[Genetic deficiency of thyroxin-binding protein in 4 members of a family (author's transl)]

Four members of the same family (2 male and 2 female) with normal thyroid function were found to have decreased total T3 and total T4, elevated response to the T3 test and low free thyroxin index. Such biological changes result from a deficiency in carrier protein and should be distinguished from nearly similar abnormalities observed in low T3 syndrome and hypothyroidism. Whilst gonosomal transmission through the X chromosome of thyroxin-binding protein deficiency seems well established, our findings show that another mechanism, i.e. dominant autosomal heredity, is practically certain.