Child Kidney Dis.  2019 Oct;23(2):111-115. 10.3339/jkspn.2019.23.2.111.

Vitamin D Dependent Rickets Type 1A Caused by CYP27B1 Mutation

• Bak NR
• Song ES
• Yang EM
• Kim CJ

• KMID: 2464936
• DOI: http://doi.org/10.3339/jkspn.2019.23.2.111

Abstract

Vitamin D dependent rickets type 1A (VDDR1A) is an autosomal recessive disorder caused by mutations in CYP27B1 . Clinical findings are growth retardation, hypotonia, muscle weakness, hypocalcemic seizures, and radiological features of rickets. We aimed to present the VDDR1A case with a genetic study of CYP27B1 . The 14-month-old boy was admitted to the hospital due to a seizure. Serum calcium, phosphorus, alkaline phosphatase, parathyroid hormone (PTH), 25(OH) vitamin D, and 1,25(OH)2 vitamin D values were 5.1 mg/dL, 3.7 mg/dL, 705 IU/L, 429 pg/mL, 24.9 ng/mL, and 8.8 pg/mL, respectively. Radiological study showed cupping and fraying of the distal ulna and radius. The molecular genetic study revealed that the patient had a compound heterozygous mutation, Phe443Profs*24 and c.589+1G>A, in CYP27B1 . Genetic analysis of the family members presented that the mother was heterozygous for the mutation c.589+1G>A, and that the father was heterozygous for Phe443Profs*24. The patient was treated with calcium lactate and calcitriol. Until now, six Korean patients with VDDR1A have been studied. Including this case, Korean patients with VDDR1A were found to have only three different mutations in 14 alleles, indicating that the mutation in the CYP27B1 gene is homogeneous in the Korean population.

Keyword

Rickets; CYP27B1 gene; Vitamin D dependent rickets type 1A

MeSH Terms

25-Hydroxyvitamin D3 1-alpha-Hydroxylase*
Alkaline Phosphatase
Alleles
Calcitriol
Calcium
Fathers
Humans
Infant
Lactic Acid
Male
Molecular Biology
Mothers
Muscle Hypotonia
Parathyroid Hormone
Phosphorus
Radius
Rickets*
Seizures
Ulna
Vitamin D*
Vitamins*
25-Hydroxyvitamin D3 1-alpha-Hydroxylase
Alkaline Phosphatase
Calcitriol
Calcium
Lactic Acid
Parathyroid Hormone
Phosphorus
Vitamin D
Vitamins