Cardiac arrhythmias and stillbirth
What was the aim of this study?
Many stillborn babies’ deaths are unexplained, even if there is a post mortem. This study looked at whether a faulty gene could be behind some deaths. Our genes are sections of our DNA. They carry the code that lets the body make specific proteins. A faulty gene can lead to a protein that either doesn’t work or doesn’t work properly, and this can have serious effects in the body.
There are a small number of faulty genes that can lead to a fatal change in the heart beat. We can identify some of these genes because, every year, a small number of teenagers and adults die suddenly and unexpectedly because of an undiagnosed heart problem. And these deaths have been traced to the faulty genes.
This study looked to see whether these genes linked with a faulty heart beat were found in stillborn babies for whom no cause of death could be found with a standard post mortem.
Why is this important?
Faulty genes causing a heartbeat problem called an arrhythmia have been linked to some sudden deaths in infancy, so it makes sense to extend the research to see if they could be a cause of unexplained stillbirths. Faulty genes don’t show up in normal post mortems, and this study used advanced techniques to investigate the babies’ genes.
What happened in the study?
The researchers took DNA from 70 stillborn babies and checked for 12 genes well known for their link to arrhythmias or sudden death from a heart problem and for another 23 genes that may also affect the heartbeat.
What did the study find?
Four babies were found to have faulty genes that could have been linked with their death. More than half of the remaining babies had at least one fault in the genes that were looked at, but the possible effect of the fault on their health wasn’t clear. None of the faulty genes was more common in the stillborn babies than in comparison DNA samples randomly selected from a database to match the ethnic mix of the stillborn babies.
The results from this study were published in the Circulation: Genomic and Precision Medicine in January 2018.
What are the conclusions?
Overall, it looks like faulty genes leading to a heart problem may have contributed to a number of these deaths, but it’s very difficult to say this with any certainty.
This type of work is very difficult for several reasons. First, our knowledge about how faults in genes lead to effects in the heart is limited. It is difficult and time consuming to try to recreate the effect of the fault in a laboratory to investigate it. And as these babies had sadly died, it was not possible to see what their heartbeat looked like. There were a low number of babies included in this study because many parents do not want tissue samples from their babies to be used in research. Finally, the researchers did not have DNA from the parents, so couldn’t see if the faulty genes had been inherited, or if a new fault had occurred.
What’s next?
More work is needed to look at how these genetic faults may increase the likelihood of a stillbirth, and whether they are inherited. New genetic techniques and the availability of mapping the genomes of more people mean should help.
An editorial comment on the paper ended:
Stillbirth remains a profoundly challenging experience for millions of patients and families across the world. For now, we should appreciate efforts like those from [the research team] which help refine our understanding of the biology of stillbirth and help frame our next steps.