Extended Data Fig. 1: CAG trinucleotide repeat expansions in UK Biobank (n = 490,416).

a, Types of short-read evidence of repeat alleles of different lengths. b, Fifteen CAG repeat loci at which at least five UKB participants carried long alleles (≥ 45 repeat units). Repeat expansions in genes highlighted in red are known to be pathogenic. For each locus, the length distribution of common short alleles (≤ 30 repeat units) is shown; the length range is indicated below each histogram, red bars denote interrupted repeat alleles, and blue bars denote alleles with alternate flank sequences. For each common allele between 10–30 repeat units, estimated rates of intergenerational expansion and contraction (by ±1 unit) are plotted as a function of allele length; the mutation rate of the longest plotted allele is indicated at the end of each curve. For long alleles, counts of UKB participants with at least one in-repeat read (IRR) or IRR pair are shown.