Abstract
Purpose:
To determine whether genetic variations altering the function or expression of TNFA, contribute to the pathogenesis of dry eye disease.
Methods:
Genomic DNA was extracted from blood samples of unrelated dry eye disease patients (non-Sjogren’s syndrome patients (n=200) and Sjogren’s syndrome patients (n=100)). Polymerase chain reaction and direct sequencing were used to screen variations in promoter region of TNFA gene. One hundred fifty control individuals without corneal disease were selected from the general population.
Results:
We investigated 6 SNPs of TNFA; -1196 C>T, -1031 T>C, -863 C>A, -857C>T, -308 G>A (rs1800629) and -238 A>G (rs361525) in promoter. Among them, -1196 C>T, -857 C>T, rs1800629 and rs361525 were different between patient groups and control groups. The *A allele frequency of rs361525 in dry eye patients (2.6%) and Sjogrens’ patients (2.5%) were decreased compared with control subjects (5.1%). The *A allele frequency of rs1800629 was lower in Sjogrens’ patients (2.5%) than in the controls (4.8%). In -1196C>T variation, *T allele of both patient groups was decreased compared with control subjects. Whereas, the *T Allele frequency of -857 C>T was higher in the Sjogrens’ patients (30.0%) than in the controls (16.8%). The genotype distributions of all polymorphisms of TNFA among the control subjects and the affected individuals were in Hardy-Weinberg equilibrium.
Conclusions:
The genetic variations of TNFA gene seem to be associated with dry eye predisposition in Korean populations.
Keywords: 539 genetics •
486 cornea: tears/tear film/dry eye