EVIDENCE FOR LINKAGE OF CHROMOSOME 12Q15-Q24.1 MARKERS TO HIGH TOTAL SERUM IGE CONCENTRATIONS IN CHILDREN OF THE GERMAN MULTICENTER ALLERGYSTUDY

Linkage of asthma and high total serum IgE levels to chromosome 12q15- q24.1 has been recently described. To evaluate this region further in regard to total IgE responsiveness, we genotyped 52 unrelated German c hildren with persistently ''high'' total serum IgE (selected from a no ninterventional prospective multicenter cohort study) and their parent s. We carefully defined a most extreme IgE phenotype and analyzed it a s a dichotomous trait. We tested for linkage between high total IgE co ncentrations and nine polymorphic microsatellite markers on chromosome 12q15-q24.1 using the transmission/disequilibrium test. Evidence for linkage and allelic association for high total IgE was observed for fo ur markers in this region. This study demonstrates the value of using extreme phenotypes in genetic analysis of a complex quantitative trait . (C) 1997 Academic Press.