| Namespace | disease_ontology | Obsolete | false |
| description | A congenital myopathy that is characterized by onset of muscle weakness in utero or soon after birth and that has_material_basis_in homozygous or compound heterozygous mutation in the SCN4A gene on chromosome 17q23. Biallelic mutation in the SCN4A gene also causes severe fetal congenital myopathy 22B. |