Despite that research, a new startup is claiming that it can determine the likelihood that someone is gay by analyzing the results of commercial DNA tests like 23andMe or MyHeritage. Instead, there are a series of genetic markers that help to influence a person's sexual identity, and there is no definite indicator of someone's sexual preferences based on DNA. Earlier this year, a groundbreaking study that looked at the genetic makeup of more than 500,000 people determined there is no singular 'gay gene' that serves as a reliable predictor of a person's sexuality.