Mondo Description An autosomal recessive form of rickets caused by inactivating mutation(s) in the CYP2R1 gene, encoding vitamin D 25-hydroxylase, the hepatic enzyme that converts vitamin D to 25-hydroxyvitamin D, the precursor of 1,25-dihydroxyvitamin D (calcitriol). The condition is characterized by reduced serum concentrations of 25-hydroxyvitamin D, hypophosphatemia, hypocalcemia with secondary hyperparathyroidism and elevated serum alkaline phosphatase, and by failure to thrive, seizures, muscle weakness, and rickets.

Uniprot Description An autosomal recessive disorder caused by a selective deficiency of the active form of vitamin D (1,25-dihydroxyvitamin D3) and resulting in defective bone mineralization and clinical features of rickets. The patients sera have low calcium concentrations, low phosphate concentrations, elevated alkaline phosphatase activity and low levels of 25-hydroxyvitamin D.