Endocrine Abstracts

Objectives: To evaluate the prevalence and characteristics of thyroid diseases in children with Turner syndrome (TS).

Methods: This is a retrospective study, analyzing clinical data from medical records of 19 patients with TS from 3 to 17 years (average age 12.02±4.0 years), who were regularly followed-up in the University hospital (Minsk). Depending on the karyotype, 3 groups of patients were identified: the first group with karyotype 45, X (n=8), the second group with mosaic variant 45,X/46,XX (n=3), the third group with structural anomalies of X chromosome (n=8). All patients were evaluated for thyroid function (TSH and free T4) and autoimmunity (anti-TPO antibodies (ATPO)), thyroid ultrasound examination was performed. The results were processed using SPSS.22.

Results: TS was diagnosed in patients with characteristic phenotypic signs according to the results of karyotyping at the age of 3.78±3.48 years. 42% of girls (n=8) had normal thyroid function with TSH level of 2.61±0.76 μIU/ml, 58% (n=11) had subclinical hypothyroidism (TSH – 7.5±1.78 μIU/ml and normal level of fT4). Subclinical thyroid dysfunction was revealed in 66.7% girls with mosaic karyotype (n=2, TSH – 6.36±0.79 μIU/ml), in 62,5% girls with monosomy X (n=5; TSH – 7.45±1.92 μIU/ml), less often (50%, n=4) in girls with a mutation of the X chromosome (TSH 8.14±2 μIU/ml). The prevalence of ATPO positivity was found to be 31.6% (n=6). Most of ATPO positive patients were girls with structural anomalies of the X chromosome (50% of patients, n=4). All patients with thyroid dysfunction are treated with levothyroxine, the average daily dose is 1.07±0.53 μ/kg. There were no changes in the structure and size of the thyroid gland in 68.4% of girls (n=13) according to ultrasound. Sings of autoimmune thyroid disease (AITD) were found in 26.3% (n=5), nodal pathology – in 5.3% (n=1). Ultrasound symptoms of AITD were more common in girls with structural anomalies of the X chromosome (37.5%, n=3).

Conclusions: Our data showed high frequency of subclinical hypothyroidism in girls with TS. Thyroid autoimmunity in TS patients is more often detected in the presence of structural anomalies of the X chromosome.