Note: a this variable is Blond tresses + blue-eyes regarding the 1908 data and you can Blond hair + blue/grey eyes on 2004 analysis.

Strategies

, Reference van Beijsterveldt, Groen-Blokhuis, Hottenga, Franic, Hudziak and you can Mutton 2013; Willemsen mais aussi al., Reference Willemsen, Vink, Abdellaoui, den Braber, van Beek and you will Draisma 2013) was included in this study according to the visibility away from mind-claimed analysis on the absolute locks and you will attention color together with visibility of genotype research towards the an Illumina 370, 660, 1M otherwise Affymetrix Perlegen-5.0, or 6.0 system. There have been eight,063 genotyped Dutch-origins participants, clustered inside step 3,407 parents having research into attention colour, and you may six,965 genotyped someone got data toward each other tresses and you may attention colour. Towards the genetic association study off attention colour (get a hold of Secondary question) all of the data was examined. To own bivariate genetic analyses when you look at the GCTA, all not related people were chosen, based on a hereditary relatedness matrix (GRM) cut-off 0.025 (Yang ainsi que al., Source Yang, Lee, Goddard and you can Visscher 2011). This kept step three,619 anyone to the bivariate analyses, having a hereditary relatedness comparable to lower than 3rd otherwise 4th cousin.

, Site Willemsen, Vink, Abdellaoui, den Braber, van Beek and Draisma 2013). Mature participants http://members.tripod.com/blk_nubianqueens/images/Miss_Thickums.jpg » alt= »Geek Dating Seiten kostenlos »> said their unique sheer locks colour from out of five choices: ‘fair/blond’, ‘hazel’, ‘red/auburn’, ‘black brown’, and you may ‘black’ and you may attention color with among about three alternatives: ‘blue/gray’, ‘green/hazel’ and ‘brown’. An equivalent questions on the eyes color and you may locks colour were replied by the teenage (14- in order to 18-year-old) twins when they accomplished the brand new Dutch Health insurance and Decisions Survey into the 2005 or 2006 (van Beijsterveldt et al., Reference van Beijsterveldt, Groen-Blokhuis, Hottenga, Franic, Hudziak and Mutton 2013). On the statistical analyses, we combined the new black colored, white brownish, and you can brownish locks color so you can ‘dark’, while the only hardly any people advertised a black colored hair color (Lin ainsi que al., Source Lin, Mbarek, Willemsen, Dolan, Fedko and Abdellaoui 2015). Created advised consent are extracted from the participants.

Age, sex, pure locks, and you may vision colour were extracted from Mature NTR survey 7, that was built-up in the 2004 (Willemsen ainsi que al

DNA extraction, purification, and genotype calling of the samples were performed at various points in time following the manufacturer’s protocols and genotype calling programs (Lin et al., Reference Lin, Mbarek, Willemsen, Dolan, Fedko and Abdellaoui 2015). For each platform, the individual SNPs were remapped on the build 37 (HG19), ALL 1000 Genomes Phase 1 imputation reference dataset (Auton et al., Reference Auton, Brooks, Durbin, Garrison, Kang and Korbel 2015). SNPs that failed unique mapping and SNPs with an allele frequency difference over 0.20 with the reference data were removed. SNPs with a minor allele frequency (MAF) < 0.01 were also removed, as well as SNPs that were out of Hardy–Weinberg Equilibrium (HWE) with p < 10 ?5 . The platform data were then merged into a single genotype set and the above SNP QC filters were reapplied. Samples were excluded from the data when their DNA was discordant with their expected sex or IBD status, the genotype missing rate was above 10%, the Plink F-inbreeding value was either larger than 0.10 or smaller than ?0.10, or they were an ethnic outlier based on EIGENSTRAT PCs calculated from the 1000G imputed data (Auton et al., Reference Auton, Brooks, Durbin, Garrison, Kang and Korbel 2015). Phasing of the samples and imputing cross-missing platform SNPs was done with MACH 1 (Li Abecasis, Reference Li and Abecasis 2006). The phased data were then imputed with MINIMAC to the 1000G reference. After imputation, SNPs were filtered, based on Mendelian error rate (>2%), a R 2 imputation quality value of <0.80, MAF <0.01 and a difference of more than 0.15 between the allele frequency and the reference (Howie et al., Reference Howie, Fuchsberger, Stephens, ). We tested the effect of different platforms and removed SNPs showing platform effects. This was done by defining individuals on a specific platform as cases and the others as controls. If the allelic association between the specific platform allele frequency and the other platform's allele frequency was significant (p < 10 ?5 ) SNPs were removed. This left 5,987,253 SNPs, which were all used to construct a GRM.