Lavard L, Ranlov I, Perrild H, Andersen O, Jacobsen BB. Incidence of juvenile thyrotoxicosis in Denmark, 1982-1988. A nationwide study. Eur J Endocrinol 1994;130:565–8. ISSN 0804–4643 The objective of this study was to ascertain the annual incidence density of thyrotoxicosis in children under the age of 15 years in Denmark in 1982–1988. The design was based on computerized hospital registration of patient admittances in all departments of paediatrics and internal medicine of Denmark (Faroe Islands and Greenland excluded). Fifty-six children (48 girls and 8 boys) had a confirmed diagnosis of thyrotoxicosis, giving a national incidence density of 0.79/100 000 person-years. In children aged 0–4 years the incidence was very low (0.1/100 000), with no sex difference. In boys aged 5–9 years a similar low incidence was found, while in boys aged 10–14 years the incidence increased to 0.48/100 000. In girls aged 5–9 years the incidence increased to 0.96/100 000, reaching a maximum of 3.01 in the 10–14-year-old girls. In children of > 4 years of age a female preponderance of 6.7:1 was significant. It is concluded that thyrotoxicosis is a rare disorder in Danish children under the age of 15 years, and the incidence increases with age. Female preponderance is significant from early childhood. Lene Lavard, Department of Paediatrics, Hvidovre University Hospital, DK-2650 Hvidovre, Denmark

A 18-year clinical follow-up period in a male patient with a germline TSH-R gene mutation (Met453Thr) is described. Nonautoimmune thyrotoxicosis was diagnosed at the age of 7 months. The patient had exophthalmus, failure to thrive, advanced bone age and no goiter. Long-term antithyroid drug treatment (ATD) was necessary during childhood. At the age of 7 years he developed a goiter. Subtotal thyroidectomy was performed at the age of 9 years, followed by repeated ablative radiotherapy at the age of 9.5–13 years due to a toxic multinodular goiter. After 13 years ATD could be discontinued and the patient was euthyroid until 16 years of age, where L-thyroxine substitution had to be started. The exophthalmus diminished, and had disappeared at the age of 18 years, when CT scan of the orbit was performed. Conclusion: TSH-R mutation must be considered in early nonautoimmune thyrotoxicosis. A very agressive treatment strategy is necessary.

Previous studies have shown that HLA-DRB1*0301 and DQA1*0501 are associated with susceptibility to Graves' disease. Ninety Danish patients with early onset of Graves' disease and 102-192 controls were analyzed for HLA-DR and -DQ to investigate if the same associations exist in the juvenile form of Graves' disease. Both DRB1*0301 and DQA1*0501 were highly significantly increased in the patients with relative risks of 8.0 and 4.6, which are higher than those seen in adults. Stratification showed that DRB1*0301 is more strongly associated than DQA1*0501. Surprisingly, the DRB1*0701,DQA1*0201 haplotype was completely absent from this group of patients, indicating a strong protective role of this haplotype in juvenile Graves' disease.

Aim: To ascertain the prevalence of germline mutations in the TSH receptor gene as a cause of juvenile thyrotoxicosis (JT) in non‐autoimmune patients. TSH receptor gene mutations are not seen in autoimmune‐active patients. Methods: In a nationwide study on JT, 123 patients were re‐examined 10 y (range 4 to 21 y) after diagnosis. Two patients with toxic adenoma were excluded. In 25 patients, no TPO, TG or TSH‐R antibodies were found. In 17 patients, DNA material was available for TSH receptor gene analysis. The entire TSH receptor gene was sequenced in five patients. TSH receptor “hot spots” for mutations in exon 9 and 10 were sequenced in the remaining 12 patients. Results: A TSH receptor gene germline mutation was identified in only one patient of a total number of 121 patients with JT, of which 17 patients were presumed to have non‐autoimmune JT by the lack of thyroid autoantibodies. Conclusion: In Denmark the prevalence of germline mutations in the TSH receptor gene is one in 121 patients with JT (0.8%; 95% CI: 0.02–4.6%) and one in 17 patients with presumed non‐autoimmune JT (6%; 95% CI: 5.88% (0.15–28.69)).

Many JGD patients were euthyroid at the long-term follow-up in spite of high TPO ab and Tg ab titers. Stimulating TSH-R ab were rare (13%). According to this presence of TPO ab, Tg ab or TSH-R ab does not predict the final outcome of JGD. Further studies are needed.