Novel nonsense mutation p. Gln264Ter in the ANK1 confirms causative role for hereditary spherocytosis: a case report.

Abstract

Background: Hereditary spherocytosis (HS) is the most common haemolytic anaemia caused by congenital membrane defects of red blood cells. The name derives from the presence of spherical red blood cells in the peripheral blood. Clinical manifestations of HS are anaemia, haemolytic jaundice, and large spleen, and infection can worsen the condition, often with cholelithiasis. HS is mainly caused by abnormal functions of the products of six genes. Splenectomy is the main treatment for HS.

Case presentation: Half a day after birth, the proband exhibited HS-related symptoms, with progressive aggravation. Routine examination in the outpatient department showed an increase in white blood cells and a decrease in red blood cells. His mother had HS and a partial splenectomy. We suspected that the infant might also have HS. Genomic DNA samples were extracted from the three members of the HS trio pedigree, and genomic whole-exome sequencing (WES) was performed. The three DNA samples were amplified by polymerase chain reaction (PCR), followed by Sanger sequencing to identify mutation sites. A novel nonsense heterozygous mutation, c.790C > T (p. Gln264Ter), in the ANK1 gene, which causes premature termination of translation, was found in this Chinese family with autosomal dominant HS.

Conclusions: This de novo nonsense mutation can cause the onset of HS in early childhood, with severe symptoms. Expanding the ANK1 genotype mutation spectrum will lay a foundation for the further application of mutation screening in genetic counselling.