Genetic polymorphisms of the IL-1alpha and IL-1beta genes in African-American LJP patients and an African-American control population.
BACKGROUND
A functional polymorphism of the interleukin-1 beta (IL-1beta) gene has been proposed to be a risk factor for periodontitis. In adult forms of periodontitis, non-smokers of northern European heritage carrying the "2" allele of the IL-1alpha-889 and the IL-1beta +3953 RFLPs in either the heterozygous or the homozygous state at both loci were observed to have a greater risk for developing severe periodontitis. Studies of early-onset periodontitis (EOP) found that allele "1" of both IL-1alpha-889 and IL-1beta +3953 was transmitted more frequently with the EOP phenotype. The purpose of the present study was to determine the prevalence of the IL-1alpha and IL-1beta genotype polymorphisms in an African-American (AA) control population and in 37 African-Americans with localized juvenile periodontitis (LJP).


METHODS
The IL-1alpha +4845 and IL-1beta +3953 loci were genotyped by PCR amplification, followed by restriction enzyme digestion and gel electrophoresis. The IL-1alpha +4845 locus, in linkage disequilibrium (>99%) with IL-1alpha-889, was genotyped because it is technically easier. Data were analyzed using r x c contingency tables.


RESULTS
The IL-1beta +3953 allele "1" was carried by >99% of the AA control population and by 100% of the AA LJP group, with most individuals being homozygous 1,1. The prevalence of the composite genotype with at least one allele "2" at each of the IL-1beta +3953 and IL-1alpha +4845 loci was 14% (AA control group) and 8% (AA LJP group).


CONCLUSIONS
Given the high frequency of the IL-1beta allele "1" in the African-American population, it would appear that knowledge of this +3953 polymorphism would provide little diagnostic or predictive information for LJP.
Walker
S J
SJ
Department of Pediatrics, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
Van Dyke
T E
TE
Rich
S
S
Kornman
K S
KS
di Giovine
F S
FS
Hart
T C
TC
D000328:Adult; D010520:Aggressive Periodontitis / Q000235:genetics*; D044383:Black People / Q000235:genetics*; D016022:Case-Control Studies; D005787:Gene Frequency; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics*; D017720:Molecular Epidemiology; D011110:Polymorphism, Genetic; D001741:Black or African American
D007375:Interleukin-1