Hereditary Hemolytic Anemia Due to PIEZO1 Red Blood Cell Membrane Defect.

PIEZO1 (piezo-type mechanosensitive ion channel component 1) is a mechanosensitive ion channel protein. Gain-of-function variants in the PIEZO1 gene are known to cause dehydrated hereditary stomatocytosis (DHS) also termed hereditary xerocytosis. This is a rare autosomal dominant condition characterized by variable-degree anemia with a tendency toward hemolysis, erythrocyte dehydration and iron overload. While the diagnostic workflow for DHS is well-established, diagnosis is often delayed due to overlapping clinical features with other hemolytic anemias and the pleiotropic effects of PIEZO1 variants. We describe the case of a Greek patient with a compensating hemolysis since birth. DHS diagnosis was established only after a prolonged history of repeated investigations spanning from his early life to 70 years of age, when a conclusive testing was achieved.