Genome-wide Burden of Rare Short Deletions Is Enriched in Major Depressive Disorder in Four Cohorts
BIOLOGICAL PSYCHIATRY
Authors: Zhang, Xianglong; Abdellaoui, Abdel; Rucker, James; de Jong, Simone; Potash, James B.; Weissman, Myrna M.; Shi, Jianxin; Knowles, James A.; Pato, Carlos; Pato, Michele; Sobell, Janet; Smit, Johannes H.; Hottenga, Jouke-Jan; de Geus, Eco J. C.; Lewis, Cathryn M.; Buttenschon, Henriette N.; Craddock, Nick; Jones, Ian; Jones, Lisa; McGuffin, Peter; Mors, Ole; Owen, Michael J.; Preisig, Martin; Rietschel, Marcella; Rice, John P.; Rivera, Margarita; Uher, Rudolf; Gejman, Pablo V.; Sanders, Alan R.; Boomsma, Dorret; Penninx, Brenda W. J. H.; Breen, Gerome; Levinson, Douglas F.
Abstract
BACKGROUND: Major depressive disorder (MDD) is moderately heritable, with a high prevalence and a presumed high heterogeneity. Copy number variants (CNVs) could contribute to the heritable component of risk, but the two previous genome-wide association studies of rare CNVs did not report significant findings. METHODS: In this meta-analysis of four cohorts (5780 patients and 6626 control subjects), we analyzed the association of MDD to 1) genome-wide burden of rare deletions and duplications, partitioned by length (<100 kb or >100 kb) and other characteristics, and 2) individual rare exonic CNVs and CNV regions. RESULTS: Patients with MDD carried significantly more short deletions than control subjects (p = .0059) but not long deletions or short or long duplications. The confidence interval for long deletions overlapped with that for short deletions, but long deletions were 70% less frequent genome-wide, reducing the power to detect increased burden. The increased burden of short deletions was primarily in intergenic regions. Short deletions in cases were also modestly enriched for high-confidence enhancer regions. No individual CNV achieved thresholds for suggestive or significant association after genome-wide correction. p values < .01 were observed for 15q11.2 duplications (TUBGCP5, CYFIP1, NIPA1, and NIPA2), deletions in or near PRKN or MSR1, and exonic duplications of ATG5. CONCLUSIONS: The increased burden of short deletions in patients with MDD suggests that rare CNVs increase the risk of MDD by disrupting regulatory regions. Results for longer deletions were less clear, but no large effects were observed for long multigenic CNVs (as seen in schizophrenia and autism). Further studies with larger sample sizes are warranted.
Genetic variation in APOJ, LPL, and TNFRSF10B affects plasma fatty acid distribution in Alaskan Eskimos
AMERICAN JOURNAL OF CLINICAL NUTRITION
Authors: Voruganti, V. Saroja; Cole, Shelley A.; Ebbesson, Sven O. E.; Goering, Harald H. H.; Haack, Karin; Laston, Sandra; Wenger, Charlotte R.; Tejero, M. Elizabeth; Devereux, Richard B.; Fabsitz, Richard R.; MacCluer, Jean W.; Umans, Jason G.; Howard, Barbara V.; Comuzzie, Anthony G.
Abstract
Background: Alterations in plasma fatty acid distribution are linked to metabolic abnormalities related to type 2 diabetes and cardiovascular disease. Objective: The aim of this study was to investigate genetic factors influencing plasma fatty acid distribution in Alaskan Eskimos from the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study. Design: Fatty acids in plasma were measured by gas chromatography in 761 related individuals (>35 y of age). Results: Quantitative genetic analyses showed that fatty acid distribution is significantly heritable (P < 0.001), with heritabilities ranging from 0.33 to 0.55. A genome-wide scan for plasma fatty acids identified a 20-cM region on chromosome 8 (p12-p21) with a quantitative trait locus for monounsaturated fatty acids (logarithm of odds score = 3.8). The same region had a quantitative trait locus for polyunsaturated fatty acids (logarithm of odds score = 2.6). We genotyped single nucleotide polymorphisms (SNPs) in candidate genes in 8p12-p21 and found a significant association between fatty acids and SNPs in apolipoprotein J (APOJ), lipoprotein lipase (LPL), macrophage scavenger receptor 1 (MSR1), and tumor necrosis factor receptor superfamily member 10b (TNFRSF10B). A Bayesian quantitative trait nucleotide analysis based on a measured genotype model showed that SNPs in LPL, TNFRSF10B, and APOJ had strong statistical evidence of a functional effect (posterior probability >= 75%) on plasma fatty acid distribution. Conclusions: The results indicate that there is strong genetic influence on plasma fatty acid distribution and that genetic variation in APOJ, LPL, and TNFRSF10B may play a role. The GOCADAN study was registered at www.clinicaltrials.gov as NCT00006192. Am J Clin Nutr 2010;91:1574-83.