New genetic test predicts likelihood of obesity
A newly developed genetic test can identify newborns at the highest risk of developing severe obesity, according to a new study published in the journal Cell.
Researchers from Massachusetts General Hospital in Boston, in collaboration with researchers from The Obesity Society, used previously published data to develop a Genome-Wide Polygenic Score (GPS). The obesity GPS research included more than 400,000 participants. The authors developed the GPS using data derived from more than 100,000 participants in the U.K. Biobank, which enrolled participants 40 to 69 years of age from across the United Kingdom and allowed linkage of measurements such as BMI to extensive genetic data.
The authors used those results to optimize the score, which they then validated in several additional populations of adults, adolescents, newborns, and those who had undergone bariatric surgery, according to the study abstract.
Although each of the variations has only a slight effect, by analyzing them together, the obesity GPS has greater predictive power. Middle-aged adults scoring in the top 10 percent of this genetic test have more than a 25-fold greater likelihood of having severe obesity, characterized by a body mass index (BMI) of more than 40 kg/m2, than those in the bottom 10 percent, researchers said. The two groups were separated by an average weight difference of nearly 30 pounds.
Results from the study showed that although a high GPS did not guarantee people would develop obesity and a low score did not rule it out, the score was highly predictive, researchers said. Among a group of more than 3,700 adolescents and young adults without severe obesity followed for an average of 27 years, the authors found that those who had a high score were 12 times more likely to develop severe obesity than those who scored in the lowest 10 percent.
The study demonstrates that a genetic score based on more than 2 million individual variations in a person's genetic code, is highly predictive of developing obesity and its severe metabolic complications.