Endocrine Abstracts

We report a 9-year-old Caucasian boy with type 1 diabetes mellitus and elevated blood glucose measurements, which did not correlate with apparent normal range HbA1c values. Safeguarding concerns due to raised blood glucose levels were raised at school, but were not pursued due to normal range HbA1c. Haemoglobinopathy screen showed hereditary persistence of foetal haemoglobin (HPFH) giving the falsely reassuring HbA1c levels. Subsequent fructosamine measurement confirmed the true picture of poor glycaemic control.

Method: Case report: serial analysis of blood glucose measurements and HbA1c taken over a two-year period. Haemoglobinopathy screen and fructosamine measurement. Results: Serum fructosamine elevated at 689 μmol/l. Haemoglobinopathy screen showed 27.2% foetal haemoglobin (normal range 0.1–1.5 at this age). Genetic analysis; heterozygous non-deletional HPFH trait.

Discussion/conclusion: Haemoglobinopathies can affect the accuracy of HbA1c measurements. These cases have been reported more commonly in patients of South East Asian, Mediterranean, and African descent. This case reports a 9-year-old Caucasian child with type 1 diabetes and non-deletional HPFH trait. The diagnosis came to light after inconsistent HbA1c levels with respect to blood glucose measurements. Safeguarding concerns raised from school were revisited after high fructosamine levels confirmed poor glycaemic control. This case showed the importance of lateral thinking when standard HbA1c measurement does not reflect the blood glucose results: alternative measurements of glycaemic control should be considered.