In the past, geneticists had identified 17 genes underlying long QT syndrome. According to ClinGen experts, there may be far fewer. The researchers analyzed the evidence brought by previous studies, questioning the validity of some of these. From what emerges in the new study, only 3 of the 17 genes would be associated with the most common form of the disease.
It all began 20 years ago, when the New York Times reported the case of three boys who died for no apparent reason. Subsequent studies shed light on a semi-unknown heart disease, which killed around 4,000 young people in the United States in 2019 alone. According to the researchers, the deaths are said to be caused by mutations in the genes that regulate the electrical activity of the heart. All of a sudden, the muscle begins to beat irregularly or stops completely, killing the person.
Long QT syndrome often remains without a diagnosis, unless there have been other cases in the family. In such cases, experts recommend a genetic test for all the victim's closest relatives. This is where the study in question intervenes, which classifies and analyzes the 17 genes traditionally linked to the disease. According to the analyzes, the genes that explain most of the cases are only three: KCNQ1, KCNH2 and SCN5A.
Another 4 genes are linked to a form of the disease found only in infants. The other 10 genes, on the other hand, seem almost completely disconnected: according to the researchers, there is insufficient evidence of their actual role in the disease.
The discovery could improve both the understanding of the disease and its early diagnosis.