TUESDAY, Jan. 15, 2019 (HealthDay News) -- The influence of heritability and environmental factors has been identified for a large number of phenotypes, according to a study published online Jan. 14 in Nature Genetics.
Chirag M. Lakhani, Ph.D., from Harvard Medical School in Boston, and colleagues examined the genetic and environmental contributions of 560 disease-related phenotypes in 56,396 twin pairs and 724,513 sibling pairs living in the United States. The contribution of environmental risk factors was estimated in each phenotype.
The researchers found that nearly 40 and 25 percent of the phenotypes studied had a genetic component and were driven at least in part by environmental risk factors, respectively. The greatest degree of heritability was seen for cognitive disorders (four of five diseases), while the lowest degree of genetic influence was seen for connective tissue disorders (two of 11). The highest degree of environmental influence was seen for eye disorders (effect seen for 27 of 42 diseases) and respiratory disorders (34 of 48); the lowest degree of environmental influence was seen for reproductive (three of 18) and cognitive disorders (two of five).
"Our results provide a comprehensive picture of the contribution of genetics and the environment to a large number of phenotypes," the authors write. "Our estimates provide a useful baseline for determining the potential of further genetic and/or epidemiological research for a number of phenotypes of clinical relevance, applicable and complementary to precision medicine efforts."