New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Genes Involved in Initial Follicle Recruitment May Be Associated with Age at Menopause

Context: Timing of menopause is largely influenced by genetic factors. Because menopause occurs when the follicle pool in the ovaries has become exhausted, genes involved in primordial follicle recruitment can be considered as candidate genes for timing of menopause. Objective: The aim was to study the association of 23 tagging single nucleotide polymorphisms in five genes [Anti-Mullerian hormone (AMH), AMH type II receptor (AMHR2), bone morphogenetic protein 15 (BMP15), forkhead transcription factor L2 (FOXL2), and growth differentiation factor-9 (GDF9)] involved in recruitment of the primary follicle pool, including the AMHR2 gene, which has recently been associated with age at menopause. Design: We conducted a cross-sectional association study. Setting and Participants: We studied a population-based sample of 3616 Dutch women with natural menopause. Main Outcome Measure: We measured age at natural menopause. Results: Both studied AMHR2 tagging single nucleotide polymorphisms (rs2002555 and rs11170547) in the AMHR2 gene were associated with age at natural menopause in interaction with parity. Parous rs2002555 G/G carriers had menopause 1 yr later compared with A/A carriers (P = 0.01). For rs11170547, each minor allele (T) was associated with a 0.41-yr later onset of menopause in parous women (P = 0.01). Additionally, rs6521896 in BMP15 was associated with later menopause (beta = 0.41; P = 0.007). Variants in the AMH, FOXL2, and GDF9 genes were not associated with timing of menopause. Conclusions: The present study confirms an earlier finding that variation in the AMHR2 gene modifies the relation between parity and age at natural menopause. In combination with the association of BMP15 with menopausal age, we find that there is evidence that genes involved in primary follicle recruitment influence timing of menopause. (J Clin Endocrinol Metab 96: E473-E479, 2011

Interactions between Genetic Variants in AMH and AMHR2 May Modify Age at Natural Menopause

The onset of menopause has important implications on women’s fertility and health. We previously identified genetic variants in genes involved in initial follicle recruitment as potential modifiers of age at natural menopause. The objective of this study was to extend our previous study, by searching for pairwise interactions between tagging single nucleotide polymorphisms (tSNPs) in the 5 genes previously selected (AMH, AMHR2, BMP15, FOXL2, GDF9). We performed a cross-sectional study among 3445 women with a natural menopause participating in the Prospect-EPIC study, a population-based prospective cohort study, initiated between 1993 and 1997. Based on the model-based multifactor dimensionality reduction (MB-MDR) test with a permutation-based maxT correction for multiple testing, we found a statistically significant interaction between rs10407022 in AMH and rs11170547 in AMHR2 (p = 0.019) associated with age at natural menopause. Rs10407022 did not have a statistically significant main effect. However, rs10407022 is an eQTL SNP that has been shown to influence mRNA expression levels in lymphoblastoid cell lines. This study provides additional insights into the genetic background of age at natural menopause and suggests a role of the AMH signaling pathway in the onset of natural menopause. However, these results remain suggestive and replication by independent studies is necessary

Overview of the Top 10 Pairwise Interactions between tSNPs in Genes Involved in Initial Follicle Recruitment.

<p>Abbreviations: tSNP, tagging Single Nucleotide Polymorphism.</p>*<p>P-values are reported after adjustment for multiple testing, based on a permutation-based maxT correction with 999 replicates.</p

Meta-analyses identify 13 loci associated with age at menopause and highlight DNA repair and immune pathways

To newly identify loci for age at natural menopause, we carried out a meta-analysis of 22 genome-wide association studies (GWAS) in 38,968 women of European descent, with replication in up to 14,435 women. In addition to four known loci, we identified 13 loci newly associated with age at natural menopause (at P < 5 x 10(-8)). Candidate genes located at these newly associated loci include genes implicated in DNA repair (EXO1, HELQ, UIMC1, FAM175A, FANCI, TLK1, POLG and PRIM1) and immune function (IL11, NLRP11 and PRRC2A (also known as BAT2)). Gene-set enrichment pathway analyses using the full GWAS data set identified exoDNase, NF-kappaB signaling and mitochondrial dysfunction as biological processes related to timing of menopause