magee syndrome.

- *CMYO1B, [MIM 255 320], biallelic mutations of the RYR1 gene (19q13): minicore, multicore or multiminicore myopathy with or without external ophthalmoplegia.

- CMYO2A, [MIM 161 800], mutation of the ACTA1 gene (1q42): nemaline rod myopathy type 3

- CMYO2B, [MIM 620 265], biallelic mutations of the ACTA1 gene (1q42): autosomal recessive severe infantile congenital myopathy

- CMYO2C, [MIM 620 278], mutation of the ACTA1 gene (1q42): autosomal dominant severe infantile congenital myopathy

- CMYO3, [MIM 255 310], mutation of the TMP3 gene (1q21): muscular dystrophy with spinal stiffness (rigid spine syndrome); formerly: Eichsfeld-type congenital muscular dystrophy; severe classic minicore, multicore or multiminicore myopathy; desmin-positive congenital muscular dystrophy with early spinal involvement

- *CMYO4A, [MIM 255 310], mutation of theTMP3 gene (1q21): congenital myopathy with disproportion of muscle fiber types; rod myopathy type 1, CAP myopathy type 1

- CMYO4B, [MIM 609 284], mutation of the TMP3 gene (1q21); type 4A but autosomal recessive transmission

- CMYO5, [MIM 611 705], mutation of the TTN gene (2q31): Salih myopathy, with cardiomyopathy

- CMYO6, [MIM 605 637], mutation of the MYH2 gene (17p13): proximal myopathy with ophthalmoplegia, ring vacuole myopathy, inclusion myopathy type 3

- CMYO7A, [MIM 608 358], mutation of the MYH7 gene (14q11): myosin myopathy, hyaline body myopathy, myopathy with type I microfibrillar lysis, scapuloperoneal myopathy

- CMYO7B, [MIM 255 160], mutation of the MYH7 gene (14q11): autosomal recessive scapuloperoneal myopathy

- CMYO8, [MIM 618 654], mutation of the ACTN2 gene (1q43): multi-axis myopathy and z-line abnormalities

- CMYO9A, [MIM 618 822], mutation of the FXR1 gene (3q38): congenital myopathy with respiratory failure and multiple fractures

- CMYO9B, [MIM 618 823], mutation of the FXR1 gene (3q38): proximal congenital myopathy with minicores

- CMYO10A, [MIM 614 399], mutation of the MEGF10 gene (5q23): myopathy syndrome, areflexia, respiratory failure and early-onset dysphagia

- CMYO10B, [MIM 620 249], mutation of the MEGF10 gene (5q23): moderate form of CMYO10A

- CMYO11, [MIM 619 967], mutation of the HACD1 gene (10p12): non-progressive congenital myopathy

- CMYO12, [MIM 612 540], mutation of the CNTN1 gene (12q12): Compton-North type congenital myopathy with minicores

- *CMYO13, [MIM 255 995], mutation of the STAC3 gene (12q13): Native American myopathy (Bailey-Bloch myopathy)

- CMYO14, [MIM 618 414], mutation of the MYL1 gene (2q34): congenital myopathy with type 2 fiber atrophy

- CMYO15, [MIM 620 161], mutation of the TNNC2 gene (20q13): congenital myopathy with neonatal respiratory failure

- CMYO16, [MIM 618 524], mutation of the MYBPC1 gene (12q23): congenital myopathy with tremors

- CMYO17, [MIM 618 975], mutation of the MYOD1 gene (11p15): congenital myopathy with relaxation of the diaphragm, respiratory insufficiency and dysmorphic facies

- *CMYO18, [MIM 620 246], mutation of the CACNA1S gene (1q32): congenital myopathy with dihydropyridine receptor abnormality; other mutations of this gene lead to type 1 familial periodic paralysis.

- CMYO19, [MIM 618 578], mutation of the PAX7 gene (1p36): progressive congenital myopathy (scoliosis)

- CMYO20, [MIM 620 310], mutation of the RYR3 gene (15q13): congenital myopathy (sometimes rod)

- CMYO21, [MIM 620 326], mutation of the DNAJB4 gene (1p31): congenital myopathy with early respiratory distress

- CMYO22A, [MIM 620 351], mutation of the SCN4A gene (17q23): classic congenital myopathy; other mutations of this gene may result in familial hyperkalemic paralysis, K-aggravated myotonia, or congenital myasthenic syndrome (16)

- CMYO22B, [MIM 620 369], mutation of the SCN4A gene (17q23): severe congenital myopathy; other mutations of this gene may result in familial hyperkalemic paralysis, K-aggravated myotonia, von Eulenburg paramyotonia or congenital myasthenic syndrome (16)

- CMYO23, [MIM 609 285], mutation of the TPM2 gene (9p13): nemalin myopathy type 4, cap myopathy type 2

- CMYO24, [MIM 617 336], mutation of the MYPN gene (10q21): nemalin myopathy type 11


Other congenital myopathies have their own classifications (see these terms):


-        Rod myopathies (nemaline rod)

-        Centronuclear myopathies

-        Cap myopathies

-        Centronuclear myopathies

-        Myopathy with tubular aggregates


Some structural descriptions have not yet been classified:


-        sarcotubular myopathy

-        *myopathy with fingerprint bodies

-        myopathy with collar fibers

-        trilaminar myopathy

-        mosaic fiber myopathy

-        wide band A disease

-        lamellar body myopathy

-        myopathy with excess muscle spindles

-        zebra body myopathy


References : 


Updated: March 2025