Table 1. Novel congenital myopathy disease genes, 2015–2018.

Gene	Findings	References
MYL1	Recessive loss-of-function variants were identified in two probands with severe myopathy characterised by loss of hypotrophic type II myofibres on biopsy.	8
MYO18B	Recessive variants were identified in a patient with nemaline myopathy and cardiomyopathy and in a family presenting with Klippel–Feil anomaly and myopathy.	9, 10
MYPN	Recessive loss-of-function mutations were associated with childhood onset, slowly progressive myopathy with nemaline bodies (including intranuclear rods), and caps on skeletal muscle biopsy. Patient biopsies showed a substantial reduction in myopalladin. Some patients also presented with cardiac involvement.	11, 12
PPA2 a	Recessive variants are associated with sudden cardiac death in infants and young adults. Skeletal muscle from one mildly myopathic infant displayed nemaline bodies.	13, 14
PYROXD1	Recessive variants were identified in five families in which affected individuals presented with an early onset myopathy characterised by generalised skeletal muscle weakness and the presence of internal nuclei and myofibrillar aggregates on biopsy.	15
RYR3 a	Recessive missense variants were identified in a patient with childhood-onset nemaline myopathy.	16

^aOnly in isolated probands. Additional cases/families are required to support PPA2 and RYR3 as congenital myopathy disease genes.