A rising issue in the world of genetic exploration is the availability and execution of genetic screenings for inherited conditions. One particular group of conditions passed down through generations is heart conditions including long QT syndrome and hypertrophic cardiomyopathy. These conditions are severe and potentially lethal.
When someone is diagnosed with one of these disorders, it is important for immediate family to be genetically tested as well.
The main reason for testing family members is that conditions of this nature can be prevented by catching them early. Although cascade testing, the act of testing a patient for a genetic disorder then proceeding to test family members, is extremely important, it is not often followed through. The purpose of an article published by researchers in January of 2020 was to study the rates of cascade testing for these heart conditions and the reasons they may or may not be carried out.
Researchers analyzed data from six United States pediatric centers for the study. The goals of the study were to examine what circumstances played into the choice of screening and to determine how accurate the screenings were. Both genetic screening and cardiology screening were offered, and the families could choose to go through either or both. The study found that families who were positive for the gene were more likely to go through with the cascade screening than families where the original patient tested negative on the genetic screening. Most families were more willing to go through with the cardiology screening rather than the genetic test. As far as accuracy, the patients who had both screenings done had a higher detection rate for the conditions.
This paper disproved my own biases about the obstacles of genetic testing. I would have thought the largest obstacle would have been insurance because that is a huge issue for genetic counselors on a daily basis. Many insurance companies do not cover genetic testing, and the guidelines for what they will cover are incredibly specific. Contrary to my beliefs, this study actually found insurance to be the least common obstacle for this specific genetic screening at only 6%. The largest barriers were family decisions including lack of follow through and declining both at 26%. There could be many reasons for families deciding to withdraw from or decline testing, but this paper does not go into specifics. Studies like this prove that genetic testing is still a very new field and there are many unknowns. Although these advancements in the genetic field are extremely important, they cannot be an effective route for patients and families until families are more comfortable and knowledgeable about them.
Knight, L.M. et al. 2020. Genetic testing and Cascade screening in pediatric long QT syndrome and hypertophic cardiomyopathy. Heart Rhythm, Volume 17 issue 1, pg 113-114.