The twentieth century saw the beginnings of understanding and mapping the human genome. This huge leap forward in understanding human DNA led to a far more in-depth understanding of the genetic component underlying many states of human disease once well into the twenty-first century. However, the complexity of the human genome is vast, and the specifics are still very much out of reach. Scientists have realized, however, that often it is not so simple as pointing to a gene and labeling it as a disease-specific-culprit. Rather many human diseases have what has come to be termed as polygenic underpinnings. This mouthful merely means that many genes, in fact, thousands at a time, can contribute to a disease pattern or tendency. Each gene may in fact carry only a small piece of the overall disease pattern or tendency. What all this means, in the end, is that scientists can quantify to some extent genetic heritability as regards a disease. It is also possible to calculate a genetic score based on one’s polygenic load. This number can be used to ascertain reasonable risk, genetically speaking. It is not, however, a predictor of the disease.
Key Takeaways:
- Scientists now know that medical issues affected by DNA are most often not the product of a single gene.
- Rather, thousands of genes with inherited data create the medical tendency together, each only contributing a small part.
- This grouping of many genes, carrying small DNA packages yet impacting on a large scale together, is called a polygenic underpinning of a condition.
“We can now quantify the overall genetic contribution (heritability) and identify specific genetic variants that contribute to the risk of these diseases.”
