Related Experiment Video
Updated: Apr 24, 2026

Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease
Published on: April 4, 2018
Association Between Vitamin D Levels and Vitamin D Receptor (VDR) Gene Polymorphisms in Nepalese Population
Sujata Baidya1, Pratibha Kandel1, Smrity Rajkarnikar1
1Department of Clinical Biochemistry, Institute of Medicine, Maharajgunj Medical Campus, Tribhuvan University, Maharajgunj, Kathmandu, Nepal.
Background:
Vitamin D deficiency is a global public health concern. Small variations in the proteins involved in vitamin D metabolism affect levels and physiological roles of vitamin D. However, there is a paucity of data regarding such factors in our population. This study was designed to assess the distribution of polymorphisms of vitamin D Receptor (VDR) gene (rs2238136 and rs731236) in vitamin-D deficient Nepalese population.
Methods:
A total of 400 apparently healthy individuals visiting our center were enrolled. Five ml of blood was collected in gel vial and EDTA vial. The 25(OH)D levels were estimated in ABBOTT Architect autoanalyzer. After extracting genomic DNA, the VDR gene polymorphism (rs2238136 and rs731236) was analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The amplified products, 135 bp and 716 bp were digested using restriction enzymes Bpu10IA and TaqI for rs2238136 and rs731236, respectively, electrophoresed on 2% agarose gel and visualized under UV illuminator. Statistical analysis was done using SPSS version 21.0.
Results:
The distribution of both rs2238136 and rs731236 followed Hardy-Weinberg equilibrium. There were 24 AA, 238 GG, and 138 AG genotypes found in rs2238136, whereas 226 TT, 34 CC, and 140 TC genotypes were found in rs731236. In contrast to rs731236, vitamin D levels varied among genotypes of rs2238136.
Conclusions:
In our population, there was a higher prevalence of GG genotype (rs2238136) and TT genotype (rs731236). Increased prevalence of vitamin D deficiency in our region may be due to these genetic variations.
Related Concept Videos
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Principles of Pharmacogenetics: Types of Genetic Variants
Single Nucleotide Polymorphisms-SNPs
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin...

