UNM researchers to offer free DNA testing for New Mexicans who may carry gene for rare neurological disorder

University of New Mexico School of Medicine researchers will spend this coming year offering education and DNA testing to northern New Mexico residents who may be silently carrying a gene that can trigger devastating neurological symptoms.

The condition known as cerebral cavernous malformation (CCM) causes tiny blood vessels in the brain to bleed – hundreds, in some cases – potentially leading to hemorrhage, seizures, neurological disability or even death.

The gene mutation that causes CCM is unusually prevalent among New Mexico families who can trace their ancestry back many generations. Researchers think it first appeared in a Spanish settler centuries ago, said Leslie Morrison, MD, an emerita professor of Neurology who led a Center of Excellence at UNM for the study of CCM and is helping to spearhead the new outreach effort.

“This mutation doesn't exist in Spain, unless somebody moved to Spain after they were born here,” she said. “So, we know that it probably occurred in the New World sometime after the Spaniards arrived. It could have been as early as the late 1500s or early 1600s.”

UNM’s CCM research program was funded for 15 years by the National Institutes of Health. More recently, support from the New Mexico Legislature has enabled the work to continue in partnership with the Alliance to Cure Cavernous Malformation, an advocacy group, Morrison said.

“The purpose of that funding is to build community through education and outreach efforts, but also offer testing for anyone who wants to have DNA testing if they are determined to be at risk,” she said. “We're mostly targeting communities where we know the prevalence is higher.”

Morrison, who first became involved in CCM research in her role as a pediatric neurologist, said the illness sometimes affects children, but it more commonly manifests in middle-aged people as additional brain lesions appear. “If you have the gene, you have a 50-50 chance of passing it on to each of your children,” she said.

There currently isn’t a cure for CCM although the Alliance to Cure Cavernous Malformation is sponsoring research to find treatments, she said. Knowing that you carry the gene may be beneficial, however. Federal health privacy laws prevent health care providers from notifying relatives of those carrying the CCM gene that they might be at risk, so the public outreach effort with the offer of free DNA testing is a way of spreading awareness.

“If we identify someone genetically, we can mostly just be on the lookout,” Morrison said. “For example, if a patient has a bad headache, they should go to the emergency room. This is not something that you can mess around with. You might be having a hemorrhage. They can be proactive in terms of being aware of possible seizure development. That's the point of trying to make sure we've identified people and given them the opportunity to know or not to know.”

Genetic testing sometimes comes with complications, she said. “Once you know that your child has inherited the gene mutation, then you have to deal with the consequences of knowing and whether you tell your child or not and how it might change your relationship as a parent with your child.”

The DNA testing involves a simple swab from the inside of the cheek and it does not confirm a definite diagnosis. The research team hopes to offer the tests at public gatherings around northern New Mexico in coming months, Morrison said.