Expansion of the prenatal phenotype of PIEZO1 variants

The PIEZO1 gene, also known as Piezo-Type Mechanosensitive Ion Channel Component 1, causes two genetically allelic conditions: autosomal dominant dehydrated hereditary stomatocytosis (DHS) and autosomal recessive generalized lymphatic dysplasia of Fotiou (GLDF). Both may result in non-immune hydrops fetalis (NIHF) due to PIEZO1’s role in development of the lymphatic vasculature system. However, they differ by the mechanism of disease, with gain-of-function variants in PIEZO1 leading to a DHS phenotype, and loss-of-function variants leading to GLDF.