Presence of a Deletion Mutation (c.716delA) in the Ligand Binding Domain of the Vitamin D Receptor in an Indian Patient with Vitamin D-Dependent Rickets Type II

The document described a case of Vitamin D-dependent rickets type II in an Indian patient with severe alopecia and rickets, caused by a homozygous deletion mutation (c.716delA) in the ligand binding domain of the vitamin D receptor gene. This mutation resulted in a frameshift and premature termination of the VDR protein, leading to a complete loss of its ligand binding domain and reduced binding with VDR response elements. The patient showed significant clinical improvements over 18 months with high-dose calcium infusion and oral phosphate treatment. The study highlighted the genetic basis of the condition and the importance of genetic testing for accurate diagnosis and management. The research was supported by the Indian Council of Medical Research and involved contributions from multiple authors affiliated with the All India Institute of Medical Sciences, New Delhi.