Genome-wide scan identifies CDH13 as a novel susceptibility locus contributing to blood pressure determination in two European populations.

Hypertension is a complex disease that affects a large proportion of adult population. Although approximately half of the inter-individual variance in blood pressure (BP) level is heritable, identification of genes responsible for its regulation has remained challenging. Genome-wide association study (GWAS) is a novel approach to search for genetic variants contributing to complex diseases. We conducted GWAS for three BP traits [systolic and diastolic blood pressure (SBP and DBP); hypertension (HYP)] in the Kooperative Gesundheitsforschung in der Region Augsburg (KORA) S3 cohort (n = 1644) recruited from general population in Southern Germany. GWAS with 395,912 single nucleotide polymorphisms (SNPs) identified an association between BP traits and a common variant rs11646213 (T/A) upstream of the CDH13 gene at 16q23.3. The initial associations with HYP and DBP were confirmed in two other European population-based cohorts: KORA S4 (Germans) and HYPEST (Estonians). The associations between rs11646213 and three BP traits were replicated in combined analyses (dominant model: DBP, P = 5.55 x 10(-5), effect -1.40 mmHg; SBP, P = 0.007, effect -1.56 mmHg; HYP, P = 5.30 x 10(-8), OR = 0.67). Carriers of the minor allele A had a decreased risk of hypertension. A non-significant trend for association was also detected with severe family based hypertension in the BRIGHT sample (British). The novel susceptibility locus, CDH13, encodes for an adhesion glycoprotein T-cadherin, a regulator of vascular wall remodeling and angiogenesis. Its function is compatible with the BP biology and may improve the understanding of the pathogenesis of hypertension.

Low Serum IGF-1 in Boys with Recent Onset of Juvenile Idiopathic Arthritis.

BACKGROUND: Liver-derived insulin-like growth factor-1 (IGF-1) contributes bone formation. Decreased IGF-1 levels are common in juvenile idiopathic arthritis (JIA), but whether IGF-1 is related to sex and differ during the pathogenic progress of JIA is unknown. OBJECTIVE: The aim of this study was to examine IGF-1 levels in boys and girls with newly diagnosed JIA, with established JIA and in controls. METHODS: The study group included 131 patients from the Estonian population-based prevalence JIA study. Blood samples were obtained from 27 boys and 38 girls with early JIA (≤1 month from the diagnosis), 29 boys and 36 girls with established JIA (mean disease duration 18 months), and from 47 age- and sex-matched controls. RESULTS: IGF-1 levels in boys were significantly decreased in early JIA compared to male controls, while IGF-1 levels in girls were comparable between JIA and controls. In early JIA, IGF-1 levels were 12-fold lower in boys relative to girls. In controls, IGF-1 levels correlated with both age and height, while these correlations were lost in boys with early JIA. CONCLUSION: We report a sex-dependent deficiency in serum IGF-1 in boys with early JIA, which argues for sex-related differences in biological mechanisms involved in the disease pathogenesis.

Differential expression profile of growth hormone/chorionic somatomammotropin genes in placenta of small- and large-for-gestational-age newborns.

CONTEXT: The human growth hormone/chorionic somatomammotropin (hGH/CSH) locus at 17q22-24, consisting of one pituitary-expressed postnatal (GH1) and four placenta-expressed genes (GH2, CSH1, CSH2, and CSHL1), is implicated in regulation of postnatal and intrauterine growth. A positive correlation has been reported between the offspring's birth weight and serum placental GH (coded by GH2) and placental lactogen (coded by CSH1, CSH2) levels in pregnant women. OBJECTIVE: The objective of the study was the investigation of the hypothesis that the mRNA expression profile of placental hGH/CSH genes contributes to the determination of birth weight. DESIGN AND SUBJECTS: We developed a sensitive, fluorescent-labeled semiquantitative RT-PCR assay coupled with gene-specific restriction analysis, capable of distinguishing alternative splice-products of individual placental hGH/CSH genes and quantification of their relative expression levels. The detailed profile of alternative transcripts of GH2, CSH1, CSH2, and CSHL1 genes in placenta from uncomplicated term pregnancies of the REPROMETA sample collection was addressed in association with the birth weight of newborns, grouped as appropriate for gestational age (AGA; n = 23), small for gestational age (SGA; n = 15), and large for gestational age (LGA; n = 34). RESULTS: The majority of pregnancies with SGA newborn showed down-regulation of the entire hGH/CSH cluster in placenta, whereas in the case of LGA, the expression of CSH1-1, CSH2-1, and CSHL1-4 mRNA transcripts in placenta was significantly increased compared with AGA newborns (P < 0.0001, P = 0.009, P = 0.002, respectively). CONCLUSION: The expression profile of placental hGH/CSH genes in placenta is altered in pregnancies accompanied by SGA and LGA compared with AGA newborns, and thus, it may directly affect the circulating fetal and maternal placental GH and placental lactogen levels.