ASSOCIATION OF COMPLEMENTFACTOR H GENE (CFH) SINGLE NUCLEOTIDE POLYMORPHISM WITH RECURRENT APHTHUS STOMATITIS

Abstract

Background: Recurrent aphthous stomatitis (RAS) is a common chronic inflammation affecting oral mucosa that lead to mucosal ulceration. The causes are unclear, but dysregulation of the immune response has been proposed to be implicated in the development of the disease. In this study, we hypothesized that RAS is provoked by the dysregulation of the complement system, through the impairment of the function of complement regulatory proteins, the present study has aimed to investigate the impact of CFH gene SNPs that encodes the production of complement factor H in RAS development. Subject and Methods: Blood samples from 46 patientswith recurrent aphthus stomatitis were collected including 35 males and 11 females and 46 age and sex matched apparently healthy (with healthy oral cavity) volunteersincluding 23 males and 23 females were involved as a control group. Gnomic DNA was extractedfrom each blood sampleusing the isopropanol/ethanol method. Specific primers were used to amplify the CFH gene fragment that harbors the rs1061170 site encoding theTyr402 aminoacid. The PCR products were digested with NlaIII restriction enzyme. Results: A significant difference was found between the age groups among the RAS patients in regard to the severity of and recurrence of the RAS episodes, it was found to be higher significantly among the age group (20-30 years) compared to other age groups among RAS patients. Out of the 46 RAS patients, the CFH single nucleotide polymorphism (SNP), Tyr402His polymorphism variant was detected in 18 (39.1%); 11 (23.9%) females and 7 (15.2%) males, represented as 8 (17.4%) Tyr/His heterozygous variants and 10 (21.7%) were His/His homozygous variant. Among the 46 healthy control group, the CFH single nucleotide polymorphism (SNP), (Tyr402His polymorphism variant) was detected in 6 (13%) all of them were Tyr402His variant, 2 (4.3%) males and 4 (8.7%) females. There was a significant difference in the CFH (Tyr/His, His/His) variants rates between the RAS group and the healthy control group (p <0.05), but there was no significant difference of CFH (Tyr/His, His/His) variants rates between the males and females in the RAS group. Conclusions: We suggest that Tyr402Hispolymorphism can be considered as a risk factor for the RAS development, and His204His variant is more associated with the disease, however, more studies are recommended to be conducted on a larger sample size to confirm these evidences. Duhok Med J 2017; 11 (2): 84-95.