Monogenic Diabetes in a Child with Cystic Fibrosis: A Case Report and Review of the Literature

Acute Recurrent Pancreatitis in a Child With INS-Related Monogenic Diabetes and a Heterozygous Pathogenic CFTR Mutation

Given the close anatomical and physiological links between the exocrine and endocrine pancreas, diseases of 1 compartment often affect the other through mechanisms that remain poorly understood. Pancreatitis has been associated with both type 1 and type 2 diabetes, but its association with monogenic diabetes is unknown. Patients heterozygous for pathogenic CFTR variants are cystic fibrosis carriers and have been reported to have an increased risk of acute pancreatitis. We describe a 12-year-old patient with monogenic neonatal diabetes due to a pathogenic heterozygous paternally inherited mutation of the insulin gene (INS), c.94 G > A (p.Gly32Ser), who experienced 3 recurrent episodes of acute pancreatitis over 7 months in conjunction with poor glycemic control, despite extensive efforts to improve glycemic control in the past 4 years. Intriguingly, the maternal side of the family has an extensive history of adult-onset pancreatitis consistent with autosomal dominant inheritance and the proband is heterozygous for a maternally inherited, CFTR variant c.3909C > G (p.Asn1303Lys). Paternally inherited monogenic neonatal diabetes may have promoted earlier age-of-onset of pancreatitis in this pediatric patient compared to maternal relatives with adult-onset acute pancreatitis. Further study is needed to clarify how separate pathophysiologies associated with INS and CFTR mutations influence interactions between the endocrine and exocrine pancreas.

Clinical and genetic features of maturity-onset diabetes of the young in pediatric patients: a 12-year monocentric experience

BACKGROUND

A retrospective observational study was conducted to assess the prevalence of maturity onset diabetes of the young (MODY) in a large paediatric population of Southern Italy newly diagnosed with diabetes. Clinical and genetic features of the identified MODY patients were also described.

METHODS

Genetic testing was performed in children and adolescents newly diagnosed with diabetes who presented autoantibody negativity and fasting C-peptide levels ≥ 0.8 ng/mL. Patients with a low insulin daily dose and optimal glycaemic control after two years from diabetes onset were also investigated for monogenic diabetes, regardless of their autoimmunity status and/or C-peptide levels.

RESULTS

A prevalence of 6.5% of MODY was found. In particular, glucokinase-MODY was the most common type of MODY. The mean age at diagnosis was 9.1 years. Clinical presentation and biochemical data were heterogeneous also among patients belonging to the same MODY group.

CONCLUSIONS

We found a relatively high prevalence of MODY among paediatric patients with a new diagnosis of diabetes in comparison to literature data. Our findings highlight that a more detailed clinical evaluation along with easier and less expensive approachability to genetic testing may allow diagnosing an increasing number of MODY cases. A correct, prompt diagnosis is crucial to choose the most appropriate treatment and offer adequate genetic counselling.