A case of vitamin D hydroxylation-deficient rickets type 1A caused by 2 novel pathogenic variants in CYP27B1 gene
10.6065/apem.2019.24.2.137
- Author:
You Min KIM
1
;
Yoon Young JANG
;
Ji Eun JEONG
;
Hye Jin PARK
;
Ja Hyun JANG
;
Jin Kyung KIM
Author Information
1. Department of Pediatrics, Catholic University of Daegu School of Medicine, Daegu, Korea. kimjk@cu.ac.kr
- Publication Type:Case Report
- Keywords:
Vitamin D hydroxylation-deficient rickets type1A;
CYP27B1;
Hypocalcemia
- MeSH:
25-Hydroxyvitamin D3 1-alpha-Hydroxylase;
Alkaline Phosphatase;
Calcitriol;
Calcium Carbonate;
Databases, Genetic;
Fathers;
Humans;
Hypocalcemia;
Infant;
Mothers;
Rickets;
Vitamin D;
Vitamins;
Weights and Measures
- From:Annals of Pediatric Endocrinology & Metabolism
2019;24(2):137-141
- CountryRepublic of Korea
- Language:English
-
Abstract:
Vitamin D hydroxylation-deficient rickets type 1A (VDDR1A, OMIM 264700) is a rare autosomal recessive inherited disorder. Pathogenic variants in the CYP27B1 gene lead to loss of 1α-hydroxylase activity. We report the case of a 22-month-old toddler who presented with growth retardation and delayed development. The patient exhibited the typical laboratory findings of VDDR1A, including hypocalcemia (calcium: 5.2 mg/dL), elevated serum level of alkaline phosphatase (2,600 U/L), elevated serum level of intact-parathyroid hormone (238 pg/mL), low 1,25(OH)₂D₃ level (11.2 pg/mL), and normal 25(OH)D₃ level (40.7 ng/mL). His height and weight were 76.5 cm and 9.5 kg, respectively (both <3rd percentile). The Bayley Scales of Infant and Toddler Development II indicated significantly delayed development (mental development index <50, psychomotor development index <50). The patient was a compound heterozygous for two novel pathogenic variants in the CYP27B1 gene: c.57_69del (p.Glu20Profs*2) and c.171dupG (p.Leu58Alafs*275), inherited from his mother and father, respectively. The patient showed remarkable improvement after treatment with calcitriol and calcium carbonate.
