My. Ruiz et Jl. Olivares, Three-loci HLA haplotypes in Spanish celiac children and healthy subjects:Estimation of linkage disequilibrium and haplotype frequencies, AM J GASTRO, 96(5), 2001, pp. 1455-1459
OBJECTIVES: The aim of this study was to compare the linkage disequilibrium
parameters and the frequencies of the three-loci HLA haplotypes in childre
n with celiac disease and in a control population within the same geographi
cal area.
METHODS: A total of 38 celiac children were studied. HLA typing was perform
ed by microlymphocytotoxicity assay using T and B cells separated by monocl
onal antibody labeled immunomagnetic particles (IMB). Three-loci haplotype
frequency (pABC) depend on each gene frequency (pA, pB, and pC), and a corr
ection factor (Delta) and takes the form: pABC = pA X pB X pC + Delta ABC.
The existence of a linkage disequilibrium was assessed by chi (2) test usin
g 2 X 2 X 2 contingency tables for gametic association.
RESULTS: There was a higher frequency of A1/B8/Cw7, A1/B8/DR3, A1/B8/DQ2, A
19/B12/DQ2, B8/Cw7/DR3, B8/Cw7/DQ2, B8/DR3/DQ2, and B12/DR7/DQ2 in celiac c
hildren than in the control population.
CONCLUSIONS: From the comparative study of celiac and healthy population wi
thin the same area, we conclude that these three-loci haplotypes could dete
rmine genetic susceptibility to celiac disease. (C) 2001 by Am. Cell. of Ga
stroenterology.