Genetics What are the two main sources of genetic variation?
What are the two main sources of genetic variation?
The two main sources of genetic variability are mutations and repeated combinations of genes as a result of reproduction.
Mutations and combinative variability. Also, according to recent studies, there may be epigenetic mechanisms of inheritance as a result of modifications.
@morphism In medicine, several examples of the interaction between genes and environmental factors have been described, in particular, the effect of the interaction between genetic variants in HLA and smoking in the development of autoimmune diseases. Thus, when studying the population of patients with rheumatoid arthritis, it was revealed that smokers with a certain allele of the HLA-DRB1 gene have a much higher risk of seropositive disease than non-smokers or smokers without this allele. A similar effect of the interaction of smoking with the HLA-A*02 and HLA-DRB1*15 alleles has been shown in relation to the risk of multiple sclerosis. The presence of interaction between genes and environmental factors helps to explain the relatively low effect of genetic variants as risk factors for complex human diseases: studies of genetic factors without taking into account environmental effects do not take into account the synergistic effect and do not describe the interaction.