Pseudovitamin D deficiency rickets--a report from the Indian subcontinent.

Pseudovitamin D deficiency rickets (also called vitamin D dependent rickets type I) is one of the types of inherited rickets and is caused by a deficit in renal 25-hydroxyvitamin D 1alpha-hydroxylase. This form of rickets has not been reported from the Indian subcontinent. Three patients with this disorder are presented. These patients were all females aged 3-20 years and presented with growth failure and skeletal deformities. All had florid clinical and radiological rickets. The biochemical abnormalities seen included hypocalcaemia, hypophosphataemia, and hyperphosphatasia. All patients had grossly raised 25-hydroxyvitamin D concentrations and markedly low to undetectable concentrations of 1,25-dihydroxyvitamin D. A disturbing feature of this study was the late referral of the patients.