# Clinico-Metabolic Profile and Follow-Up of Familial Cases Compared to Sporadic Cases in a Lyon Series of Type 1 Diabetic Children

## TL;DR

This study compares children with familial type 1 diabetes to those with sporadic cases and finds that familial cases have less severe initial symptoms, with differences between paternal and maternal inheritance.

## Contribution

The study identifies distinct clinico-metabolic profiles between familial and sporadic type 1 diabetes in children, with a focus on parental inheritance differences.

## Key findings

- Familial T1D children consulted earlier and had lower initial HbA1c and insulin requirements.
- Children with a T1D father had worse glycemic control at 10 years compared to those with a T1D mother.
- Long-term outcomes were similar between familial and sporadic T1D cases.

## Abstract

Objective: This study aimed to describe the clinical, biochemical, therapeutic, and progressive characteristics of children with familial type 1 diabetes (T1D) compared to those with non-familial T1D. Compare within the first group, the phenotype of type 1 diabetics inherited from the father with those inherited from the mother.

Patients and methods: We conducted a retrospective study lasting 10 years at the L'hôpital Femme Mère Enfant (Woman-Mother-Child Hospital) in Lyon, France. Cases were any child diagnosed with T1D for at least 12 months who had a parent with T1D. Each case was matched with a T1D control without a family history of T1D, of the same age, same sex and same year of discovery. Cases group was divided into two subgroups according to the sex of the parent with T1D.

Results: A total of 43 children had a TD1 parent (family group) of whom 27 cases were the father. Forty four T1D children without any T1D parent were matched (sporadic group). The family group had consulted earlier (p < 0.001), were less in initial diabetic ketoacidosis (p = 0.016), and had a lower HbA1C level lower (p < 0.001) and lower initial insulin requirements (p < 0.001). During follow-up, it was noted that the evolution of Hb1AC, insulin requirements, and chronic complications were similar in familial and non-familial cases (p = 0.943, p = 0.450, p = 0.664, respectively). The patients in the T1D mother group seemed better balanced than those of the T1D father with an average HbA1C at 10 years of follow-up of 7.82% in the maternal group compared to 9.10% in the paternal group (p = 0.021).

Conclusion: This study shows that familial T1D is a protective factor against the initial severity of T1D in offspring. Paternal T1D presents a more severe initial and progressive clinico-biological character than T1D inherited from the mother. However, during follow-up, other psycho-environmental factors could modify this observation.