ESPE Abstracts

Introduction: Thyroid abnormalities such as subclinical or overt hypothyroidism are common in children with Down syndrome (DS) with ranges from 4% to 19.5%, whereas Graves´ disease (GD) is extremely rare (ranges 0.6%-0.9 %).

Aims: To evaluate clinical features, course, and treatment of GD in children with DS.

Patients and Methods: Among 161 children with GD, diagnosed between 1.01.2004 and 31.12.2021 in three tertiary care centres, we identified 13 patients (8 f, 5 m) with DS (8%). Data were collected retrospectively from patients’ medical records.

Results (mean ± SD): GD was diagnosed at a mean age of 10.6 ± 4.5 yrs. (range, 4.1–16.4). The female-to-male ratio was 1.6:1. Eight patients were prepubertal, and five had entered puberty. The most common presenting symptoms were weight loss (n=6, 46%), increased irritability (n=3, 23%), and increased sweating (n=3, 23%). Accompanying diseases were congenital heart disease in two patients, Hirschsprung’s disease in one patient, type 1 DM and celiac disease in another patient. Seven of 11 (63.3%) patients with a thyroid ultrasound at diagnosis had a goitre, no patient had orbitopathy. On admission, all patients had TSH levels <0.01 mU/L (normal range (NR): 0.51-4.30), fT3, fT4 and TRABs were 22.2±10.2 pmol/L (NR: 3.5-8.1), 50.2±18.7 pmol/L (NR 12.6-20.94), and 31.1±42.3 U/L (NR:<1), respectively. Patients were treated either with thiamazole (n=10, 77%) or with carbimazole (n=3, 23%); dose 0.54±0.36 mg/kg/day; two patients received additional beta-blocker therapy. The method of treatment was “block and replace” in 10 patients (77%) and “dose titration” in three (23%) patients, with a mean treatment duration of 43.4±11.0 months. Of 13 patients, four are still receiving primary treatment, three are in remission, one patient had two recurrences both treated medically, three underwent surgery without complications, and two patients were lost to follow-up.

Conclusions: There was no pronounced female preponderance. Our results show that the clinical course of GD in patients with DS was similar to GD in children without DS (data not shown). The majority of our patients responded to prolonged medical therapy; definitive treatment with surgery was performed in three patients.