Rickets in the tropics: not always nutritional.

To cite: Singh P, Eske GS, Dhaneria M, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2013009786 DESCRIPTION Vitamin D-dependent rickets type I A 6-year-old girl belonging to the lower socioeconomic class of a Muslim community, product of consanguineous marriage presented in the paediatric outpatient department with a history of progressive bowing of limbs, recurrent chest infections requiring hospitalisations in the past and failure to thrive. Calorie and protein consumption was just one-third of the requirement. Family history of similar problems was present in the mother. The mother had frank rickets beginning at the age of 1 and progressively increasing with age. The mother was treated at a private clinic for her disease with 1,25-dihydroxycholecalciferol (Calcitriol). A clinical examination revealed florid manifestations of rickets (figure1 A–D). Investigations showed near normal 25-hydroxy vitamin D and a low concentration of 1,25-dihydroxyvitamin D supporting the diagnosis of vitamin D-dependent rickets type-I (VDDR-I; table 1 and figures 2 and 3). VDDR-I also called as pseudo-vitamin D deficiency rickets, is an autosomal recessive disorder occurring due to impaired activity of renal 25-hydroxyvitamin D 1α-hydroxylase associated with raised 25-hydroxyvitamin D concentrations and markedly low to undetectable concentrations of 1,25-dihydroxyvitamin D.