A novel pathogenic mutation of the CYP27B1 gene in a patient with vitamin D-dependent rickets type 1: a case report

Table 3 Full exome-sequencing results of the patient

Variant filtering based on inheritance model, clinical and bioinformatics analysis
	Post-inheritance model filtering	Post-alteration review	Post-medical review			Candidate genes
		Total	Post-clinical associated review
			Characterized	Clinically novel	Total
Autosomal dominant genes (alterations)	12(13)	2(2)	0(0)	1(1)	1(1)	0(0)
Autosomal recessive genes (alterations)	41 (57)	32(45)	1(1)	23(34)	24(35)	1(1)
X-linked recessive genes (alterations)	0(0)	0(0)	0(0)	0(0)	0(0)	0(0)
X-linked dominant genes (alterations)	0(0)	0(0)	0(0)	0(0)	0(0)	0(0)
Y-linked genes (alterations)	N/A	N/A	N/A	N/A	N/A	N/A
Total genes (alterations)	53(70)	34(47)	1(1)	24(35)	25(36)	1*(1)

*The candidate gene in this patient is CYP27B1 gene, which is located in chromosome 12q13.3 and encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases, which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. The protein encoded by this gene localizes to inner mitochondrial membrane where it hydroxylates 25-hydroxyvitamin D3 at the 1 alpha position. This reaction synthesizes 1, 25 dihydroxyvitamin D3, which binds to vitamin D receptor and regulates calcium metabolism. Thus this enzyme regulates the level of biologically active vitamin D and plays a major role in calcium homeostasis. Mutations in this gene can result in vitamin D dependent rickets type 1.

ISSN: 1756-0500