Supplementary datasets for: Polymorphic short tandem repeats make widespread contributions to blood and serum traits

Short tandem repeats (STRs) are genomic regions consisting of repeated
sequences of 1-6bp in succession. Single nucleotide polymorphism (SNP)
based genome-wide association studies (GWAS) do not fully capture STR
effects. To study these effects, we imputed 445,720 STRs into genotype
arrays from 408,153 White British UK Biobank participants and tested for
association with 44 blood phenotypes. Using two fine-mapping methods, we
identify 119 candidate causal STR-trait associations and estimate that
STRs account for 5.2–7.6% of causal variants identifiable from GWAS for
these traits. These are among the strongest associations for multiple
phenotypes, including a coding CTG repeat associated with apolipoprotein B
levels, a promoter CGG repeat with platelet traits and an intronic poly-A
repeat with mean platelet volume. Our study suggests that STRs make
widespread contributions to complex traits, provides stringently selected
candidate causal STRs, and demonstrates the need to consider a more
complete view of genetic variation in GWAS.