MYH2-associated myopathy caused by novel compound heterozygous mutations: a case report and literature review

MYH2-associated myopathy is a group of congenital heterogeneous diseases. Case reports with MYH2-associated myopathy due to compound heterozygous mutations are rare. We report a 63-year-old Asian female who presented with bilateral ptosis and limb weakness for over 10 years. The orbits magnetic resonance imaging showed no abnormalities. Muscle biopsy revealed characteristics consistent with congenital neuromuscular disease with uniform type 1 fibers. Genetic testing identified compound heterozygous mutations in the MYH2 gene: a heterozygous mutation in exon 30, c.4066G>T (chr17:10430037, p.E1356X) and a heterozygous mutation in exon 38, c.5473-1G>A (chr17:10426730, splicing). The novel gene mutations are considered potential pathogenic variants. MYH2-associated myopathy was diagnosed. Following treatment with cytidine diphosphate choline, coenzyme Q10, methylcobalamin, and idebenone, her ocular symptoms showed slight improvement before discharge. This case highlights the importance of genetic testing in diagnosing rare myopathies and expands the genetic spectrum of MYH2-associated myopathy.