A genetic variant prevalent in black and Asian men can distort HbA1c test results and delay type 2 diabetes diagnosis for years, researchers warn.

Their study found that glucose-6-phosphate dehydrogenase (G6PD) deficiency, the result of a hereditary genetic mutation, was present in one in seven black men and one in 63 Asian men compared with fewer than one in 10,000 white men.

Despite this, fewer than 1.1% of black carriers and less than 2.9% of Asian carriers had it recorded in their health records.

The study analysed data from 467,368 patients across two UK datasets using whole-exome sequencing to identify patients with G6PD deficiency.