Objective: Turner's syndrome (TS) is characterized by the absence of an X chromosome or the presence of a structurally abnormal X chromosome in a phenotypic female. It was recently reported that autoimmune thyroiditis (AIT) was found in 38% of white patients with TS, and few studies in this aspect have been conducted in China. The purpose of this study was to determine the frequency of AIT among TS patients and risk factors for development of thyroid dysfunction in Chinese children with TS.
Methods: Serum antithyroglobulin antibody (TgAb), thyroperoxidase antibody (TPOAb) and thyroid function (T(3), T(4) and TSH) of 24 children with TS (mean age 12.9 +/- 2.4 years, range 4.8 - 16.8 years) were assessed. Their karyotype distribution was as follows: thirteen patients with 45, XO kayrotype, eight patients with structurally abnormal X chromosome, two with X mosaic kayrotype and one with 46, XX. Techniques including radioimmunoassy and elctro-chemiluminescence immunoassy were used in this study. All TS children were divided into two groups. Group one was thyroid autoantibodies (TAA)-positive group, the levels of TgAb and/or TPOAb in them were higher than the normal levels (TgAb < 30%, TPOAb < 20%), respectively, and the remaining patients were assigned into TAA-negative group.
Results: Seven of the 24 (29%) patients had higher levels of TgAb and TPOAb than the normal values (< 30% and < 20%). The level of serum TSH [6.1 (3.6-100.0) mU/L] in TAA-positive group was significantly higher than that [3.9 (1.7-7.9) mU/L] in TAA-negative group (P < 0.05). The frequency of hypothyroidism or subclinical hypothyroidism in TAA-positive group (5/7) was higher than that in TAA-negative group (3/17) (P < 0.05).
Conclusion: The positive rate of serum TAA in children with TS was 29%. About 70% TS children with positive serum TAA developed hypothyroidism or subclinical hypothyroidism. The results have provided the basis for regular follow-up assessment of thyroid autoantibodies and thyroid function in children with TS, and these measures are of importance for timely diagnosis of thyroid dysfunction and application of appropriate treatment.