An autosomal recessive myopathy caused by mutations in the KLHL40 gene, encoding Kelch-like protein 40. The phenotype is highly variable, and as such attempts at classification by clinical features is not optimal. Generally, affected individuals have generalized muscle weakness, and typically involves proximal muscles, the face, bulbar and respiratory muscles. The disease is Monarch Disease Ontology term MONDO_0014138 (nemaline myopathy 8). Also known as: KLHL40 nemaline myopathy, NEM8, nemaline myopathy 8, autosomal recessive, nemaline myopathy caused by mutation in KLHL40, nemaline myopathy type 8.