Genetic studies of neuropeptide Y and neuropeptide Y receptors Y1 and Y5 regions in morbid obesity

Summary Synthesis and release of neuropeptide Y (NPY) are both regulated by leptin binding to its hypothalamic receptor mediating some of the effects of leptin on food intake. Moreover, NPY administration is a powerful stimulant of feeding behaviour. Thus, we investigated the potential implication of NPY, NPY-Y1 and -Y5 subtype receptors [rNPY-Y1/-Y5] in the development of human obesity. Two complementary genetic approaches were used: 1) linkage analyses between obesity and polymorphic markers located nearby NPY and rNPY-Y1/-Y5 genes (respectively on chromosomes 7p15.1 and 4q[31.3–32]) in 93 French Caucasian morbidly obese families; 2) single strand conformation polymorphism (SSCP) scanning of the coding region of the NPY and rNPY-Y1 genes performed in 50 unrelated obese patients ascertained on the basis of a body mass index of 27 kg/m² or more and a family history of obesity. No evidence of linkage between morbid obesity or obesity-related quantitative traits and NPY and rNPY-Y1/Y5 regions was found in this population. Moreover, SSCP scanning revealed no mutation in the coding region of NPY and rNPY-Y1 genes among obese subjects. These results suggest that NPY and NPY-Y1/Y5 receptors are unlikely to be implicated in the development of human morbid obesity, at least in the French Caucasian population. [Diabetologia (1997) 40: 671–675] Received: 27 December 1996 and in revised form: 26 February 1997