Scientists have found a rare genetic condition that runs in large families in Utah, dating back to the 1700s in Denmark.
This dangerous genetic flaw is deemed 'high-impact' as it can put people as young as 13 at high risk for atrial fibrillation (AF). AF, a heart disease that causes irregular heartbeats and sometimes leads to death from blood clots and heart failure, is known as 'high-impact'.
Adults aged 18 and older in Utah had almost an eighty percent chance of developing the disease.
Researchers used an ancestry database to determine the ancestral birth locations of this mutation. They also used family trees to make the maps.
Lynn Jorde, a genetics expert at the University of Utah, said that "The unique partnership between AncestryDNA and the University of Utah Health has broadened our understanding of the human disease,"
This mutation is known as KCNQ1R231H. It has previously been reported in families of Northern European heritage, which seems to increase the risk of young-onset AF.
Although some forms of young-onset AF may not be hereditary, Utah's health records revealed at least five 'apparently unrelated' families.
For example, a 13-year old with paroxysmalAF was discovered to have had a mother who suffered from cardiac arrest and a maternal aunt who died in her sleep in the early 20s.
Genetic sequencing identified the KCNQ1R231 allele in all five families with inherited young onset AF.
The authors state that "looking forward, our results also give a glimpse at how large ancestry data can be used for better understanding the geographical distributions of people at risk of certain genetic diseases, which is a necessary prelude towards precision health care outreach activities."
One Utah family that had the KCNQ1R231H allele consented to having their genetic mutation further tested. Five AF-risk allele carriers in this family consented to their DNA being submitted to the AncestryDNA database.
Researchers eventually found genetic matches in all five people, while 824 people seemed to have the same genetic quirk.
Researchers created an algorithm that tracks these chromosomes over space and time, creating a timeline of possible mutations in the family.
Young-onset AF seems to have originated from their ancestors from Denmark in the 1700s. These ancestors migrated to the Eastern United States from 1800-1850. By the 1900s they were living in Utah.
However, this is not the complete picture. Whole-genome sequencing shows that the KCNQ1R231H allele can be traced back to 5,000 years ago, plaguing around 200 generations. However, our family timelines and genetic databases don't show a much longer history.
Nevertheless, 300 year is still a long time, and enough for researchers to identify individuals in the US who are at risk of developing young-onset AF due to their genes.
The authors conclude that "any genetic variant that increases the risk of a potentially fatal, but treatable condition, provides ample motivation for the development methods to identify at-risk individuals."
"Here is an example of such a technique in the characterization of KCNQ1 R231H and identification of carriers. Although some parts of our method are exclusive to AncestryDNA resources, many of the methods can be used to any large genotype databank.
Nature Communications published the study.
