ESPE Abstracts

Background: Trisomy 21 is a chromosomal abnormality that predisposes to autoimmune diseases. Among them the thyroid dysfunction is frequently observed.

Objective and hypotheses: Study the various thyroid diseases in trisomy 21 patients and their therapeutic management.

Method: This is a retrospective study of 50 cases of Down syndrome children with thyroid disease, collected over a period of 9 years (2006–2015). All children underwent a complete physical examination, a thyroid balance (FT₄ and FT₃ or -TSH TPO and anti us- AC or TSI) and a cervical ultrasound.

Results: There are 34 boys and 16 girls. The mean age of diagnosis of thyroid dysfunction was 4 years (20 months–15 years). It was hypothyroidism in 46 cases and hyperthyroidism in four cases. The discovery of hypothyroidism was made on the occasion of a systematic review in 36 cases before signs of hypothyroidism in ten cases. Hypothyroidism was compensated in 78% with an average rate of 17 pmol/l FT₄ and TSH 8.5 μUI/ml. The anti-thyroid peroxidase antibodies were positive in half the cases with aspect of thyroiditis at cervical ultrasound. Treatment with L-thyroxine quickly led to the normalization of TSH. Hyperthyroidism was discovered following a tachycardia and eye signs. Hormonal balance showed low TSH (<0.01 μUI/ml) and high FT₄ (mean 40 pmol/l). Cervical ultrasound revealed a thyroiditis aspect with anti TPO AC positive. There was not visceral or metabolic complications. The initiation of treatment with antithyroid drug led to a definite hypothyroidism.

Conclusion: Thyroid disease is common in children with Down syndrome 21. Hypothyroidism is more common. a systematic monitoring of thyroid function is necessary.