Genomic structure of the adult-onset type II citrullinemia gene, SLC25A13, and cloning and expression of its mouse homologue

Abstract

Citrullinemia is an autosomal recessive disease characterized by an argininosuccinate synthetase (ASS) deficiency. Adult-onset type II citrullinemia (CTLN2) is a form of the disease that is defined by a quantitative decrease in ASS protein, but with normal kinetic properties. The gene causing CTLN2 (SLC25A13) was identified by positional cloning (from 7q21.3) and found to encode a putative calcium-dependent mitochondrial carrier protein. To facilitate mutation analysis, here we describe the intron-exon boundaries of the human SLC25A13 gene. We have also cloned and characterized the mouse homologue (Slc25a13), which is predicted to encode a protein of 676 amino acids with 96% amino acid identity to SLC25A13. RNA in situ hybridization analysis shows that Slc25a13 is expressed in the branchial arches, as well as the limb and tail buds, during mouse embryonic development (E10.5). At E13.5 expression of Slc25a13 is most predominant in epithelial structures, in addition to the forebrain, kidney, and liver.