Accompanying extrathyroidal anomalies in patients with congenital hypothyroidism

Introduction - Aim: Congenital hypothyroidism (CH) is a thyroid hormone deficiency that develops due to incomplete development of the thyroid gland or inadequate production of thyroid hormones. Thyroid hormones are critical for neurodevelopment; CH is considered to be the leading cause of preventable mental retardation in children. In this study, it was aimed to evaluate patients, who were followed up for CH, in terms of additional congenital anomalies. Materials and Methods: In the study, a total of 265 patients with CH, who were followed up in the Dicle University Faculty of Medicine Hospital between 2016 and 2023, were included. Sociodemographic characteristics, the results of thyroid ultrasonography, thyroid function tests (TSH, Free T4), abdominal ultrasonography and echocardiography, and information regarding the presence of additional anomalies were obtained from the medical records of the patients and examined retrospectively. Findings: Among the 265 patients included in the study, 106 (40%) were female and 159 (60%) were male. Additional extra-thyroidal congenital malformations were detected in 77 (29.1%) of the 265 patients, while no additional congenital anomalies were found in 188 (70.9%) patients. In the study, it was found that 52 (67.5%) of the 77 patients with detected additional anomalies had cardiovascular system anomalies, 23 (29.9%) had urogenital system anomalies, 14 (18.2%) had gastrointestinal system anomalies and 2 (2.6%) had muscular and skeletal system anomalies. In addition, 6 (7.8%) patients were found to have other system anomalies that were unclassified. Thyroid dysgenesis was present in 22 (8.3%) of the 265 patients included in the study and dyshormonogenesis was present in 243 (91.7%) patients. Patients with thyroid dysgenesis and dyshormonogenesis were compared in terms of the frequency of additional extra-thyroidal malformations. It was determined that there was no significant difference between the groups in terms of anomalies in all examined systems (p <0.05). Patients with CH who had and did not have additional anomalies were compared in terms of thyroid function test results at the time of diagnosis, and the difference was not found to be statistically significant. Conclusion: In our study, associated extra-thyroidal malformations were detected in 29.1% of the patients with congenital primary hypothyroidism. The most common accompanying system anomalies were found to be anomalies of the cardiovascular, genitourinary and gastrointestinal systems, respectively. Our results were consistent with the results of previously conducted studies in the literature, which had shown that extra-thyroidal defects occurred at a higher rate in patients with CH compared to the general population. We believe that screening patients with congenital hypothyroidism for additional system anomalies and performing cardiological examination, echocardiography and abdominal ultrasonography are important to improve the prognosis of the patients. Therefore, we believe that every patient with CH, in whom dysgenesis or dyshormonogenesis is present, should be screened for additional anomalies. Keywords: Congenital hypothyroidism, extra-thyroidal malformations, cardiovascular system