Using Extended Genealogy to Estimate Components of Heritability for 23 Quantitative and Dichotomous Traits

• DOI: 10.1371/journal.pgen.1003520
• Publication Date: 2013-05-30T17:02:16Z
• Authors: Noah Zaitlen; Peter Kraft; Nick Patterson; Bogdan Pasaniuc; Gaurav Bhatia; Samuela Pollack; Alkes L. Price
• Keywords: Missing heritability problem; Epistasis; Dominance (genetics)

Important knowledge about the determinants of complex human phenotypes can be obtained from estimation heritability, fraction phenotypic variation in a population that is determined by genetic factors. Here, we make use extensive phenotype data Iceland, long-range phased genotypes, and population-wide genealogical database to examine heritability 11 quantitative 12 dichotomous sample 38,167 individuals. Most previous estimates are derived family-based approaches such as twin studies, which may biased upwards epistatic interactions or shared environment. Our based on both closely distantly related pairs individuals, significantly lower than those studies. We correlations across range relationships, siblings first cousins, find excess correlation these individuals predominantly due environment opposed dominance epistasis. also develop new method jointly estimate narrow-sense explained genotyped SNPs. Unlike existing methods, this approach permits information thereby reducing variance SNPs while preventing upward bias. results show common explain larger proportion previously thought, with present Illumina 300K genotyping arrays explaining more half for 23 examined study. Much remaining likely rare alleles not captured standard arrays.