Hereditary vitamin D resistant rickets caused by a novel mutation in the vitamin D receptor that results in decreased affinity for hormone and cellular hyporesponsiveness - PubMed (original) (raw)

Case Reports

. 1997 Jan 15;99(2):297-304.

doi: 10.1172/JCI119158.

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Case Reports

Hereditary vitamin D resistant rickets caused by a novel mutation in the vitamin D receptor that results in decreased affinity for hormone and cellular hyporesponsiveness

P J Malloy et al. J Clin Invest. 1997.

Abstract

Mutations in the vitamin D receptor (VDR) result in target organ resistance to 1alpha,25-dihydroxyvitamin D [1,25(OH)2D3], the active form of vitamin D, and cause hereditary 1,25-dihydroxyvitamin D resistant rickets (HVDRR). We analyzed the VDR of a patient who exhibited three genetic diseases: HVDRR, congenital total lipodystrophy, and persistent mullerian duct syndrome. The patient was treated with extremely high dose calcitriol (12.5 microg/d) which normalized serum calcium and improved his rickets. Analysis of [3H]1,25(OH)2D3 binding in the patient's cultured fibroblasts showed normal abundance of VDR with only a slight decrease in binding affinity compared to normal fibroblasts when measured at 0 degrees C. The patient's fibroblasts demonstrated 1,25(OH)2D3-induction of 24-hydroxylase mRNA, but the effective dose was approximately fivefold higher than in control cells. Sequence analysis of the patient's VDR gene uncovered a single point mutation, H305Q. The recreated mutant VDR was transfected into COS-7 cells where it was 5 to 10-fold less responsive to 1,25(OH)2D3 in gene transactivation. The mutant VDR had an eightfold lower affinity for [3H]1,25(OH)2D3 than the normal VDR when measured at 24 degrees C. RFLP demonstrated that the patient was homozygous for the mutation while the parents were heterozygous. In conclusion, we describe a new ligand binding domain mutation in the VDR that causes HVDRR due to decreased affinity for 1,25(OH)2D3 which can be effectively treated with extremely high doses of hormone.

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References

    1. Biochem J. 1994 Oct 1;303 ( Pt 1):255-62 - PubMed
    1. J Clin Endocrinol Metab. 1994 Feb;78(2):313-6 - PubMed
    1. Nature. 1995 Dec 14;378(6558):681-9 - PubMed
    1. Nature. 1995 Dec 14;378(6558):690-7 - PubMed
    1. Cell. 1995 Dec 15;83(6):841-50 - PubMed

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