Beta-defensin 1 gene polymorphisms at 5' untranslated region are not associated with a susceptibility to recurrent aphthous stomatitis.

OBJECTIVE: The purpose of this study was to evaluate the possible association between two single nucleotide polymorphisms of the beta-defensin 1 gene: -20 G > A and -44 C > G at 5 untranslated region and recurrent aphthous stomatitis in a cohort of Polish patients. DESIGN: One hundred and six patients suffering from recurrent aphthous stomatitis and 96 healthy volunteers were genotyped at beta-defensin 1-20 G > A and -44 C > G using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach. The results were statistically analysed with the difference test between two proportion and chi-square tests with p < 0.05 as a significance level (Dell Statistica data analysis software system, version 13, Dell Inc. 2016). RESULTS: No statistically significant differences between the tested groups were revealed in the genotype distribution for -20 G > A and -44 C > G polymorphisms of the beta-defensin 1 gene. Stratification into carriers and non-carriers of alleles did not unequivocally show the single nucleotide polymorphism recognized as a risk factor for recurrent aphthous stomatitis. However, after gender stratification, statistically significant differences in the distribution of some DEFB1 genotypes were observed. Heterozygotes of G[-20]A and C[-44]G genotypes were found more frequently in males with RAS than in males from the control group. Moreover, a significantly higher rate of carriers of the polymorphic *A[-20] allele was found in males with RAS compared to the controls. CONCLUSIONS: The role of the tested single nucleotide polymorphisms of the beta-defensin 1 gene in the aetiology of recurrent aphthous stomatitis has not been confirmed. Further observations are required to clarify this potential association.