Obesity is a common multifactorial disease with which environmental and genetic factors interact. Obesity is a risk factor for early mortality, metabolic and cardiovascular complications.The strongest evidence for a genetic component of human obesity is the familial clustering and the high concordance of body composition in monozygotic twins. However, the role of genetic factors in obesity is complex. The human genes which cause monogenic obesity are encoding leptin, leptin receptor, POMC and MC4R . Another common form of human obesity is poligenic. Candidate genes studies and genome-wide scans were applied in searching for genes underlying poligenic obesity in humans. As a result, the mutations which were found account for only a few parts of obese cases. More genom wide scans with a high number of polymorphic marker are needed to identify another chromosomal region in obesity. Such studies will provide significant progresses for treatment and preventive medicine of human obesity.

Keywords: Obesity, Multifactorial İnheritance, Leptin Gene, MC4R Gene, POMC Gene