Vitamin D-Dependent Rickets, Type 2a, also known as hvdrr, is related to hypocalcemic vitamin d-dependent rickets and nephrocalcinosis, and has symptoms including muscle weakness, bone pain and difficulty standing. An important gene associated with Vitamin D-Dependent Rickets, Type 2a is VDR (Vitamin D Receptor), and among its related pathways/superpathways are Metabolism of steroids and Vitamin D receptor pathway. The drugs Cholecalciferol and Antibodies, Monoclonal have been mentioned in the context of this disorder. Affiliated tissues include bone and cortex, and related phenotypes are hypophosphatemia and hyperparathyroidism