The congenital hypothyroidism: the incidence and clinical features of different forms

Abstract

Background. Congenital hypothyroidism (CH) as the most common hereditary thyroid pathology is a serious social, economic and psychological burden for a family, where the sick child was born, as well as for the society. The purpose of our study was to evaluate the disease incidence and to detect the clinical features of various forms of congenital hypothyroidism in children. Materials and methods. Twenty two medical records of patients with CH (14 girls, 8 boys) aged 1 month to 6 years (experimental group) and 20 healthy children of the correspondent age were analyzed, and the further assessment of their physical and neuropsychological development was conducted. All children underwent the ultrasound examination of the neck region, indirect laryngoscopy; thyroid-stimulating hormone (TSH), thyroglobulin antibodies, free thyroxine (fT4), thyroglobulin tests were also performed. Clinical signs of CH in the neonatal period were estimated according to the Apgar scores. Statistical analysis was performed with the aid of the Statistica 6.0 program. Results. The thyroid dystopia was diagnosed in 59.1 % of cases, in particular: in the hyoid area (5), the root of the tongue (2), submandibular area (2), jugular fossa (1), unspecified (2). The median of TSH in the first stage of screening in children of the main group was 38 mU/l (24.2–122.4 mU/l), in the comparison group — 2.03 mU/l (1.7–2.6 mU/l). The fT4 level ranged from 0.49 to 14.7 pmol/l, on average — 2.37 pmol/l. The number of clinical signs was not dependent on the age neither on the form of hypothyroidism at the moment of diagnosis. With age, children’s development increasingly lags behind those of correspondent age contributing to further development of fine motor delay. In 40.9 % of patients with CH, the relatives suffered from thyroid disease. Conclusions. The thyroid dystopia is the most common among various forms of congenital hypothyroidism (59.1 %). The reliable differences in TSH and fT4 levels were not found in children with thyroid dystopia and those with typically located thyroid gland. The number of clinical signs was not dependent on the age neither on the form of hypothyroidism at the moment of diagnosis and varied from their absolute absence to presence of seven symptoms at the same time. A delayed formation of motor skills, emotional reactions, the components of cognitive activity was observed in children with congenital hypothyroidism. More than one-third of children with congenital hypothyroidism have concomitant somatic pathology. The predominant lesions of any organs and systems and dependence of the nature of comorbidity on the etiology of congenital hypothyroidism were not observed. In 13.6 % of children, the congenital malformations of other organs were found, mainly in patients with congenital hypothyroidism caused by thyroid dystopia.