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 gene for Prader-Willi syndrome (PWS). One feature of this neurogenetic disorder is hyperphagia resulting in extreme obesity observed later in development. OBJECTIVE AND DESIGN: In this study we have used single-strand conformation polymorphism (SSCP) analysis to identify sequence variants at the human necdin gene. Furthermore we tested whether these variants were associated with 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 the polymorphisms were not significantly different between lower and higher body mass index (BMI) subjects. CONCLUSIONS: Hence, it is unlikely that these polymorphisms play a major role in the emergence of juvenile onset human obesity.