A study of feasibility for genome-wide haplotype association of complex traits in imaging genetics

Imaging-genetics cohorts allow to find associations between genotyped variants and brain imaging features. They are invaluable tools to evaluate the part of genetics and environment in the brain characteristic variance observed in normal and pathological populations. The present analyses were conducted using the 2018 UK Biobank (UKB) data release, and included 15,040 subjects for which sulcal opening, a measure of sulcus width, are extracted for 126 sulci using BrainVisa/Morphologist pipeline. Based on genetic maps, continuous blocks of high-confidence phase are extracted using the haplotype dataset of UK Biobank. The feasibility study analyzes 13,942 haplotypes of 1,756 blocks on chromosome 21, obtained with a stringent block definition, and shows that block-based test seems underpowered compared to haplotype-based association test.