Fig. 1.

a Pedigree of the family with TFTs and THRB variant. TFTs are aligned below each symbol representing a family member. Abnormal values are shown in bold. The proband is indicated with an arrow. Square symbols indicate males, circles females. Roman numerals to the left of the pedigree indicate the generation and Arabic numerals to the right of each symbol individual family members. Half-filled symbols indicate subjects heterozygous for the novel THRB mutation, as indicated in the legend. b Schematic representation of the thyroid hormone receptor beta (TRβ) and its functional domains, showing the location of amino acid 385 within the cold region. FT4I, free thyroxine index; LT4, levothyroxine; TFTs, thyroid function tests; TGab, thyroglobulin antibodies; THRB, thyroid hormone receptor beta gene; TPOab, thyroperoxidase antibodies; TrT3, total reverse triiodothyronine; TSH, thyroid-stimulating hormone; TT3, total triiodothyronine; TT4, total thyroxine; WT, wild type.