title: In Search for the Genetic Basis of Quality of Life in Healthy Swedish Women--A GWAS Study Using the iCOGS Custom Genotyping Array.
abstract: BACKGROUND
  Quality of life (QoL) is increasingly measured in both research and clinical practice. QoL-assessments are built on a long, empirically-based, and stringent approach. There is ample evidence that QoL is, in part, heritable. We therefore performed a GWAS relating genetic variation to QoL in healthy females.
  
  
  METHODS
  In 5,142 healthy females, background characteristics (e.g. demographic, clinical, lifestyle and psychological factors) and QoL by means of the EORTC QLQ-C30 were measured. Moreover, women were genotyped using a custom array including ~210,000 single nucleotide polymorphisms (SNPs). Initially, SNPs were related to each QoL-domain, by means of partially adjusted (controlling for age and population stratification) and fully adjusted (controlling for age, population stratification, and background characteristics) regression analyses. Additionally, gene-based analyses were performed relating the combined effect of SNPs within each gene to QoL using the statistical software package VEGAS.
  
  
  RESULTS
  None of the associations between QoL and genetic variation (i.e. individual SNPs and genes) reached the bonferroni corrected significance level.
  
  
  CONCLUSIONS
  Reasons for a lack of association between genetic markers and QoL could be low variation in QoL-scores; selecting genetic markers not tagging QoL; or that the genetic effect that impacts one's QoL is mediated through biological pathways rather than the effect of single SNPs or genes. Therefore, we opt for a pathway-based or system biology approach as a complementary and powerful approach to analyze the combined effect of genes and their biological implications in future studies focusing on QoL-issues.
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Medical Psychology, Academic Medical Center, Amsterdam, The Netherlands; Department of Medical and Clinical Psychology, Tilburg University, Tilburg, The Netherlands.
authors.forename: Dounya
authors.initials: D
authors.lastname: Schoormans
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Hatef
authors.initials: H
authors.lastname: Darabi
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Human Genetics, Genome Institute of Singapore, Singapore, Singapore.
authors.forename: Jingmei
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Brandberg
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Eriksson
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Koos H
authors.initials: KH
authors.lastname: Zwinderman
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Department of Medical Psychology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Mirjam A G
authors.initials: MA
authors.lastname: Sprangers
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Hall
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D055106:Genome-Wide Association Study / Q000379:methods*; D005838:Genotype; D064368:Healthy Volunteers; D006801:Humans; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D020641:Polymorphism, Single Nucleotide; D011788:Quality of Life; D013548:Sweden; D044465:White People / Q000235:genetics*