2. Academic Validation
  3. CYP3A4 mutation causes vitamin D-dependent rickets type 3

CYP3A4 mutation causes vitamin D-dependent rickets type 3

  • J Clin Invest. 2018 May 1;128(5):1913-1918. doi: 10.1172/JCI98680.
Jeffrey D Roizen 1,  Dong Li 2,  Lauren O'Lear 1,  Muhammad K Javaid 3,  Nicholas J Shaw 4,  Peter R Ebeling 5,  Hanh H Nguyen 5,  Christine P Rodda 6,  Kenneth E Thummel 7,  Tom D Thacher 8,  Hakon Hakonarson 2,  Michael A Levine 1
Affiliations

Affiliations

  • 1 Division of Endocrinology and Diabetes and.
  • 2 Center for Applied Genomics, The Children's Hospital of Philadelphia (CHOP), University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
  • 3 Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom.
  • 4 Department of Endocrinology and Diabetes, Birmingham Children's Hospital and Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.
  • 5 Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia.
  • 6 Australian Institute for Musculoskeletal Science, Sunshine Hospital, and Department of Paediatrics, University of Melbourne,Parkville, Victoria, Australia.
  • 7 Department of Pharmaceutics, University of Washington, Seattle, Washington, USA.
  • 8 Department of Family Medicine, Mayo Clinic, Rochester, Minnesota, USA.
PMID: 29461981 DOI: 10.1172/JCI98680
Abstract

Genetic forms of vitamin D-dependent rickets (VDDRs) are due to mutations impairing activation of vitamin D or decreasing vitamin D receptor responsiveness. Here we describe two unrelated patients with early-onset rickets, reduced serum levels of the vitamin D metabolites 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and deficient responsiveness to parent and activated forms of vitamin D. Neither patient had a mutation in any genes known to cause VDDR; however, using whole exome sequencing analysis, we identified a recurrent de novo missense mutation, c.902T>C (p.I301T), in CYP3A4 in both subjects that alters the conformation of substrate recognition site 4 (SRS-4). In vitro, the mutant CYP3A4 oxidized 1,25-dihydroxyvitamin D with 10-fold greater activity than WT CYP3A4 and 2-fold greater activity than CYP24A1, the principal inactivator of vitamin D metabolites. As CYP3A4 mutations have not previously been linked to rickets, these findings provide insight into vitamin D metabolism and demonstrate that accelerated inactivation of vitamin D metabolites represents a mechanism for vitamin D deficiency.

Keywords

Bone Biology; Bone disease; Genetic diseases; Genetics.

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