The deaths occurred when the children were playing and running around, and one family lost four childrenover an eight year period. Post-mortem examinations failed to identify any known cause of death.
It has been referred to in the Amish community as ‘the curse of sudden death’, according to Michael Ackerman, director of the Windland Smith Rice Sudden Death Genomics Laboratory at the Mayo Clinic, who led research on the cases.
After the first two victims in 2004 the local medical examiner got in touch with Ackerman’s team as they were pioneers of molecular autopsy.
The research team had suspicions that a mutation of a gene called RYR2 might be to blame. Small changes in the RYR2 gene had been linked to other cases of sudden death involving physical exercise linked to cardiac issues. However, the children all appeared to have normal hearts, and no genetic mutations showed up in the initial study.
The case grew cold, but when another two siblings died, researchers realised that with better technology and more advanced tools at their disposal, they might stand a chance of solving the mystery.
The breakthrough came in 2019, and a week ago the findings were published in a report in JAMA Cardiology. The new research once again picked up the thread of the RYR2 gene, and two large extended Amish families with multiple sudden deaths in young individuals from apparent sudden cardiac arrests were included in the study.
The report noted a recessive gene inheritance pattern in young individuals with sudden cardiac arrests, despite unaffected parents.
While the research had originally focussed on a mutation in a base pair in the genes, the use of a special analytical method that detects where entire genes or segments of genes might have been duplicated solved the mystery.
The RYR2 gene was the culprit, but it was not a base pair of genes to blame. It was more than 300,000 base pairs that had been duplicated within the gene. If both parents carry the genetic marker then their children would be at risk from the cardiac issues that had already taken so many lives.
The two families in the study were seemingly unrelated, but as Amish society is particularly tight knit, the appearance of the same genetic defect in two separate families suggests common lineage at some point.
As a genetically isolated population, the Amish have developed unusual health problems from their closed gene pool, and given the close proximity in which they live, it is not uncommon for couples to be related in some way.
While the Amish are known for forgoing modern technology, they do not completely avoid it, especially where it can be so useful. It is hoped that this research will help other families avoid similar heartbreak.
The discovery of this genetic marker allows for testing for the presence of the mutation in individuals. This can potentially save lives as informed decisions can now be made regarding marriage and procreation, thereby helping prevent ‘sudden death’ tragedies from occurring in the future.
For those children that already have the mutation the only option currently available to prevent cardiac issues is an implantable cardioverter defibrillator (ICD), an expensive solution.
Researchers are now working on developing medication in an effort to make treatment more accessible.