Overhydrated stomatocytosis associated with a complex genotype including a novel mutation.

Overhydrated stomatocytosis is a rare autosomal dominant disorder known to cause variably severe haemolytic anaemia due to heterozygous mutations in the gene. We report a 26-year-old man with recurring jaundice, splenohepatomegaly and mild chronic haemolytic anaemia with significant stomatocytosis. Extensive haemolytic work-up including flow cytometry for eosin-5'-maleimide and CD47 expression levels was carried out. Targeted resequencing revealed two probably causative heterozygous mutations in (Leu336Ser and Ile149Met) and one heterozygous mutation in (Glu1046Lys) involvement was confirmed by decreased RhAG macrocomplex component indicated by the reduced CD47 expression on erythrocytes. analysis concordantly flagged :Leu336Ser and :Glu1046Lys as likely deleterious mutation, whereas :Ile149Met was reported as likely neutral by PROVEAN. Family screening by Sanger sequencing revealed :Leu336Ser in a mother and :Glu1046Lys in a father who were both asymptomatic, excluding them as causative dominant events, thus establishing :Ile149Met, novel mutation as probably causative. This case illustrates the importance of family screening in interpreting next-generation sequencing (NGS) data, as in silico analysis alone can be misleading. Erudite generation of diagnostic possibilities based on a thorough baseline clinical and laboratory work-up remains as important as ever, even as NGS brings about a paradigm shift in the diagnostic work-up of rare haemolytic anaemias.