Chronic and recurrent otitis media: A genome scan for susceptibility loci

Otitis media ( OM) is the most common childhood disease. Almost all children experience at least one episode, but morbidity is greatest in children who experience chronic/recurrent OM(COME/ROM). There is mounting evidence that COME/ROM clusters in families and exhibits substantial heritability. Subjects who had tympanostomy tube surgery for COME/ROM (probands) and their families were recruited for the present study, and an ear examination was performed, without knowledge of the subject's history, to determine presence of OM sequelae. In addition, tympanometric testing was performed at three frequencies (226, 630 or 710, and 1,400 Hz) to detect abnormal middle-ear mechanics, and hearing was screened at 20 dB for the speech frequencies. Of these families, 121 had at least two individuals who had received the diagnosis of COME/ROM ( 364 affected and genotyped individuals), of whom 238 affected and informative relative pairs were used for analyses. Single-point nonparametric linkage analysis provided evidence of linkage of COME/ROM to chromosome 10q at marker D10S212 (LOD 3.78; P = 3.0 x 10(-5)) and to chromosome 19q at marker D19S254 (LOD 2.61; P = 5.3 x 10(-4)). Analyses conditional on support for linkage at chromosomes 10q and 19q resulted in a significant increase in LOD score support on chromosome 3p ( between markers D3S4545 and D3S1259). These results suggest that risk of COME/ROM is determined by interactions between genes that reside in several candidate regions of the genome and are probably modulated by other environmental risk factors.