Hereditary transthyretin amyloidosis (hATTR) with polyneuropathy is a rare, progressive, and life-threatening disease that runs in families. It happens with mutations, or changes, in the transthyretin (TTR) gene that causes a protein called amyloid to build up in the body, leading to issues with the nervous system, heart, and other areas in your body.
hATTR with polyneuropathy affects about 50,000 people worldwide. But experts suggest the number may be higher because the symptoms of this disease are like those of other conditions:
- Tingling, pain, and numbness in your extremities
- Weakness
- Dizziness
- Sexual problems
- Unexplained weight loss
- Urinary tract infections that keep coming back
These symptoms can show up around ages 30 to 70. After they start, people with hATTR may live up to 3 to 5 years, but some estimates say people can survive as long as 15 years.
Genetic testing for the TTR gene mutation that causes the disease may allow for early diagnosis, treatment, and genetic counseling for you and your family. But it may also be emotionally troubling. It can cause:
- Worry
- Anxiety
- Survivor guilt
- Depression
- Denial
For this reason, experts suggest that everyone involved should get emotional support during the genetic testing process. That includes anyone with the gene mutation, people who haven’t taken the test, anyone who has received a negative result, the person showing symptoms, and their family members.
Emotional and Personal Concerns That May Arise Before Genetic Testing
Doctors recommend genetic testing for people over 18 who have been diagnosed with the disease or are thought to have it and for family members at risk who are showing no symptoms. You can also get genetic testing if you have symptoms that might mean you have hATTR.
Because hATTR with polyneuropathy is an aggressive condition that can get worse over time to the point that it's life-threatening, doing genetic testing to know whether you’re carrying the gene causing the disease can be a difficult decision.
Knowing whether you have the mutation can help you get diagnosed and treated early. That can slow down the rate at which the disease gets worse. Still, deciding whether to take the test is up to you. If you don’t, you can still ask your doctor to monitor you for any serious changes in your health. You can also see a genetic counselor and not take the test. Or do the test but not get the results until you need them or feel ready, says Paul Wicks, vice president of neuroscience at Sano Genetics.
How a Positive Diagnosis May Impact You and Your Family
A positive test result means that the lab found that you carry a version of the gene that causes hATTR with polyneuropathy and you’re at a higher risk of getting it. Your family members may want to take the test because they might carry the mutated gene.
“This disease is a chronic medical condition that can affect nerves throughout the body, as well as other organs, and has an impact on quality and length of life,” says Lindsay Zilliox, MD, a neurologist at the University of Maryland Medical Center and an associate professor at the University of Maryland School of Medicine.
“If a person does not have symptoms of the disease when genetic testing is done, this can lead to anxiety about the future,” Wicks says, adding that though testing positive might make you feel anxious or upset, you might also feel empowered to make better decisions about lifestyle and family planning and embracing this aspect of your health as part of your life story
“Because first-degree relatives (your parents, siblings, or children) have a 50% chance of also having a positive genetic test, you might also have feelings of guilt, depression, and anxiety that you’ll pass on the condition to your children,” says Zilliox.
Aaron Baldwin, MS, LCGC, a genetic counselor in the Department of Neurology at the University of Pennsylvania, says getting a result that might explain symptoms you’ve been having, and that other family members may have had, for a long time can be a lot to process emotionally. That’s especially true if you’ve seen many doctors in the past who couldn’t figure out what was causing the symptoms.
It might be scary to share your results with family members, letting them know that they might also be carrying this mutated disease-causing gene, Baldwin says.
Still, Wick says a positive test does not mean 100% that you will get the disease.
How a Negative Diagnosis Can Affect You
A negative test result means that the lab didn’t find gene changes that put you at risk of hATTR with polyneuropathy. You’re also unlikely to get it.
You might feel relief, but also guilt if other family members have a positive diagnosis, Zilliox says.
You can also find a negative result upsetting, especially if it leaves you with unanswered questions about your health. For instance, if you’ve been having symptoms related to hATTR with polyneuropathy, and your test results come back negative, you may need to keep looking for an accurate diagnosis and treatment for your symptoms, Baldwin says.
What to Do if The Genetic Test Comes Back Positive for hATTR
If your results are positive, first, see a neurologist familiar with the disease, Zilliox advises. Because hATTR with polyneuropathy affects many organs in the body, you might also need care from a cardiologist, gastroenterologist, or other specialists, she adds.
Zilliox also recommends you and your family go for genetic counseling. “A genetic counselor will take a detailed personal and family medical history and review any prior genetic testing you or a family member has already had done,” she explains. “They will use this information to determine the likelihood that other family members have the same condition and provide information about the condition and testing options.”
Here, your relatives can decide if they also wish to get tested. And you’ll receive guidance about genetic testing to help you make an informed decision.
Baldwin agrees about seeing a genetic counselor after getting your result. They’ll educate you about how the genetic condition is inherited, the risks of other family members having it, and the symptoms to look out for, he says. They will also prepare you to share the news with your family.
You can also join support groups if you’re comfortable meeting, talking to, and learning from people with hATTR with polyneuropathy. You might find these online at Amyloidosis Support Groups, the Amyloidosis Foundation, and the Amyloidosis Research Consortium.
Show Sources
Photo Credit: E+/Getty Images
SOURCES:
Journal of Patient-Reported Outcomes: “Patient-reported burden of hereditary transthyretin amyloidosis on functioning and well-being.”
Vessel Plus: “Clinical translation of genetic testing in TTR Amyloidosis: genotype-phenotype correlations, management of asymptomatic carriers and familial screening.”
Therapeutics and Clinical Risk Management: “Diagnosis and Treatment of Hereditary Transthyretin Amyloidosis (hATTR) Polyneuropathy: Current Perspectives on Improving Patient Care.”
MedlinePlus: “What do the results of genetic tests mean?”
American Heart Association: “What is hATTR amyloidosis?”
Lindsay Zilliox, MD, neurologist, University of Maryland Medical Center; associate professor, University of Maryland School of Medicine.
Paul Wicks, vice president of neuroscience, Sano Genetics, Lichfield, U.K.
Aaron Baldwin, MS, LCGC, genetic counselor, Department of Neurology, University of Pennsylvania.
