ESPE Abstracts

Introduction: The clinical and genetic characteristics of T1D cases with and without affected family members have been previously studied with varying results. Some investigators found a similarity of presenting features whereas others reported significant differences between the two groups.

Patients and methods: This was a cross sectional descriptive study to determine the clinical presentation and prevalence of beta cell autoimmunity (Anti GAD, anti-islet cell and anti-insulin antibodies), thyroid function (FT4, TSH) and anti-thyroid peroxidase antibody (ATPO) and anti-tissue transglutaminase (ATT) in a cohort of children and adolescent (aged 6 months – 16 years) with FT1DM (n=111), FT1DM was defined as having 2 or more persons affected per family (parent-offspring or sib-pair) and compare them with those for children with non-familial T1DM (n=431) at their first presentation at HMC, Doha, Qatar from 2002–2016.

Results: FT1 DM was more prevalent in boys vs girls (58.5: 41.5 respectively) whereas the prevalence of T1DM did not differ between genders. FT1DM occurred relatively early in childhood (40.7% before the age of 4 years and 72% before 9 years of age). T1DM occurred relatively later in life (80% after the age of 4 years and 40% after the age of 9 years). 35.2% of FT1DM presented with acidosis vs 32.5% of T1DM. The prevalence of anti-GAD antibodies=70.2% in FT1DM vs 75.5% in T1DM. Anti-islet Ab were detected in 53.4% of T1DM and 72.5% of FT1DM. Anti-insulin AB were detected in 40.4% of T1DM and 31.6% of FT1DM. The three antibodies together were high in 18.4% of T1DM and in 16.7% of FT1DM. Anti TPO were detected in 27.2% of T1DM and 35.5% of FT1DM. Hypothyroidism (FT4 <11.5) was detected in 10.6% of T1DM and 2.9% of FT1DM. Subclinical hypothyroidism was diagnosed in 7.3% of T1DM and 2.2% of FT1DM. 22.7% of T1DM and 28.2% of FT1DM had high anti TPO with normal thyroid function. ATT IgA were high in 5% of T1DM and 19.8% of FT1DM whereas ATT IgG were high in 4.4% of T1DM and 15.4% of FT1DM.

Comments and conclusion: It appears that FT1DM is slightly more prevalent in boys vs girls and it occurs earlier in childhood compared to T1DM. Clinical and subclinical hypothyroidism were more prevalent in T1DM vs FT1DM. ATT antibodies were more prevalent in the FT1DM vs T1DM. The genetic background may explain many of these differences.