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Congenital multicore myopathy with external ophthalmoplegia

Synonyms
Congenital myopathy 1B, autosomal recessive; MULTICORE MYOPATHY; Minicore myopathy; Minicore myopathy with external ophthalmoplegia; Multicore myopathy with external ophthalmoplegia; Multiminicore disease with external ophthalmoplegia

Summary

Congenital myopathy-1B (CMYO1B) is an autosomal recessive disorder of skeletal muscle characterized by severe hypotonia and generalized muscle weakness apparent soon after birth or in early childhood with delayed motor development, generalized muscle weakness and atrophy, and difficulty walking or running. Affected individuals show proximal muscle weakness with axial and shoulder girdle involvement, external ophthalmoplegia, and bulbar weakness, often resulting in feeding difficulties and respiratory insufficiency. Orthopedic complications such as joint laxity, distal contractures, hip dislocation, cleft palate, and scoliosis are commonly observed. Serum creatine kinase is normal. The phenotype is variable in severity (Jungbluth et al., 2005; Bharucha-Goebel et al., 2013). Some patients show symptoms in utero, including reduced fetal movements, polyhydramnios, and intrauterine growth restriction. The most severely affected patients present in utero with fetal akinesia, arthrogryposis, and lung hypoplasia resulting in fetal or perinatal death (McKie et al., 2014). Skeletal muscle biopsy of patients with recessive RYR1 mutations can show variable features, including multiminicores (Ferreiro and Fardeau, 2002), central cores (Jungbluth et al., 2002), congenital fiber-type disproportion (CFTD) (Monnier et al., 2009), and centronuclear myopathy (Wilmshurst et al., 2010). For a discussion of genetic heterogeneity of congenital myopathy, see CMYO1A (117000). [from OMIM]

Available tests

56 tests are in the database for this condition.

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Clinical tests (56 available)

Molecular Genetics Tests

Genes See tests for all associated and related genes

  • Also known as: CCO, CMYO1A, CMYO1B, CMYP1A, CMYP1B, KDS, MHS, MHS1, PPP1R137, RYDR, RYR, RYR-1, SKRR, RYR1
    Summary: ryanodine receptor 1

Clinical features

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Imported from Human Phenotype Ontology (HPO)

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