Minelli C, et al. - Mendelian randomisation (MR) analyses were performed in UK Biobank on 243,316 women using 254 genetic variants for age at menarche, and on 192,067 men using 46 variants for age at voice breaking to determine the causal impact of age at puberty on the risk of post-pubertal asthma in females and males. Researchers estimated an 8% increase in asthma risk for early menarche (<12 years) and an 8% decrease for late menarche (>14 years) in females and a very similar pattern was noted in males, with a 7% increase in risk for early puberty and a 7% decrease for late puberty. They provide evidence for a causal detrimental effect of early puberty on asthma.