Which make the effects of mutations harder to predict than hoped. Of course, it’s also a blow for genetic determinism.
Ever since the decoding of the human genome in 2003, genetic research has been focused heavily on understanding genes so that they could be read like tea leaves to predict an individual’s future and, perhaps, help them stave off disease.
A new USC Dornsife study suggests a reason why that prediction has been so challenging, even for the most-studied diseases and disorders: The relationship between an individual’s genes, environment, and traits can significantly change when a single, new mutation is introduced.
“Individuals have genetic and environmental differences that cause these mutations to show different effects, and those make it difficult to predict how mutations will behave, ” said Ian Ehrenreich, a lead author and biologist at the USC Dornsife College of Letters, Arts and Sciences. “For example, mutations that break the cell’s ability to perform DNA mismatch repair are linked to colorectal cancer, but some individuals that harbor these mutations never develop the disease.”
A growing number of large-scale, genome-wide association studies have revealed which genes are linked to certain diseases, behaviors or other traits. These studies overlook how interactions between genetic differences, the environment, and new mutations — what scientists have termed “background effects” — differ from individual to individual.
“Mutations that behave unpredictably are most likely quite rare. However, that makes them difficult to detect and measure in those studies,” Ehrenreich said.Paper. (open access) – Martin N. Mullis, Takeshi Matsui, Rachel Schell, Ryan Foree, Ian M. Ehrenreich. The complex underpinnings of genetic background effects. Nature Communications, 2018; 9 (1) DOI: 10.1038/s41467-018-06023-5 More.
See also: New goal: 66k animal genomes to be mapped Given how much genome mapping has done to debunk straightforward Darwinism, just from the genomes released to date, however complete, one can only guess at what all 66k would do.
There’s a gene for that… or is there?