NDUFA13 and hypertrophic cardiomyopathy: Previously, biallelic NDUFA13 variants were initially reported in two sisters with early onset hypotonia, dyskinesia and optic neuropathy3 and subsequently in a single case with Leigh syndrome associated with mild hypertrophic cardiomyopathy and progressive spastic tetraparesis.4 One patient in the NDUFA13 cohort described by Kaiyrzhanov et al. presented with skeletal dysplasia and glaucoma.