[Interleukin-1 family polymorphisms in aggressive periodontitis patients and their relatives].
OBJECTIVE
To study whether interleukin-1( IL-1 )genotype and/or alleles were associated with aggressive periodontitis (AgP) patients and their relatives.


METHODS
Sixty-six AgP nuclear families including 66 probands and their 114 relatives were recruited. All probands were diagnosed as AgP according to 1999 classification of periodontal diseases and conditions, the diagnoses of their relatives were using a system of assessment (including the current and retrospective diagnosis and reported case history). Anti-coagulated peripheral blood samples were collected from all of the 180 subjects, and DNA was extracted from each blood sample. Single nucleotide polymorphisms (SNPs) at IL-1A +4845 and IL-1B j 511 were analyzed by PCR-RFLP assay. The polymorphism of a variable number of tandem repeat (VNTR) in intron 2 of IL-1RN was detected by PCR amplification and fragment size analysis. The distributions of genotypes and/or alleles in all groups were analyzed by logistic regression analysis. Data were also analyzed using the family-based association test.


RESULTS
The frequency of all markers (at IL-1A +4845 and IL-1B -511 and VNTR) showed no association wih AgP in relatives (P>0.05). Tests of association by Family-Based Association Test showed no difference in the distribution of the allele 1 of IL-1B-511 under all three genetic models tested (Additive: Z=0.389, P=0.6969; Dominant: Z=0.089, P=0.9287; Recessive: Z=0.089, P=0.9287). The distribution of the allele 1 of IL- 1A+4845 also showed no significant difference under all three models (P>0.05). But when all AgP patients were stratified by the clinical subtype, the frequencies of A1A1 genotype and allele 1 at IL-1B-511 were significantly increased in the localized subtype AgP patients compared to unaffected (genotype: 43.8% vs 22.8%,OR=7.32,95% CI=1.84-29.11,P=0.005; allele 1: 71.9% vs 41.2%,OR=3.64,95% CI=1.55-8.58,P=0.002), while no significant difference was observed between the generalized subtype and the unaffected (genotype: P=0.88, allele: P=0.64).


CONCLUSIONS
The polymorphism of IL-1B-511 may have an effect on the susceptibility of localized AgP in Chinese population. It should be tested in larger family samples.
Ren
Xiu-Yun
XY
Department of Periodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
Xu
Li
L
Meng
Huan-Xin
HX
D000328:Adult; D010520:Aggressive Periodontitis / Q000235:genetics*; D000483:Alleles; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide; D012189:Retrospective Studies; D055815:Young Adult
D007375:Interleukin-1