ESPE 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 167 patients with TS from 3 to 18 years, who were regularly followed-up in the University hospital (Minsk). Depending on the karyotype, 4 groups of patients were identified: the first group with karyotype 45,X (n = 83), the second group with mosaic variant 45,X/46,XX (45,X/47,XXX/46,XX, 45,Х/47ХХХ) (n = 23), the third group with isochromosome iXq (n = 23) the third group with other karyotypes (n = 38). 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 9.8 [3.8-12.8] years. 55.1% of girls (n = 92) had normal thyroid function with TSH level of 2.72 ± 0.74 μIU/ml, 36.5% (n = 61) had subclinical hypothyroidism (TSH - 7.12 ± 1.68 μIU/ml and normal level of fT4). Overt hypothyroidism was diagnosed in 6.0% (n = 10) patients, hypothyroxinemia - in 1.8% (n = 3) girls, secondary hypothyroidism in one child (0.6%). Mean age at thyroid dysfunction diagnosis was 10.7 [7.7-13.3] years. The largest number of patients with normal thyroid function was noted in the group with monosomy X (66.3%). The prevalence of ATPO positivity was found to be 32.9% (n = 55). Most of ATPO positive patients were girls with isochromosome iXq (39.5% of patients, n = 15). Patients with elevated anti-TPO antibodies showed statistically significant differences in the incidence of thyroid hypofunction (65.5%) in comparison with girls with normal anti-TPO antibodies (35.2%) (χ² = 12.3; P <0.001).There were no changes in the structure and size of the thyroid gland in 38.7% (n = 29) of girls with thyroid dysfunction according to ultrasound. Sings of autoimmune thyroid disease (AITD) were found in 36% (n = 27), thyroid hypoplasia - in 20% (n = 15).

Conclusions: Our data showed high frequency of thyroid function in girls with TS (44.9% of patients). Subclinical hypothyroidism is the most common manifestation of thyroid dysfunction in children with TS. Thyroid autoimmunity in TS patients is more often detected in the presence of isochromosome iXq.