We compared participants with two alleles of each HLA type to those with no alleles; participants homozygous for HLA-DQA1*03:01 have 19.3% (OR 1.19, 95% CI 1.10–1.30, p = 2.84*10–5) increased likelihood of sarcopenia, compared to those without HLA-DQA1*03:01 (Supplementary Table 4) and HLA-DRB4*01:03 homozygotes had a 15.4% increased likelihood of sarcopenia (OR 1.15, CI 1.08–1.23, p = 2.66*10–5). This evidence concerns the gene HLA-DQA1 and sarcopenia.