| Main clinical features
|
severe congenital myopathy characterized by early-onset generalized muscle weakness and hypotonia with respiratory insufficiency and feeding difficulties
antenatal features of the disorder, including polyhydramnios, decreased or absent fetal movements, and joint contractures, with frequent premature birth
most patients died of respiratory failure in the neonatal period
skeletal muscle biopsy showed nemaline bodies and atrophic myofibers with increased connective tissue; electron microscopy showed that the nemaline bodies resembled short, thickened Z discs, often in doublets interconnected by filaments |