Association of essential hypertension with a microsatellite marker on chromosome 17

Organization and evolution of mitochondrial gene clusters in human

Currently, the spatial patterns of mitochondrial genes and how the genomic localization of (pseudo)genes originated from mitochondrial DNA remain largely unexplained. The aim of this study was to elucidate the organization of mitochondrial (pseudo)genes given their evolutionary origin. We used a keyword finding method and a bootstrapping method to estimate parameter values that represent the distribution pattern of mitochondrial genes in the nuclear genome. Almost half of mitochondrial genes showing physical clusters were located in the pericentromeric and subtelomeric regions of the chromosome. Most interestingly, the size of these clusters ranged from 0.085 to 3.2 Mb (average+/-SD 1.3+/-0.73 Mb), which coincides with the size of the evolutionary pocket, or the average size of evolutionary breakpoint regions. Our findings imply that the localization of mitochondrial genes in the human genome is determined independent of adaptation.

Single-nucleotide polymorphisms near the microsatellite D17S1303 and the development of hypertension in a 6-year longitudinal study

This study examined the association of tagging single-nucleotide polymorphisms (SNPs) in the 130 kb region surrounding the microsatellite D17S1303 on chromosome 17p12 with the development of hypertension after 6 years in a cohort of 232 Hong Kong Chinese adults. Four SNPs (rs9899362, rs10491093, rs11658572 and rs9913883) were associated with the development of hypertension (P<0.05), but these associations require confirmation in future studies. Nevertheless, our study provides further evidence for the presence of an unidentified gene or a regulatory element predisposing to hypertension in a region approximately 24 kb downstream of D17S1303.

Genome-wide scan of plasma cholecystokinin in baboons shows linkage to human chromosome 17

OBJECTIVE

Cholecystokinin (CCK) is known to inhibit food intake and is an important signal for controlling meal volume, indicating a possible role in weight regulation. Our objective was to investigate genetic influences on plasma CCK in baboons.

RESEARCH METHODS AND PROCEDURES

Subjects were 376 baboons (males = 113, females = 263) from the Southwest National Primate Research Center, housed at the Southwest Foundation for Biomedical Research, San Antonio, Texas. Anthropometric and biochemical parameters were analyzed. Genetic effects on plasma CCK were estimated by the maximum likelihood-based variance components method implemented in the software program SOLAR (Sequential Oligogenic Linkage Analysis Routines).

RESULTS

Male baboons (32.7 +/- 6 kg) were much heavier than females (20.2 +/- 4 kg). Similarly, mean (+/- standard deviation) plasma CCK values were also higher in male baboons (13.8 +/- 6 pM) than female baboons (12.5 +/- 4 pM). Significant heritabilities were observed for plasma CCK (0.14 +/- 0.1, p < 0.05), body weight (h2 = 0.62 +/- 0.15, p < 10(-8)), and glucose (h2 = 0.68 +/- 0.17, p < 10(-7)). A genome-wide scan of plasma CCK detected a strong signal for a quantitative trait locus (QTL) on chromosome 17p12-13 [logarithm of the odds (LOD) = 3.1] near marker D17S804. Suggestive evidence of a second QTL was observed on chromosome 4q34-35 (LOD = 2.3) near marker D4S2374.

DISCUSSION

A substantial contribution of additive genetic effects to the variation in plasma levels of CCK was demonstrated in baboons. The identification of a QTL for plasma CCK on chromosome 17p is significant, as several obesity-related traits such as BMI, leptin, adiponectin, and acylation stimulating protein have already been mapped to this region.

The molecular basis of pediatric hypertension

Blood pressure, the product of cardiac output and peripheral vascular resistance, follows a circadian rhythm and is altered by a host of circulating and local substances and by many physiologic events. The number of genes, signaling pathways, and systems involved in blood pressure regulation is enormous, and dissecting those factors that are most important in hypertension has proven challenging. This article discusses molecular mechanisms of hypertension in several conditions in which mutations in a single gene give rise to hypertension and then considers the contribution of these and other genes to essential hypertension.

Association of hypertension with single nucleotide polymorphisms in the quantitative trait locus for abdominal obesity-metabolic syndrome on chromosome 17

Genome scan in Chinese revealed an association of blood pressure with the microsatellite marker D17S1303, which lies in a quantitative trait locus for the abdominal obesity-metabolic syndrome (AOMS2) at 17p12 on chromosome 17. We previously reported that D17S1303 was associated with hypertension and obesity. Therefore, we studied 10 single nucleotide polymorphisms (SNP) within 3 kb of D17S1303. One hundred and eighty hypertensive subjects (91 men, 89 women, age 53+/-12 years) and 180 normotensive matched controls (91 men, 89 women, age 52+/-11) were genotyped using the Sequenom genotyping platform. Allelic frequencies in these Chinese subjects differed from those reported for Caucasians. Three SNPs (rs11656507, rs1357926, rs852319) were homozygous in our subjects. The genotype frequencies of rs852320, rs852321 and rs852322 did not differ between hypertensive and normotensive subjects. However, there were significant differences for rs1525402 (P=0.048), rs2692343 (P=0.022), rs2692344 (P=0.017) and rs2321313 (P=0.028). A four-locus haplotype comprising G at rs1525402, C at rs2692343, C at rs2692344 and G at rs2321313 was associated with lower systolic blood pressure (P=0.023) and normotension (P=0.048). Our results provide further evidence that there is a gene, as yet unidentified, influencing blood pressure in the vicinity of D17S1303 in a quantitative trait locus for abdominal obesity-metabolic syndrome at 17p12.