A common genetic variant carried by 1 in 12 South Asians acts as a 'stealth' gene that hides diabetes from standard medical tests.
March 31, 2026
Original Paper
An ancestry-enriched PIEZO1 missense variant biases HbA1c-based diagnosis of prediabetes and type 2 diabetes in South Asians
medRxiv · 10.64898/2026.03.27.26348321
The Takeaway
The HbA1c blood test is the global gold standard for diagnosing diabetes, but this specific mutation artificially lowers the test result without actually lowering the patient's blood sugar. This discovery means that millions of people may be receiving false negatives, delaying critical treatment for a condition they don't know they have.
From the abstract
Background Glycated haemoglobin (HbA1c) underpins type 2 diabetes (T2D) and prediabetes management worldwide and reflects both glycaemia and erythrocyte biology. A missense variant in PIEZO1 (rs563555492T), carried by 1 in 12 South Asians, has been associated with a nonglycaemic reduction in HbA1c. We aimed to further characterise this association and evaluate its clinical consequences. Methods We undertook genetic and linked health data analyses across two cohorts: 19,898 (37.4% female) South I