For how we live.
A small crossover trial found 5 mg of melatonin worsened glucose handling and cut early insulin secretion in people carrying the MTNR1B risk variant, but not in non-carriers.
No study shows that eating sugar worsens cancer, phones do not damage genes, and biopsies rarely spread it. A guide to what the National Cancer Institute actually concludes about the most persistent myths.
About a quarter of people sneeze on stepping into bright light. It runs in families, has been tied to specific gene variants, and looks like visual signals spilling into the sneeze circuit.
Men who carry a BRCA2 mutation develop prostate cancer earlier and in more aggressive forms. Trial evidence now supports offering them PSA screening from 40; the case for BRCA1 carriers is weaker.
A protein named after a Greek fate slows ageing in mice and sharpens memory in old monkeys. In people the evidence is a gene variant you are born with, not a treatment.
Low testosterone is a symptom, not a diagnosis. It splits into testicular and pituitary causes — and Klinefelter syndrome, the commonest genetic cause, is found in only about a quarter of the men who have it.
Very long life carries real genetic signals — the APOE gene most robustly, FOXO3 in some populations. But pedigree studies put the true heritability of human lifespan well below 10%.
From LA28, every entrant in an Olympic female-category event is screened for one Y-chromosome gene. Geneticists, including the man who found it, say the test answers a narrower question than the policy asks.
Whole-genome sequencing of 78 families put the figure at two mutations per year of paternal age. A cohort of 40 million US births found small increases in preterm birth and gestational diabetes.
An inactive enzyme carried by an estimated 540 million people lets a carcinogen build up when they drink. In heavy-drinking carriers, oesophageal cancer risk runs many times higher.
A meta-analysis of 27 randomised trials found that disclosing a polygenic risk score did not meaningfully shift diet, screening uptake, medication use, anxiety or cholesterol.
Carriers of loss-of-function MC4R mutations had lower LDL and triglycerides than UK Biobank controls of similar adiposity, and lower cardiovascular risk. The brain sets body weight and lipids separately.