Siblings with Ethylmalonic encephalopathy: Case Report

Deficiency of mitochondrial sulfur dioxygenase (ETHE1) causes a rare inborn errors of metabolism, ethylmalonic encephalopathy, which is characterized by early-onset encephalopathy, chronic hemorrhagic diarrhea, recurrent petechiae, orthostatic acrocyanosis, death in the first years of life and defective cytochrome C oxidase because of hydrogen sulfide accumulation. Biochemical hallmarks of the disease are high level of lactate, and C4-C5-acylcarnitines in blood, markedly elevated urinary excretion of methylsuccinic and ethylmalonic (EMA) acids. We report two siblings who admitted to pediatric metabolic unit with acrocyanosis, chronic diarrhea and psychomotor retardation later diagnosed as ethylmalonic encephalopathy. Molecular analyses revealed a homozygous for p. R163Q(c.488 G>A) mutation in ETHE1 gene.