Loci on murine chromosomes 7 and 13 that modify the phenotype of the NOA mouse, an animal model of atopic dermatitis

The NOA (Naruto Research Institute Otsuka Atrichia) mouse is an animal mode l of allergic or atopic dermatitis, a condition characterized by ulcerative skin lesions with accumulation of mast cells and increased serum IgE. We r eported earlier that a major gene responsible for dermatitis in the NOA mou se lay in the middle of chromosome 14, and that the incidence of disease cl early differed according to parental strain: the mode of inheritance was au tosomal recessive with incomplete penetrance. In the study reported here, w e searched for genes that might modify the NOA phenotype, and we identified two candidate loci that appeared to contain genes capable of modifying ato pic or allergic dermatitis, one in the middle of chromosome 7 (chi (2) = 14 .66; P = 0.00013 for D7Mit62) and the other in the telomeric region of chro mosome 13 (chi (2) = 15.352; P = 0.000089 for D13Mit147). These loci corres pond to regions of synteny in human chromosomes where linkages to asthma, a topy, or related phenotypes, such as serum IgE levels, have been documented .