Rare tweaks in single letters of DNA are not as powerful a force in health and in common diseases as scientists hoped, new work suggests.
Common genetic variants contribute only a tiny bit to a person’s risk of developing particular diseases, so researchers have turned to rare variants as a possible explanation for why some people inherit a propensity for heart disease, diabetes or other common ailments. These rare variants, present in a small percentage of people, are thought to affect how genes work. Two separate attempts to link rare variants with disease suggest that they may not affect disease risk more than common variants do.
View the original article here: Rare genetic tweaks may not be behind common diseases