Heritability of major depressive disorder (MDD) is between 36 and 44%, suggesting that up to nearly half of the phenotypic variability is attributable to genes. A number of genetic polymorphisms have been shown to predispose certain individuals to depression. Of particular interest are the polymorphisms of the vitamin D receptor (VDR) gene. Although the VDR gene has been well characterized and a vast number of polymorphisms have been identified, the association between BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236) single-nucleotide polymorphisms (SNPs), together with their haplotypes, and MDD risk have yet to be established. We conducted a matched case–control study with a total of 600 participants comprising 300 major depressive disorder (MDD) cases and 300 controls matched by age, gender and ethnicity in a 1:1 ratio, in four public hospitals in Kuala Lumpur and Selangor. Three adjacent SNPs of the VDR gene—BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236)—were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Odds ratios and 95% confidence intervals (CIs) were obtained from conditional logistic regression using Stata 16. Linkage disequilibrium and haplotype association with MDD were analyzed using the online SNPStats program. None of the genotypes of the three SNPs was significantly associated with risk of developing MDD after adjusting for confounding factors. However, the TAC (BAt) haplotype was associated with increased odds of MDD (adjusted OR = 2.17, 95% CI = 1.30–3.61, p = 0.003) using CCT (baT) as reference haplotype. The findings suggest that the BsmI-ApaI-TaqI TAC (BAt) haplotype of the VDR gene increases susceptibility to MDD.

重度抑郁症 (MDD) 的遗传率在 36% 到 44% 之间，这表明高达近一半的表型变异可归因于基因。许多遗传多态性已被证明使某些个体易患抑郁症。特别令人感兴趣的是维生素 D 受体 (VDR) 基因的多态性。尽管 VDR 基因已被很好地表征并且已经鉴定了大量多态性，但Bsm I (rs1544410)、Apa I (rs7975232) 和Taq之间的关联I (rs731236) 单核苷酸多态性 (SNP) 及其单倍型和 MDD 风险尚未确定。我们在吉隆坡和雪兰莪的四家公立医院进行了一项匹配的病例对照研究，共有 600 名参与者包括 300 名重度抑郁症 (MDD) 病例和 300 名对照，按年龄、性别和种族按 1:1 的比例匹配。VDR 基因的三个相邻 SNP—— Bsm I (rs1544410)、Apa I (rs7975232) 和TaqI (rs731236)——使用聚合酶链反应限制性片段长度多态性 (PCR-RFLP) 进行基因分型。优势比和 95% 置信区间 (CI) 是使用 Stata 16 从条件逻辑回归中获得的。使用在线 SNPStats 程序分析连锁不平衡和与 MDD 的单倍型关联。在调整混杂因素后，三个 SNP 的基因型均与发生 MDD 的风险无显着相关。然而， 使用 CCT (baT) 作为参考单倍型，TAC (BAt) 单倍型与 MDD 的几率增加有关（调整后的 OR = 2.17，95% CI = 1.30–3.61，p = 0.003）。研究结果表明Bsm I- Apa I- TaqVDR 基因的 I TAC (BAt) 单倍型增加了对 MDD 的易感性。