However, on molecular testing, it was revealed that the patient was harboring pathogenic variants of the CYP27B1 gene, in a compound heterozygous manner, with a novel missense mutation in exon 6 of the CYP27B1 gene, c.1136G > C (p.Arg379Thr), suggesting the diagnosis of vitamin D-dependent rickets type 1A. The gene discussed is CYP27B1; the disease is vitamin D-dependent rickets, type 1A.