The co-occurrence of resistance to thyroid hormone beta (RTHβ) and myotonic dystrophy type 1 (DM1) was observed in a Japanese family. Two mutations, P453A and C36Y, were identified in the thyroid hormone receptor beta (THRB) gene. Whereas family members with THRBP453A exhibited RTHβ, two members with THRBC36Y but without THRBP453A had normal thyroid function. Two members, one with RTHβ and the other without, had a triplet expansion in the dystrophia myotonia protein kinase gene, a hallmark of DM1. The member with both RTHβ and DM1 developed atrial fibrillation at the age of 16 years, suggesting a synergistic impact on the heart.
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References
1.
RefetoffS, BassettJH, Beck-PeccozP, BernalJ, BrentG, ChatterjeeK, DegrootLJ, DumitrescueAM, JamesonJL, KoppPA, MurataY, PersaniL, SamarutJ, WeissRE, WilliamsGR, YenPM. 2014. Classification and proposed nomenclature for inherited defects of thyroid hormone action, cell transport, and metabolism. Thyroid, 24:407–409.
BrookJD, McCurrachME, HarleyHG, BucklerAJ, ChurchD, AburataniH, HunterK, StantonVP, ThirionJP, HudsonT, SohnR, ZemelmanB, SnellRG, RundleSA, CrowS, DaviesJ, ShelbourneP, BuxtonJ, David HousmanDE. 1992. Molecular basis of myotonic dystrophy: expansion of a trinucleotide (CTG) repeat at the 3′ end of a transcript encoding a protein kinase family member. Cell, 68:799–808.
