Identification of variants in 94 Chinese patients with hereditary spherocytosis by next-generation sequencing

Hereditary spherocytosis (HS) is the most common type of hereditary erythrocyte membrane disease and has varied phenotypic features and genetic patterns. We herein performed a retrospective study of 94 patients with HS and aimed to investigate the genetic variations and genotype-phenotype correlations using targeted next-generation sequencing. In 79/94 (84%) patients, 83 HS variants including 67 novel variants were identified. Pathogenic variants of SPTB, ANK1, SLC4A1, SPTA1, and EPB42 were found in 32/79(41%), 22/79(28%), 15/79 (19%), 8/79 (9%), and 3/79 (4%) of the patients respectively, revealing that SPTB is the most frequently mutated HS gene in Eastern China. Most SPTB and ANK1 gene variations were nonsense and frameshift variations. Missense variants were the main variant type of SLC4A1, SPTA1, and EPB42 genes. Interestingly, one SPTA1 variant (p. Arg1757Cys) showed an autosomal dominant inheritance pattern and one EPB42 variant (p. Gln377His) was apparent as a hotspot variation. Furthermore, genotype-phenotype analysis was performed among the five mutated gene groups. Besides the finding that patients with the SLC4A1 variant had the highest mean corpuscular hemoglobin levels, no clear correlations between genotype and phenotype were observed.