ESPE Abstracts

Background: Autoimmune polyglandular syndrome type 3 (APS3) comprises a wide spectrum of autoimmune endocrine disorders other than adrenal insufficiency. It includes the association of autoimmune thyroid disease (ATD) with type 1 diabetes (T1D) which is known as APS3 variant (APSA3v). Genes linked to possible joint susceptibility for APS3v have been reported in few cases. We report a 10-year-old girl with Graves’ disease (GD) who developed T1D after 6 years of the diagnosis.

Case report: A 10-year-old girl was diagnosed with GD at 3-years of age and treated with carbimazole but had frequent relapse when medication was stopped. She was admitted for surgery as definitive treatment rather than radioactive iodine because of an active thyroid eye disease. On admission, she reported classic symptoms of T1D. Investigations revealed a normal cortisol level, HbA1c of 10% and a persistent hyperglycaemia which was well controlled by insulin treatment. Her mother has T1D, and two of her aunts were diagnosed with ATD.

Discussion: In a cross sectional study, 60% of APS3v patients developed GD before the onset of T1D, and 30% developed GD after the onset of T1D; while only 10% of patients developed both simultaneously. Insidious onset of diabetes was more common in APS3v patients who developed GD first, suggesting an influence of GD on the speed of B-cell destruction. A number of genes were reported in association with APS3v, including: HLA class II, CTLA-4, FOXP3, Insulin VNTR, PTPN22 and IL2Rα/CD25 genes.

Conclusion: The reported cases of APS3v with genetic association provide potential illustration of genes linked to joint susceptibly of APS3v, and if these genes could be clustered in certain families or ethnic groups. Our patient has a strong first-degree family history of autoimmune endocrine disorders; therefore, genetic testing was planned for the family.