Analysis of SLC25A13 gene mutations and prenatal diagnosis for 20 families affected with citrin deficiency

Objective To detect mutations of SLC25A13 gene in 20 families affected with citrin deficiency and provide prenatal diagnosis for them. Methods The 20 probands and their parents were subjected to high-frequency mutation screening combined with Sanger sequencing. After confirming the genotype of each pedigree, genetic counseling and prenatal diagnosis were performed for their subsequent pregnancies. Results Biallelic pathogenic mutations of the SLC25A13 gene were identified in all probands. These included three deletions (c.851del4, c. 1092_1095delT, and c. 495delA), two splice-site mutations (IVS6+ 5G>A and IVS11+ 1G>A), two nonsense mutations (c.775C>T (p.Q259X) and c. 72T>A (p.Y24X)), one duplication mutation (c.1638_1660dup), one insertion (IVSl6ins3kb), and one missense mutation (c.1775A>C (p.Q592P)). Among 24 fetuses undergoing prenatal diagnosis, 8 had normal genotypes, 11 were mutation carriers, while 5 harbored biallelic mutations. Those with wild type alleles or heterozygous SLC25A13 mutations were delivered. Two fetuses harboring homozygous c. 851del4 mutations were also delivered. Three fetuses harboring biallelic mutations were terminated. Conclusion Analysis of SLC25A13 gene mutations in families affected by citrin deficiency can provide evidence for molecular diagnosis and facilitate genetic counseling and prenatal diagnosis for the subsequent pregnancy, which can effectively reduce the risk of birth of further affected children. Key words: Citrin deficiency; SLC25A13 gene; Mutation; Prenatal diagnosis