Gene responsible for some pregnancy-related cardiomyopathies pinpointed

8th January 2016

Researchers in America say they have pinpointed a genetic cause of pregnancy-related cardiomyopathy.

The researchers, from the Perelman School of Medicine at the University of Pennysylvania, say many cases are caused by genetic mutations in their TTN gene, responsible for making the titin protein.

This is the largest protein in the body and directly affects the heart’s ability to contract and relax. Such mutations are also known to cause dilated cardiomyopathy.

The findings are published in this week’s New England Journal of Medicine.

The researchers were investigating other inherited causes of cardiomyopathy when they came across the link.  They analysed 43 genes in 172 women who had had pregnancy-related cardiomyopathy, called peripartum cardiomyopathy.

Twenty six of them (15 per cent) were identified with mutations on the TTN gene, significantly higher than any other reported finding for the cause of peripartum cardiomyopathy, the researchers said.

“Until now, we had very little insight into the cause of peripartum cardiomyopathy,” said the study’s senior author, Dr Zoltan Arany, an associate professor of cardiovascular medicine.

“There had been theories that the condition was linked to a viral infection, or paternal genes attacking the mother’s circulatory system, or just the stresses of pregnancy. However, this research shows that a mutation in the TTN gene is the cause of a significant number of peripartum cardiomyopathies, even in women without a family history of the disease.”

Despite the same gene being affected, dilated cardiomyopathy and peripartum cardiomyopathy are not thought to be the same. A woman with the gene mutation for dilated cardiomyopathy will not always experience peripartum cardiomyopathy, and women with the peripartum cardiomyopathy gene mutation will not always experience dilated cardiomyopathy. How the same mutations can lead to different conditions in different people remains an unanswered question.

But Dr Arany added: “These findings will certainly inform future research, with possible implications on genetic testing and preventive care. Though, more research is unquestionably needed. We’re continuing to follow these women and we’re gathering data for hundreds of others around the world, with the goal of identifying the cause of peripartum cardiomyopathy in the remaining 85 percent of women with this condition, and ultimately using what we learn to improve the care of these women and their newborns.”