While none of the SRC-1 variant carriers had thyroid function tests suggestive of RTH (high TSH/high FT4, Table 3), interestingly, T4 treatment for autoimmune hypothyroidism of the women carrying the L1376P and A715T variants was complicated by failure to adequately suppress TSH, despite high-dose (> 200 μg) levothyroxine, unless FT4 levels were above 25 pmol/L (normal range, 10-19.8 pmol/L). This evidence concerns the gene NCOA1 and thyroid hormone resistance syndrome.