deCODE Genetics, which is a research subsidiary of Amgen genomics based in Iceland, has recently created an extremely detailed genetic map. They wanted to uncover more about the human genetic code, much of which has still remained a mystery. We understand that there are two main factors which contribute to DNA- de novo mutations which are not inherited, and genetic recombinations which are. However, the exact pattern of these processes has never been completely understood.
Researchers at deCode believed a high-resolution model of DNA could bring the answers.
deCODE used the whole-genome sequence data of over 155,000 people in Iceland in order to create their model. It had a resolution of 682 nucleotide pairs. Researchers believe this is practically the highest resolution that is theoretically possible to recreate.
With this model they were able to uncover patterns in recombination and de novo mutations by investigating their connection, rate, and location. The most shocking of their findings? That recombinations and de novo mutations are much more tightly linked than we previously understood.
Up until now, most researchers have accepted that de novo mutations occur randomly. But this study contests that.
“In about a thousand bases flanking the sides of recombinations, a mutation rate is increased almost 50-fold.”
This indicates that the formation of new mutations are impacted by crossovers.
deCODE researchers discovered 200,000 new genetic mutations in total and were able to pinpoint the exact location of 4.5 million exchanges between chromosomes. The sites of these exchanges, called hot spots, make up less than 2 percent of the genome.
Some of their other findings include-
- Mother’s age increases recombination rate
- Father’s age does not impact recombination rate
- Females impact recombination more than males
- Males impact de novo mutations more than females
You can read the full study, published in Science here.
What it all Means
Ultimately, the knowledge that de novo mutations and recombinations are related to each other, could help us better understand the genetic mutations which cause rare diseases. By better understanding these mutations, we can better evaluate drug targets for these conditions.
These new findings could help us in the evaluation of therapies for a wide array of diseases.
Slowly but surely we are uncovering the mysteries of the human genetic code, and this new contribution is certainly a big step forward in the progression of our understanding.
You can read more about these findings and how they could impact rare disease research here.