FINDING AN OBESITY GENE - A TALE OF MICE AND MAN

The term “complex disease” has been coined for conditions that arise from multifaceted interactions of environmental and heritable factors. It encompasses some of the most common disorders, such as hypertension, ischemic heart disease, and obesity. The heritability of these disorders deviates in important ways from that of classic, (mono)genetic diseases: no simple mendelian mode of transmission is apparent, and the severity of the disorders shows quantitative, unimodal variation rather than a dichotomous distribution. Complex traits are regarded as polygenic and multifactorial, with the phenotype representing the net effect of all contributing genes and environmental factors. These characteristics render the hunt. © 1995, Massachusetts Medical Society. All rights reserved.