An unusual presentation of vitamin D dependent rickets type 2 with low 25 (OH) D3 levels and alopecia: a case report of two siblings

Abstract

Vitamin D-dependent rickets type 2 (VDDR2) is a rare autosomal recessive (AR) disorder caused either by a mutation in the Vitamin D receptor gene or overexpression of the binding protein leading to end-organ resistance to 1,25 (OH)2 vitamin D3 or defective hormonal actions respectively. It clinically represents growth retardation presenting in the 1st year of life and is frequently associated with alopecia totalis and markedly elevated levels of 1, 25(OH)2 D, which differentiates it from VDDR type 1. We hereby report siblings of a family, who presented with clinical, radiological features of rickets and alopecia totalis. To our knowledge, only a few cases have been reported in literature describing the AR-pattern and low 25(OH)D3 levels in VDDR2.