Genetic polymorphism of Fcγ-receptors IIa, IIIa and IIIb in South Indian patients with generalized aggressive periodontitis.

Recent evidence suggests that polymorphisms in Fcγ receptors are associated with different forms of periodontitis. However, the FcγR genotypes and their allele frequency differ among subjects from different ethnic backgrounds. The aim of the present study was to determine whether specific FcγRIIa, FcγRIIIa, and FcγRIIIb alleles and/or genotypes are associated with susceptibility to generalized aggressive periodontitits (GAgP) in a South Indian population. Buccal scrapings were obtained from 60 subjects with GAgP and 60 periodontally healthy individuals, and DNA was extracted from each of the samples. FcγRIIa and FcγRIIIa genotyping was performed by polymerase chain reaction (PCR) amplification of DNA with allele-specific primers followed by allele-specific restriction digestion of the products, whereas FcγRIIIb genotyping was done by allele-specific PCR. There was no significant difference in the distribution of the FcγRIIa H/R genotype between GAgP patients and healthy subjects, although significant over-representation of the R allele was noted in GAgP patients. With regard to FcγRIIIa F/V genetic polymorphism, the homozygous V/V genotype and V allele were significantly over-represented in the GAgP group, whereas the F/F genotype and F allele were over-represented in the controls. Furthermore, there was significant over-representation of the FcγRIIIb-NA2 allele and NA2/NA2 genotype in GAgP patients, and of the NA1/NA1 genotype and NA1 allele in the controls. These data suggest that the FcγRIIIa V/V genotype and/or V allele, as well as the FcγRIIIb NA2/NA2 and/or NA2 allele, along with the FcγRIIa- R allele, may be risk factors for GAgP in the population of South India.