Linkage study of early-onset obesity to leptin receptor gene in Italian children

Analyses of twins as well as adopted children have shown that obesity has a considerable genetic component. An identical by descent (IBD) study in obe se patients with very early onset of the disease has been performed in orde r to evaluate the linkage of the leptin receptor gene (OB-R) to obesity. Fo rty-eight couples of discordant (affected-unaffected) Italian sibs have bee n chosen. Two highly polymorphic microsatellites within introns 1 and 14 of OB-R have been scored. Analysis of the haplotypes did not show any evidenc e of linkage (p 0.076). Quantitative trait linkage analysis evaluated by re gressing the difference of the BMI between the two sibs of a pair as a func tion of the estimated proportion of alleles shared failed to show any signi ficative evidence for linkage. (C) 2000 Elsevier Science Inc.