Single Nucleotide Polymorphisms in the BDNF, VDR, and DNASE 1 Genes in Dry Eye Disease Patients: A Case-Control Study

Area of Science:

• Genetics
• Ophthalmology
• Psychiatry

Background:

• Dry eye disease (DED) is a multifactorial condition affecting ocular surface health.
• Genetic factors are increasingly recognized for their role in complex diseases like DED.
• The interplay between genetic predisposition and comorbid conditions such as depression warrants investigation in DED.

Purpose of the Study:

• To investigate potential associations between single nucleotide polymorphisms (SNPs) in the brain-derived neurotrophic factor (BDNF), vitamin D receptor (VDR), and DNASE1 genes and dry eye disease (DED).
• To explore whether any identified SNP-DED associations are modified by the presence of depression.

Main Methods:

• A case-control study involving 64 DED patients and 51 controls.
• Saliva samples were collected for genotyping of 12 hypothesized SNPs using TaqMan assays.
• Allele and genotype frequencies were compared between groups, and odds ratios were calculated. Stratified analyses examined the influence of depression status.

Main Results:

• The minor allele A of the Val66Met (rs6265) SNP in the BDNF gene was more frequent in DED cases (18%) than controls (9%) (P=0.05), with an odds ratio of 2.22.
• Two VDR gene SNPs, Fokl (rs2228570) and Apal (rs7975232), showed higher minor allele A frequencies in DED cases (ORs 1.72 and 1.66, respectively; P=0.06).
• Although not statistically significant, DED cases with depression exhibited a 3.93 times higher likelihood of carrying the minor allele A of the BDNF Val66Met SNP compared to controls.

Conclusions:

• This pilot study suggests potential associations between the BDNF Val66Met SNP and VDR Fokl and Apal SNPs with DED.
• The findings indicate that the association between DED and the BDNF Val66Met SNP may be influenced by depression status.
• Further research with larger cohorts is needed to confirm these preliminary genetic associations in DED.