Systematic screening for mutations in the human necdin gene (NDN): identification of two naturally occurring polymorphisms and association analysis in body weight regulation

BACKGROUND: NDN, which codes for the human necdin protein, is a candidate g ene for Prader-Willi syndrome (PWS). One feature of this neurogenetic disor der is hyperphagia resulting in extreme obesity observed later in developme nt. OBJECTIVE AND DESIGN: In this study we have used single-strand conformation polymorphism (SSCP) analysis to identify sequence variants at the human ne cdin gene. Furthermore we tested whether these variants were associated wit h obesity in extremely obese German children and adolescents. RESULTS: Two gene variants could be identified: a g.1352T -->C polymorphism in the putative promotor region and a silent g.2311C -->T polymorphism in the coding region. Genotype and allele frequency distribution of both of th e polymorphisms were not significantly different between lower and higher b ody mass index (BMI) subjects. CONCLUSIONS: Hence, it is unlikely that these polymorphisms play a major ro le in the emergence of juvenile onset human obesity.