UK researchers have proposed a biomarker-screening pathway that can improve the diagnosis of monogenic diabetes in children without relying on clinical features.
Based on their study of more than 800 patients, the Exeter group concluded about 2.5% of the paediatric diabetes cases in the UK were monogenic diabetes.
Importantly, they estimated about half of those patients were likely to be misdiagnosed.
Australian experts agreed that while awareness of monogenic diabetes had increased significantly in the last 10-15 years, there were still cases being missed and those patients were receiving ineffective treatment.
Professor Fergus Cameron, from the Murdoch Children’s Research Institute, said there was now a high degree of awareness of monogenic diabetes in the paediatric endocrinology community.
“In practice when a child presents with diabetes, our initial assumption will be type 1 diabetes as it is the most common diagnosis and also the most dangerous,” he said.
However red flags including family history and an atypical response to insulin were usually apparent by the time the autoantibody status was confirmed, he said.
The UK group found a two-step screening process – a positive urinary C-peptide creatinine ratio followed by a negative islet autoantibody test – identified a target group of 10% of their clinic population for genetic testing.
One in four patients referred for genetic testing were identified with a known mutation including GCK, HNF1A, HNF4A, HNF1B, ABCC8 and INSR.
Professor Tim Jones, from the Princess Margaret Hospital for Children in WA, said the C-peptide screening step was a useful suggestion and not just for children with type 1 diabetes.
“We are certainly missing cases and can also sometimes assume type 2 diabetes if the patient is obese,” he said.
“This is an important study reminding us that monogenic diabetes is prevalent.
Patients with HNF forms of the disease can be treated simply with sulphonylurea tablets while patients with GCK don’t need treatment at all.”
“Accurate diagnosis is therefore important to reduce the costs for the patient and the community.”
The study was published in Diabetes Care.