SLC25A13 and hyperinsulinemic hypoglycemia, familial, 4: Citrin, an aspartate glutamate carrier in the mitochondrial inner membrane, plays a role in the supply of aspartate from the mitochondria to the cytosol and malate aspartate nicotinamide adenine dinucleotide hydrogen shuttle.[1] Citrin deficiency is an autosomal recessive disorder caused by mutations in the SLC25A13 gene on chromosome 7q21.3.