%0 Journal Article %T Thyroxin-binding globulin deficiency in a boy with fragile X syndrome: a case report %J Reviews in Clinical Medicine %I Mashhad University of Medical Sciences %Z 2345-6256 %A Mirsadraee, Raheleh %A Vakili, Saba %A Abbaszadegan, Mohammad Reza %A Vakili, Rahim %D 2016 %\ 11/01/2016 %V 3 %N 4 %P 171-174 %! Thyroxin-binding globulin deficiency in a boy with fragile X syndrome: a case report %K Fragile X syndromes %K Hypothyroidisms %K TBG deficiency %K Thyroid function test %R 10.22038/rcm.2016.7486 %X Fragile X syndrome (FXS) is the most common known genetic cause of male intellectual disability. A wide variety of medical problems has been reported in FXS syndrome including seizures, facial abnormalities, macroorchidism, and autistic disorders. Here we reported a 9-year-old boy with fragile X syndrome that was confirmed through karyotyping and mental retardation. Initially, he was diagnosed as hypothyroidism when he was 15 months old. However, due to unusual clinical presentation, we re-evaluated the patient according to his history and clinical findings. Subsequently, targeted laboratory tests were performed and the results were indicative for thyroxin-binding globulin (TBG) deficiency in our patient. Therefore, levothyroxine was discontinued and one month later, laboratory tests were repeated and his diagnosis confirmed. As inherited TBG deficiency might also be X-linked, FXS and TBG deficiency may be coincidental findings in the patient. %U https://rcm.mums.ac.ir/article_7486_c32ef9a0612e736303517b306f0e0143.pdf