Abstract
The PHEX gene (phosphate-regulating gene with homologies to endopeptidase on the X chromosome) was identified in 1995 as the mutated gene in patients with a prevalent form (1: 20.000) of hereditary human ricket, called XLH (X-linked hypophosphataemia ). The XLH is characterized by defects in the reabsorption of phosphate and vitamin D metabolism, and disorders such as rickets, osteomalaci…