Mutation analysis of Chinese sporadic congenital sideroblastic anemia by targeted capture sequencing

Wenbin An, Jingliao Zhang, Lixian Chang, Yingchi Zhang, Yang Wan, Yuanyuan Ren, Deyun Niu, Jian Wu, Xiaofan Zhu, Ye Guo

Congenital sideroblastic anemias (CSAs) comprise a group of heterogenous genetic diseases that are caused by the mutation of various genes involved in heme biosynthesis, iron-sulfur cluster biogenesis, or mitochondrial solute transport or metabolism. However, approximately 40 % of patients with CSA have not been found to have pathogenic gene mutations. In this study, we systematically analyzed the mutation profile in 10 Chinese patients with sporadic CSA. We performed targeted deep sequencing analysis in ten patients with CSA using a panel of 417 genes that included known CSA-related genes. Mitochondrial genomes were analyzed using next-generation sequencing with a mitochondria enrichment kit and the HiSeq2000 sequencing platform. The results were confirmed by Sanger sequencing. The ALAS2 mutation was detected in one patient. SLC25A38 mutations were detected in three patients, including three novel mutations. Mitochondrial DNA deletions were detected in two patients. No disease-causing mutations were detected in four patients. To our knowledge, the pyridoxine-effective mutation C471Y of ALAS2, the compound heterozygous mutation W87X, I143Pfs146X, and the homozygous mutation R134C of SLC25A38 were found for the first time. Our findings add to the number of reported cases of this rare disease and to the CSA pathogenic mutation database. Our findings expand the phenotypic profile of mitochondrial DNA deletion mutations. This work also demonstrates the application of a congenital blood disease assay and targeted capture sequencing for the genetic screening analysis and diagnosis of heterogenous genetic CSA.