Gene test may be needed for diabetes type 2
Wednesday September 13th, 2017
Genetic screening may be needed to identify people at raised risk of type 2 diabetes, researchers reported last night.
Many genetic variants significantly impact the results of the HbA1c blood test used to diagnose the condition, so a team from the Wellcome Trust Sanger Institute, Cambridge, UK, took a closer look.
Along with an international team of more than 200 scientists, the Cambridge team carried out the largest study of its kind. They studied genetic variants in almost 160,000 diabetes-free people from European, African, East Asian and South Asian ancestries, followed over time.
This highlighted 60 genetic variants that influence the outcome of HbA1c tests, of which 42 were new. One in particular was found to significantly impact the results of the HbA1c test - the G6PD genetic variant. It is almost unique to people of African ancestry, report the researchers, with about 11% of African Americans carrying at least one copy.
They reported in PLoS Medicine yesterday (12 September) that: "We found that the more glycaemic variants a person had, the higher their risk to get diabetes."
They add that variants which lower HbA1c levels independently from glucose concentration could lead to missed diagnosis of diabetes.
They conclude: "As a G6PD deficiency can be clinically silent until illness strikes, we recommend investigation of the possible benefits of screening for the G6PD genotype along with using HbA1c to diagnose type 2 diabetes in populations of African ancestry or groups where G6PD deficiency is common.
"Screening with direct glucose measurements, or genetically-informed HbA1c diagnostic thresholds in people with G6PD deficiency, may be required to avoid missed or delayed diagnoses."
* The NHS is due to get the go-ahead today to offer flash glucose monitoring, according to reports.
Diabetes UK said it would be “fantastic news,” sparing patients from finger-prick testing.
Wheeler, E. et al. Impact of common genetic determinants of Hemoglobin A1c on type 2 diabetes risk and diagnosis in ancestrally diverse populations: A transethnic genome-wide meta-analysis. PLoS Medicine 12 September 2017; doi: 10.1371/journal.pmed.1002383 [abstract]
Tags: Africa | Diabetes | Genetics | UK News | World Health
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