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Congenital myopathy 18

Synonyms
DHPR CONGENITAL MYOPATHY; DIHYDROPYRIDINE RECEPTOR CONGENITAL MYOPATHY; Myopathy, congenital, due to dihydropyridine receptor defect

Summary

Congenital myopathy-18 (CMYO18) is a disorder of the skeletal muscle characterized by the onset of symptoms of muscle weakness in early childhood, including in utero and infancy. There is clinical heterogeneity in the manifestations and severity, ranging from fetal akinesia sequence causing early death to onset of symptoms in adulthood. Most affected individuals show delayed motor development with generalized hypotonia and progressive axial and limb muscle weakness beginning soon after birth or in infancy. Additional features may include swallowing difficulties, external ophthalmoplegia, ptosis, high-arched palate, and respiratory insufficiency, which can lead to death in severe cases. Muscle biopsy shows variable morphologic abnormalities, including alveolar changes in the intermyofibrillar network, fiber size variability, focal disorganization, internal nuclei, and dilated sarcoplasmic reticulum and T-tubules. The disorder results from a defect in excitation-contraction coupling in skeletal muscle (Schartner et al., 2017; Ravenscroft et al., 2021; Mauri et al., 2021; Yis et al., 2019). For a discussion of genetic heterogeneity of congenital myopathy, see CMYO1A (117000). [from OMIM]

Genes See tests for all associated and related genes

  • Also known as: CACNL1A3, CCHL1A3, CMYO18, CMYP18, Cav1.1, DHPRM, HOKPP, HOKPP1, MHS5, TTPP1, hypoPP, CACNA1S
    Summary: calcium voltage-gated channel subunit alpha1 S

Clinical features

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Imported from Human Phenotype Ontology (HPO)

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