OBJECTIVE Thyroid dyshormonogenesis is a genetically heterogeneous group of inherited disorders in the enzymatic cascade of thyroid hormone synthesis that result in congenital hypothyroidism (CH). Thyroid peroxidase gene (TPO) mutations are one of the most common causes of thyroid dyshormonogenesis. The aim of this study was to identify TPO gene defects in a cohort of patients with thyroid dyshormonogenesis from Slovenia, Bosnia, and Slovakia. DESIGN AND METHODS Forty-three patients with permanent CH and orthoptic thyroid glands from 39 unrelated families participated in the study. Mutational analysis of the TPO gene and part of its promoter consisted of single-stranded conformation polymorphism analysis, sequencing, and restriction fragment length polymorphism (RFLP) analysis. RESULTS TPO gene mutations were identified in 46% of participants. Seven different mutations were identified, four mutations of these being novel, namely 613C > T (R175X), 1519_1539del (A477_N483del), 2089G > A (G667S), and 2669G > A (G860R). Only a single allele mutation was identified in 65% of the TPO mutation carriers. CONCLUSIONS The results showed a higher prevalence of TPO gene mutations in thyroid dyshormonogenesis when compared with published studies. The high percentage of single allele mutations implied possible intronic or regulatory TPO gene mutations or monoallelic expression.

Primary congenital hypothyroidism is a common preventable cause of mental retardation. Neonatal thyroid screening is highly successful in early diagnosis and the improvement of developmental prognosis in the hypothyroid neonate. However, rarely cases could be missed, so doctors must be aware of the earl symptoms and signs of hypothyroidism. Therefore, the purpose of this study was to emphasize the presenting clinical features of primary congenital hypothyroidism at the age of diagnosis. The study population included 17 children with primary congenital hypothyroidism who attended the Department of Pediatrics, University Clinical Center Tuzla between 1986 and 1999. The diagnosis of all patients was confirmed by serum thyroid function tests (T4 and TSH). Of the 17 patients 10 (58.8%) were diagnosed in the first three months of life and 3 of them (17.6%) between fourth and sixth month of life. Four children (23.5%) were diagnosed after the age of six months. In the first three months of life hypothermia, constipation, jaundice, poor feeding, hoarse cry, macroglossia and hypoactivity were the moste common symptoms. Among the 17 patients with primary congenital hypothyroidism 5 of them (29.4 %) were diagnosed to have disgenetic thyroid tissue and 12 (70.6%) as having dyshormonogenesis. TSH and T4 levels were higher in patients in whom thyroid tissue was dysgenetic as comapared with those with dyshormonogenesis but the difference was not statistically significant (p > 0.05). Now it is expected that neonatal screening program in Bosnia and Herzegovina Federation will contribute to the detection of primary congenital hypothyroidism in early days of life. However, until an effective screening test is not yet routine in whole country, paediatricians should consider the diagnosis of hypothyroidism whenever it is clinically suggested.

Thyroid size was estimated by ultrasound and physical examination in 480 schoolchildren (238 boys and 242 girls), 7-14 years old, living in Tuzla Canton. By physical examination goiter was found in 13.5% (n=65) of subjects. When compared with the upper limits of the reference thyroid volumes reported by WHO and ICCIDD, goiter by ultrasonography was found in 12.9% (n=62) of all subjects. All goitrous children had a diffuse goiter. The differences in mean thyroid volumes between groups with and without goiter detected by physical examination were significant in all age groups (p<0.05). The results of ultrasound examinations correlate well with palpatory findings and show higher values for the thyroid volume in children with goiter. It generally confirms the values of the findings by palpation, even in areas with mild iodine deficiency.