NDUFS4‐related LS, while characterised by neurological dysfunction, demonstrates significant cardiac involvement with hypertrophic cardiomyopathy documented (Table S1) in approximately 25% (8 of 32) of described cases [1, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37]. This evidence concerns the gene NDUFS4 and Leigh syndrome.