title: Gene set of nuclear-encoded mitochondrial regulators is enriched for common inherited variation in obesity.
abstract: There are hints of an altered mitochondrial function in obesity. Nuclear-encoded genes are relevant for mitochondrial function (3 gene sets of known relevant pathways: (1) 16 nuclear regulators of mitochondrial genes, (2) 91 genes for oxidative phosphorylation and (3) 966 nuclear-encoded mitochondrial genes). Gene set enrichment analysis (GSEA) showed no association with type 2 diabetes mellitus in these gene sets. Here we performed a GSEA for the same gene sets for obesity. Genome wide association study (GWAS) data from a case-control approach on 453 extremely obese children and adolescents and 435 lean adult controls were used for GSEA. For independent confirmation, we analyzed 705 obesity GWAS trios (extremely obese child and both biological parents) and a population-based GWAS sample (KORA F4, n = 1,743). A meta-analysis was performed on all three samples. In each sample, the distribution of significance levels between the respective gene set and those of all genes was compared using the leading-edge-fraction-comparison test (cut-offs between the 50(th) and 95(th) percentile of the set of all gene-wise corrected p-values) as implemented in the MAGENTA software. In the case-control sample, significant enrichment of associations with obesity was observed above the 50(th) percentile for the set of the 16 nuclear regulators of mitochondrial genes (p(GSEA,50) = 0.0103). This finding was not confirmed in the trios (p(GSEA,50) = 0.5991), but in KORA (p(GSEA,50) = 0.0398). The meta-analysis again indicated a trend for enrichment (p(MAGENTA,50) = 0.1052, p(MAGENTA,75) = 0.0251). The GSEA revealed that weak association signals for obesity might be enriched in the gene set of 16 nuclear regulators of mitochondrial genes.
authors: Department of Child and Adolescent Psychiatry, University of Duisburg-Essen, Essen, Germany.
authors: Nadja
authors: N
authors: Knoll
authors: Ivonne
authors: I
authors: Jarick
authors: Anna-Lena
authors: AL
authors: Volckmar
authors: Martin
authors: M
authors: Klingenspor
authors: Thomas
authors: T
authors: Illig
authors: Harald
authors: H
authors: Grallert
authors: Christian
authors: C
authors: Gieger
authors: Heinz-Erich
authors: HE
authors: Wichmann
authors: Annette
authors: A
authors: Peters
authors: Johannes
authors: J
authors: Hebebrand
authors: André
authors: A
authors: Scherag
authors: Anke
authors: A
authors: Hinney
mesh_terms: D000818:Animals; D016022:Case-Control Studies; D004195:Disease Models, Animal; D008040:Genetic Linkage; D055106:Genome-Wide Association Study; D006801:Humans; D015810:Linkage Disequilibrium; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D009765:Obesity / Q000235:genetics* / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D020641:Polymorphism, Single Nucleotide