Submitted to: Pediatric Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/19/2007
Publication Date: 10/1/2007
Citation: Voruganti, V.S., Goring, H.H., Diego, V.P., Cai, G., Mehta, N.R., Haack, K., Cole, S.A., Butte, N.F., Comuzzie, A.G. 2007. Genome-wide scan for serum ghrelin detects linkage on chromosome 1p36 in Hispanic children: Results from the Viva la Familia study. Pediatric Research. 62(4):445-450. Interpretive Summary: This study was conducted to identify chromosomal regions associated with childhood obesity and its related illnesses in the Hispanic population. A genome scan was performed on 1030 children enrolled in the Viva La Familia Study. A strong linkage signal on chromosome 1p36.2 was identified for fasting serum levels of ghrelin, insulin, insulin-like growth factor binding protein 1, homeostatic model assessment method (HOMA) and C-peptide. This indicates a strong genetic contribution to the variation in hormones that influence the regulation of food intake, metabolism, and growth. This region of chromosome 1p36 harbors many obesity-related candidate genes and thus seems to be an important region in relation to childhood obesity and risk for diabetes.
Technical Abstract: This study was conducted to investigate genetic influence on serum ghrelin and its relationship with adiposity-related phenotypes in Hispanic children (n = 1030) from the Viva La Familia study (VFS). Anthropometric measurements and levels of serum ghrelin were estimated and genetic analyses conducted according to standard procedures. Mean age, body mass index (BMI), and serum ghrelin were 11 +/- 0.13 y, 25 +/- 0.24 kg/m2 and 38 +/- 0.5 ng/mL, respectively. Significant heritabilities (p < 0.001) were obtained for BMI, weight, fat mass, percent fat, waist circumference, waist-to-height ratio, and ghrelin. Bivariate analyses of ghrelin with adiposity traits showed significant negative genetic correlations (p < 0.0001) with weight, BMI, fat mass, percent fat, waist circumference, and waist-to-height ratio. A genome-wide scan for ghrelin detected significant linkage on chromosome 1p36.2 between STR markers D1S2697 and D1S199 (LOD = 3.2). The same region on chromosome 1 was the site of linkage for insulin (LOD = 3.3), insulinlike growth factor binding protein 1 (IGFBP1) (LOD = 3.4), homeostatic model assessment method (HOMA) (LOD = 2.9, and C-peptide (LOD = 2.0). Several family-based studies have reported linkages for obesity-related phenotypes in the region of 1p36. These results indicate the importance of this region in relation to adiposity in children from the VFS.