Backgrounds/Objectives:This panel study was to predict the incidences of pediatric obesity by the interaction of sodium (Na) intake and nine single-nucleotide polymorphisms (SNPs) of salt-sensitive genes (SSGs), ACE(angiotensin-converting enzyme), ADD1 G460W,AGT M235T,CYP11β2 (cytochrome P450 family 11-subfamily β-2, -aldosterone synthase),GNB3 C285T,GRK4(A142V)(G-protein-coupled receptor kinases type 4),GRK4 (A486V),NEDD4L (neural precursor cell expressed developmentally downregulated 4 like; rs2288774) and SLC12A3 (solute carrier family 12 (Na/Cl transporters)-member 3), selected from genome-wide association study.
Non-obese (non-OB) Korean children of 9 years old were recruited from eight elementary schools in Seoul in 2007 and 2009, each. Follow-up subjects (total=798) in 2010 and 2012 were final participants. Participants were classified as OB group for those whose body mass index were over the 85th percentile using the \'Korean National Growth Charts\', and others were classified as non-OB. With nine SNPs typing, the genetic interaction with the variation of Na intake for 3 years was evaluated as an obesity risk.
The obesity incidence rate for non-OB children at baseline after 3 years was 10.31%. Na intake in non-OB after 3 years was significantly decreased compared with the baseline, whereas Na intake reduction was undetectable in OB. We found gender differences on association between the changes of Na intake and the obesity incidence for 3 years by the SSG variation. Odds ratio for the obesity risk was 5.75 times higher in girls having hetero/mutant types of NEDD4L with higher Na intakes (Q2+Q3+Q4 in quartiles) compared with that in the wild type with the lowest Na intake (Q1). Girls with hetero/mutant of CYP11β2 tended to increase the obesity incidence as Na intake increased (Q1From this panel study and the previous cross-sectional study, we found CYP11β2 as the common gene, powerful to explain the interaction between obesity incidence and Na intake, in particular, among girls. Girls with hetero/mutant allele of this gene should reduce their daily Na intake to prevent obesity.

Genetic variation of NEDD4L has been associated with hypertension and related phenotypes with conflicting results, probably attributable to gender-, age- and ethnicity-related variations in its phenotypic expression. We evaluated the association of three representative polymorphisms in NEDD4L (rs2288774, rs3865418 and rs4149601) with essential hypertension (EH) in a community-based sample of men (n = 1029) and women (n = 869) belonging to Han Chinese, Southern China, to probe whether gender interacts with NEDD4L in contributing to the risk of EH. In this population sample, rs4149601 was excluded from further analysis due to deviation from Hardy-Weinberg equilibrium. For two other variants tested, the allele frequencies and genotype distributions did not differ between cases and controls (p > 0.05) when both genders were combined. However, sex-stratified analysis revealed that the distribution of the dominant model of rs2288774 (TC + CC versus TT) and the additive and dominant (CT + TT versus CC) models of rs3865418 differed significantly between cases and controls in men (p = 0.044, 0.041 and 0.016, respectively) but not in women. After adjusting for confounding factors, logistic regression analysis showed that rs2288774 and rs3865418 (in the dominant model) were still significantly associated with EH (rs2288774: OR = 0.73, 95% CI = 0.57-0.95, p = 0.017 and rs3865418: OR = 0.71, 95% CI = 0.55-0.92, p = 0.009) in men. There was a significant interaction between the NEDD4L genotype and gender (p for interaction: 0.046 for rs2288774 and 0.033 for rs3865418). Genetic variation in NEDD4L may have sex-dependent effects in the development of EH in Han Chinese. Previous studies that ignore gender-specific effects in their design and interpretation could have failed to identify a uniform conclusion.

We previously localized type 2 diabetes (T2D)-susceptibility genes to five chromosomal regions through a genome-wide linkage scan of T2D and age of diagnosis (AOD) in the African American subset of the GENNID sample. To follow up these findings, we repeated the linkage and association analysis using genotypes on an additional 9203 fine-mapping single nucleotide polymorphisms (SNPs) selected to tag genes under the linkage peaks. In each of the five regions, we confirmed linkage and inferred the presence of ≥2 susceptibility genes. The evidence of multiple susceptibility genes consisted of: (1) multiple linkage peaks in four of the five regions; and (2) association of T2D and AOD with SNPs within ≥2 genes in every region. The associated genes included 3 previously reported to associate with T2D or related traits (GRB10, NEDD4L, LIPG) and 24 novel candidate genes, including genes in lipid metabolism (ACOXL) and cell-cell and cell-matrix adhesion (MAGI2, CLDN4, CTNNA2).

BACKGROUND: Human height is a highly heritable trait considered as an important factor for health. There has been limited success in identifying the genetic factors underlying height variation. We aim to identify sequence variants associated with adult height by a genome-wide association study of copy number variants (CNVs) in Chinese.
METHODS: Genome-wide CNV association analyses were conducted in 1,625 unrelated Chinese adults and sex specific subgroup for height variation, respectively. Height was measured with a stadiometer. Affymetrix SNP6.0 genotyping platform was used to identify copy number polymorphisms (CNPs). We constructed a genomic map containing 1,009 CNPs in Chinese individuals and performed a genome-wide association study of CNPs with height.
RESULTS: We detected 10 significant association signals for height (p<0.05) in the whole population, 9 and 11 association signals for Chinese female and male population, respectively. A copy number polymorphism (CNP12587, chr18:54081842-54086942, p = 2.41 × 10(-4)) was found to be significantly associated with height variation in Chinese females even after strict Bonferroni correction (p = 0.048). Confirmatory real time PCR experiments lent further support for CNV validation. Compared to female subjects with two copies of the CNP, carriers of three copies had an average of 8.1% decrease in height. An important candidate gene, ubiquitin-protein ligase NEDD4-like (NEDD4L), was detected at this region, which plays important roles in bone metabolism by binding to bone formation regulators.
CONCLUSIONS: Our findings suggest the important genetic variants underlying height variation in Chinese.

BACKGROUND: Hypertension affects > 18.8% of adults in China. Indeed, hypertension is the most prevalent risk factor for cardiovascular morbidity and mortality worldwide. Genetic variation is thought to contribute to the etiology of hypertension. NEDD4L is a candidate gene for hypertension, both functionally and genetically. The purpose of the current study was to investigate the relationship between the variation in NEDD4L and essential hypertension in Kazakh, which is a relatively isolated population with a pure genetic background and is an ideal population to study genetic mechanisms of hypertension.
METHODS: We screened the promoter and exons of NEDD4L in 94 Kazakh hypertensive individuals to identify representative variations. Then, by genotyping the representative variations in the Kazakh general population, a case-control study was conducted.
RESULTS: By systemically screening variations of NEDD4L, we did not identify any functional mutations in NEDD4L. A new common variation (296921-296923delTTG), which is not found in the NCBI database, was identified. Three representative variations (296921-296923delTTG, rs2288774, and rs2288775) were successfully genotyped in the Kazakh general population. The distribution of the dominant model (AA vs. AG+GG) of rs2288775, the additive model, and the recessive model (II+ID vs. DD) of 296921-296923delTTG differed significantly between the cases and controls in females (P = 0.040, P = 0.024, and P = 0.007, respectively). After adjusting for confounding factors, logistic regression analysis showed that rs2288775 (in the dominant model) and 296921-296923delTTG (in the recessive model) were significantly associated with hypertension (rs2288775: OR = 1.479, 95% CI = 1.011-2.064, p = 0.044; and 296921-296923delTTG: OR = 1.908, 95% CI = 1.020-3.568, p = 0.043) in females. The frequency of the D-C-G haplotype was significantly higher for cases than for controls in females (P = 0.020). There was a significant interaction between the NEDD4L genotype and gender (P for interaction: 0.045 for rs2288775 and 0.064 for 296921-296923delTTG), but there was no significant interaction between the NEDD4L genotype and smoking (P for interaction: 0.616 for rs2288775 and 0.447 for 296921-296923delTTG). For females and total participants, the urinary Na excretion rate was significantly lower in the DD than the I/I+I/D individuals (P = 0.032 and P = 0.027 respectively).
CONCLUSIONS: The genetic variations of NEDD4L may be associated with essential hypertension in females in the Kazakh general population.

Neural precursor cell expressed developmentally down-regulated 4-like (NEDD4L) gene may play an important role in the development of hypertension by regulating the amiloride-sensitive epithelial sodium channel for sodium reabsorption. Recently, a functional polymorphism located at the last nucleotide of exon 1 (rs4149601) of the NEDD4L gene were found to be associated with hypertension both in African Americans and whites, and a \"flip-flop\" association with hypertension was found in two white samples for a polymorphism located at intron 13 (rs3865418). In this study, we aimed at examining the role of these two variants on essential hypertension in Chinese Hans. In a population-based association study, we observed significantly higher prevalence of T allelic frequencies (p = 0.023) in hypertensives than normotensives. In logistic regression analysis, the stronger association was found under the additive model with an odds ratio of 1.31 (1.04-1.67) for T allele (p = 0.025). The association remained significant (p = 0.039) with an odds ratio of 1.29 (1.01-3.66) when adjusting for age and sex. We also constructed an ANCOVA factorial model by using clinical parameters as the dependent variable for rs3865418 polymorphisms. A significantly higher diastolic blood pressure was observed at rs3865418 in the dominant model for the T allele (p = 0.009). The positive association still exist after controlling age and sex (p = 0.013). For rs4149601 polymorphism, however, we did not observe a positive association with hypertension by implicating either logistic regression models or ANCOVA models. Thus, our results support rs3865418 but not rs4149601 polymorphism of NEDD4L gene implicated in the prevalence of hypertension in Chinese Hans.

BACKGROUND: Postural change in systolic blood pressure (SBP) is prospectively associated with several disease outcomes including hypertension, stroke, and coronary heart disease. The objective of this study was to characterize further a possible quantitative trait locus on chromosome 18q21 influencing SBP response to a postural challenge.
METHODS: A prior genome scan of postural SBP response in 636 subjects of white ethnicity from 285 hypertensive sibships in the Hypertension Genetic Epidemiology Network (HyperGEN) indicated suggestive evidence for linkage on chromosome 18q21. This study included a de novo set of 452 African American pedigrees from the HyperGEN study and an expanded set of 372 white pedigrees. Variance components linkage analysis of postural SBP change was conducted using microsatellite markers on chromosome 18, and association studies were performed with a common single nucleotide polymorphism (variant 13) in the gene encoding NEDD4L, a key regulator of fine sodium reabsorption in the distal nephron.
RESULTS: Combined analysis of all white and African American pedigrees yielded a LOD score of 4.25 at 80 cM on chromosome 18q21, with at least nominal evidence of linkage at this position in both white (LOD: 3.43) and African American (LOD: 1.14) subjects. Postural SBP response was associated with variant 13 of the NEDD4L in a subset of white subjects taking medications effective in treating sodium volume-dependent hypertension (alpha1-blockers, calcium channel blockers, and/or diuretics).
CONCLUSIONS: These data provide further evidence for a quantitative trait locus on chromosome 18q21 influencing postural change in SBP.