As a Singaporean-Chinese teenager growing up in London, the following situation is all too common. You're at a party. Two sips into a drink and your eyelids turn bright red, followed by your cheeks, and then your heart starts racing, and eventually nausea, while everyone around you looks completely fine. For roughly 540 million people worldwide, predominantly of East Asian descent, this is a familiar experience. Most people assume it is a sensitivity to alcohol, or perhaps an allergy. However, asian flush is the visible symptom of a genetic variant that disrupts one of the most critical detoxification pathways in the human body, with consequences that extend well beyond an embarrassing blush.