Myths vs facts: FTO and Fruchtbarkeit

The claim that FTO directly determines fertility is a myth. FTO (fat mass and obesity-associated gene) is strongly linked to BMI and obesity risk (GWAS, human-strong). Obesity can impair fertility through hormonal imbalances, insulin resistance, or inflammation. Some studies suggest weak direct effects of FTO variants on reproductive traits independent of BMI, but the evidence is moderate and inconsistent. Fact: FTO is not a fertility gene. The risk increase is small, and lifestyle factors (diet, exercise, weight) have a much larger impact. A DNA test alone cannot predict fertility. Clinical relevance: the variant is common but not diagnostic. Beware of marketing that labels FTO as a 'fertility gene' – that is an overstatement.