Screening of interleukin 17F gene polymorphisms and eight subgingival pathogens in chronic periodontitis in Libyan patients.

Chronic periodontitis (CP) is triggered by periodontal pathogens influenced by genetic and environmental factors. Recent studies have suggested that anti-inflammatory cytokines such as interleukin 17 (IL-17) play a prominent role in the pathogenesis of CP. This study aimed to investigate the association between eight sub-gingival pathogens and interleukin 17F (IL-17F) gene single nucleotide polymorphisms with CP among Libyans. A case-control study was conducted on 100 individuals between the ages of 25-65 years. Species-specific 16S rRNA primers for each pathogen were used in a multiplex PCR reaction to detect sub-gingival pathogens from a paper point sample. DNA was also extracted from buccal swab samples and IL-17F polymorphisms were detected by Sanger sequencing. A highly significant association between the seven sub-gingival pathogens and CP, (p-value 0.0001) and a high prevalence of (100%), (96%), and (92%), (82%), (74%), (72%), (40%) were found in the case group compared with control group. A novel variant in the c. *34 G>A in IL-17F gene caused a change in glutamic amino acid to lysine amino acid, position on chromosome number (6) in the third exon, mRNA/genomic position 597, found in 14.6% of CP patients (p-value = 0.010) while the IL-17F (rs763780) SNP showed no association with CP (p-value = 0.334). P. intermedia appear as keystone pathogen for CP in the Libyan population. A novel variant in the IL-7F gene may be related to the severity of CP.