Expanding the clinical spectrum of mitochondrial citrate carrier (SLC25A1) deficiency: Facial dysmorphism in siblings with epileptic encephalopathy and combined D,l-2-hydroxyglutaric aciduria

Abstract

Recessive mutations in SLC25A1 encoding mitochondrial citrate carrier cause a rare inherited metabolic disorder, combined D,L-2-hydroxyglutaric aciduria (D,L-2-HGA), characterized by epileptic encephalopathy, respiratory insufficiency, developmental arrest and early death. Here, we describe two siblings compound heterozygotes for null/missense SLC25A1 mutations, c.18_24dup (p.Ala9Profs*82), and c.134C>T (p.Pro45Leu). These children presented with classic clinical features of D,L-2-HGA, but also showed marked facial dysmorphism. Additionally, there was prominent lactic acidosis in one of the siblings. Our observations suggest that facial dysmorphism is a previously unrecognized but an important diagnostic feature of SLC25A1 deficiency and expand the clinical phenotype linked to SLC25A1 mutations.