Down Syndrome Research and Practice 2.2 Pages 67-70

67 Introduction A pathological association between Down syndrome and thyroid disorders was first described by Bourneville in 1903, with subsequent confirmation by others (Hill, 1908; Gordon, 1930). During the last 30 years a clinical association between Down syndrome and thyroid disorders has been established with many reports demonstrating abnormalities of thyroxine (T4), triiodothyronine (T3) and thyroid stimulating hormone (TSH) (Table 1). Case reports of hypothyroidism (Maranon et al, 1951; Aarskog, 1969; Schindler, 1989) and hyperthyroidism (Gilchrist, 1946; Hayles et al, 1965; Blumberg and Ruskin, 1987) in subjects with Down syndrome have been published. The prevalence of hypothyroidism has been found to be greater than that of hyperthyroidism; a ratio of 9% to 1.8% was proposed by Kinnell et al (1987).