hrp0086p1-p124 | Bone & Mineral Metabolism P1 | ESPE2016

Two French Families with Vitamin D Dependency Rickets Type 1B Harbor Homozygous Recessive Expression Of CYP2R1 Mutations L99P and G42_L46DEL INSR

Molin Arnaud , Feillet Francois , Demers Nick , Wiedemann Arnaud , Brennan S , Kaufmann Martin , Jones Glenville , Kottler Marie Laure

Vitamin D dependency rickets type 1B (VDDR-1B) is a rare condition classified as rickets due to inadequate 25-hydroxylation of vitamin D. In this study, we describe rickets and loss-of-function CYP2R1 mutations in 6/10 individuals tested from two unrelated families. Five patients in family 1 (F1) have homozygous L99P mutations; while one member of family 2 (F2) has novel homozygous mutations at G42_L46del insR. The mutations, as well as another variant M248I found in ...