Hereditary xerocytosis is a dominant red blood cell membrane disorder characterized by an increased leakage of potassium from the interior to the exterior of the red blood cell membrane, leading to water loss, red cell dehydration, and chronic hemolysis. In 90% of cases, it is associated with heterozygous gain-of-function mutations in PIEZO1, a gene that encodes a mechanotransducer responsible for converting mechanical stimuli into biological signals. The remaining 10% of cases are linked to mutations in the GARDOS channel gene.