Based on the patient’s clinical presentation, Leigh syndrome was suspected and Whole Exome Sequencing (WES) was performed at 14 years of age, revealing a homozygous, previously reported [8], pathogenic variant in NDUFA13 (NM_015965.7(NDUFA13): c.170G>A (p.(Arg57His)). The gene discussed is NDUFA13; the disease is Leigh syndrome.