Identification of a novel ANK1 gene variant c.1504-9G>A and its mechanism of intron retention in hereditary spherocytosis.

Objective

The objective of this study was to pinpoint pathogenic genes and assess the mutagenic pathogenicity in two pediatric patients with hereditary spherocytosis.

Methods

We utilized whole-exome sequencing (WES) for individual analysis (case 1) and family-based trio analysis (case 2). The significance of the intronic mutation was validated through a Minigene splicing assay and supported by subsequent in vitro experiments.

Results

Both probands received a diagnosis of hereditary spherocytosis. WES identified a novel ANK1 c.1504-9G>A mutation in both patients, causing the retention of seven nucleotides at the 5' end of intron 13, as substantiated by the Minigene assay. This variant results in a premature stop codon and the production of a truncated protein. In vitro studies indicated a reduced expression of the ANK1 gene.

Conclusion

The novel ANK1 c.1504-9G>A variant is established as the causative factor for hereditary spherocytosis, with the c.1504-9G site functioning as a splicing receptor.