US Survey Finds 25% of Women, Whose Sons Have MD, Not Aware They May Be Carriers

About 1 in 4 women whose sons have Duchenne or Becker muscular dystrophy were unaware of their carrier status and their own risk of cardiac problems, according to the results of a survey conducted by researchers at the University of Michigan.

The study based on the survey, ”Knowledge of carrier status and barriers to testing among mothers of sons with Duchenne or Becker muscular dystrophy,” was published in Neuromuscular Disorders.

Duchenne and Becker MD are a spectrum of genetic disorders, characterized by progressive muscle weakness. Duchenne also affects heart muscles (cardiomyopathy) and leads to insufficient respiratory problems. Becker can be variable, but is usually a milder disorder.

Women who have children with these dystrophies may carry a dystrophin mutation but only experience mild muscle weakness. Cardiac abnormalities, however, could range from mild to severe, making the identification of carrier status of importance for their personal health, and for reproductive health.

Researchers surveyed 182 women who were carriers for Duchenne and Becker in an effort to: 1) estimate the rate of carrier testing in women who have a son with either disease, 2) evaluate their understanding of risks to give birth to another child with these dystrophies and of their own risks of cardiac disease, and 3) assess the barriers to carrier testing and risk awareness. The women were part of the DuchenneConnect patient registry in the U.S.

Survey data showed that around 25% of respondents were unaware of their carrier status, and 14% did not think themselves to be at risk. Among those not being screened for cardiac disease, high testing costs was the most common reason given.

Women unaware of their carrier status were also 13 times less knowledgeable of their cardiac risk, and 37% of them had never had heart ultrasound (echocardiogram).  In contrast, women aware of their carrier status were twice as likely to be tested for cardiac problems in the past five years, the survey showed.

Researchers suggest that reduced testing costs could improve screening for women at risk, and increase their awareness of their carrier status.

“Parent Project Muscular Dystrophy has formally launched a Carrier Initiative to focus on the needs of female carriers. Also, DuchenneConnect will continue to provide genetic counseling support for women who are carriers or at-risk to be carriers, and explore methods to improve access to carrier testing. This includes identifying ways to subsidize the cost of carrier testing,” the researchers wrote.

“These efforts may ensure that more women can access all their healthcare options, as well as improve screening adherence.”