C9orf156 (encoding TRNA Methyltransferase O) was implicated by a single putative causal tolerated missense variant, rs2282192 (T allele, frequency 28.8% in EUR), associated with increased TSH, increased hypothyroidism risk and decreased risk of nontoxic multinodular goitre and thyroid cancer as well as lower mean corpuscular volume and HbA1c. Here, TRMO is linked to hypothyroidism.