MONDAY, Jan. 14, 2019 (HealthDay News) — Two of every five common diseases are at least partially influenced by a person’s genetics, the largest U.S. study of twins ever conducted finds.
Nearly 40 percent of 560 different diseases have a genetic component, while 25 percent are driven by environmental factors shared by twins who are growing up in the same household, the researchers reported.
Brain disorders were most strongly influenced by genetics, the investigators found, with four of five cognitive diseases having a genetic component.
On the other hand, eye diseases and respiratory disorders were most likely to be influenced by the environment in which twins were raised, the results showed.
This report could serve as a roadmap for people interested in studying the causes of any of the 560 diseases considered by the investigators, said lead researcher Chirag Lakhani, a postdoctoral research fellow at Harvard Medical School.
It can be costly and time-consuming to perform studies that feature a full genetic analysis (“genotype”) of participants, Lakhani said. Scientists might skip this step for diseases that are clearly not influenced by genetics.
“Maybe this disease isn’t worth our investment to genotype if you see within a twin study the genetic role is low,” Lakhani said. “Maybe it’s not worth looking into for a specific population.”
For this study, Lakhani and his colleagues used an insurance claims database from Aetna that included nearly 45 million patient records.
The researchers identified more than 56,000 twins and more than 724,000 pairs of siblings. All patients had been part of the insurance database for at least three years, and the twin pairs ranged in age from newborns to 24 years old….
Take a closer look at all the results on the CaTCH website.
The study was published in the journal Nature Genetics.
Source: Harvard Gazette