NGF Blog

Back

Your Guide to Genetic Carrier Screening for Gaucher Disease

Genetic screening for Gaucher disease looks for DNA changes to determine if you are a carrier.

Approximately 1 in 10 Jews of Ashkenazi (Eastern European) descent and 1 in 200 people in the general population are Gaucher disease carriers. As a carrier, you don’t have symptoms or the disease itself—you may not even know you carry the disease. But there’s a chance you’ll pass the Gaucher gene to your child.

“It’s completely normal to be a carrier for a rare disease. Just remember that being a carrier is only half the story when it comes to reproduction. It’s you and your partner put together that determines your chance of having a child affected by the disease,” says Melanie Hardy, MS, CGC, director of genetic counseling for the JScreen program. JScreen, a national nonprofit organization, offers education, screening, and support for many genetic diseases, including Gaucher disease.

The only way to know if you’re a Gaucher disease carrier is to undergo genetic disease carrier screening. While the process can seem overwhelming, knowing your carrier status can help you make decisions about your future.

Why Consider Carrier Screening?

Many reasons might motivate you to find out if you are a Gaucher disease carrier. You may be:

  • A member or descendant of the Ashkenazi Jewish population, which gives you a 1 in 10 risk of carrying the disease
  • Aware of a family history of Gaucher disease and want to factor your carrier status into your reproductive plans
  • Married or partnered with someone who is a carrier or lives with Gaucher disease—prenatal screening can help determine the probability your children will be carriers or affected by Gaucher disease

“It’s a good idea to screen for genetic diseases such as Gaucher before having children, especially if you are at a higher risk of being a carrier,” Hardy says. Knowing your carrier status helps with family planning. It can also highlight an increased risk for conditions associated with Gaucher disease, including a mildly increased risk of Parkinson’s.

Learn about common myths associated with genetic disease carrier screening.

How Screening for Gaucher Disease Works

A Gaucher disease screening test uses a blood or saliva sample to look for mutations in the GBA gene. Everyone has two GBA genes—you received one from your mother and one from your father. If one of those genes has a mutation associated with Gaucher disease, you are a carrier of the disease. Both genes must have mutations to inherit Gaucher disease. Learn more about the difference between Gaucher disease screening and diagnostic testing.

There are several factors to consider in Gaucher disease carrier screening:

Comprehensive screening panel vs. single-gene screening

Genetic tests can look at the genes associated with many conditions, called a screening panel, or target one or a small subset of genes. Most genetic disease carrier screening includes a panel. Some risk factors, such as Ashkenazi Jewish ancestry, increase the risk for many conditions.

“We always recommend comprehensive screening, which looks at many genes,” Hardy says. “A panel can test for more than 200 conditions,” Hardy says. “But the testing for each of those genes is still very detailed.”

Next generation sequencing vs. genotyping

There are two methods used to identify gene variants or mutations:

  • Sequencing, short for next generation sequencing, scans the DNA looking for any changes in the way it is structured
  • Genotyping looks for common gene changes at specific spots along the DNA

Experts including Hardy consider next generation sequencing the gold standard of carrier screening. But she notes that the Gaucher gene is complicated to test. “Very few labs perform sequencing for Gaucher disease,” Hardy says. “But genotyping can provide high detection rates, especially for someone with Ashkenazi Jewish ancestry.” Just eight genetic mutations in the Gaucher gene account for approximately 95% of Gaucher disease carriers in the Ashkenazi Jewish population.

Some people have a family history or increased risk of Gaucher disease and do not have Jewish ancestry. In those cases, sequencing may be better than genotyping for detecting carrier status.

How to Approach Carrier Screening for Gaucher Disease

It’s vital to keep your primary care provider (PCP) in the loop whenever you have concerns about your health. They are familiar with your personal and family health history. Always share new information about your heritage or family, especially if it motivates you to seek genetic disease screening.

“Some doctors are well-versed in genetic diseases and screening and feel comfortable ordering a robust screening panel,” Hardy says. “But not all providers are familiar with the genetics of various conditions found on carrier screens.”

If your doctor seems hesitant or uncomfortable ordering the panel, consider a consumer-initiated genetic testing program such as JScreen. They allow you to initiate the screening process without a physician referral in hand. Before they conduct the screening test, JScreen will reach out on your behalf to your PCP, OBGYN, or other licensed healthcare provider to request the necessary referral.

Clinical genetic testing requires a referral from a state-licensed healthcare provider. But that provider doesn’t have to be a doctor—it can be a genetic counselor, nurse practitioner, or any healthcare provider whose state license permits them to order genetic testing.

Where to Go for Genetic Testing

You can get quality genetic screening through:

  • Outpatient clinical laboratory and testing facilities: If your doctor orders a blood test, you’ll have blood drawn at a local facility, such as Labcorp or Quest Diagnostics. Those services take your blood sample and test it. Your provider can arrange genetic counseling for you.
  • Online genetic testing programs: These services have you collect a saliva sample at home and mail it in for testing in a lab. High-quality online screening programs such as JScreen require a referral from a state-licensed healthcare provider and provide genetic counseling.

The cell type extracted from blood and saliva is the same. But there is more DNA per volume of blood than saliva—though it’s rare, saliva samples may need to be collected more than once. Tests performed in a testing facility and those ordered online take about the same amount of time (three weeks on average) to provide results.

If you pursue at-home testing, Hardy recommends avoiding direct-to-consumer at-home genetic and ancestry testing kits. While these online services use laboratory testing, they often only look for a limited number of variants. The screening process rarely involves healthcare providers, genetic counselors, or health insurance. “If they test for Gaucher disease, they may only look at one or two spots in the gene,” Hardy says. “They are not picking up as much information because they don’t always have the necessary certifications in their lab. It’s not a physician-ordered or clinical-level test.”

Tips for identifying high-quality genetic carrier screening

Whether you’re considering a local lab or online screening service for your carrier screening, Hardy recommends that you:

  • Make sure they perform clinical testing: Clinical-level testing must have a state-licensed healthcare provider involved. High-quality labs are CLIA (Clinical Laboratory Improvement Amendments) certified and CAP (College of American Pathologists) accredited.
  • Look for a lab or program that offers next generation sequencing: Comprehensive screening tests should include some sequencing. A panel may use genotyping for certain complex genes, such as the Gaucher gene. But if the whole panel uses genotyping, the overall detection level will be lower.
  • Ask who will interpret the results: Carrier screening test results are complex, especially for rare genetic conditions. It’s ideal to have genetic counselors or other genetic providers involved in the screening process. They can provide a more accurate interpretation and knowledgeable perspective.

Understanding Your Genetic Screening Test Results

The Gaucher gene can be tricky to test. But it can also be challenging to interpret the results and know what they mean for you, says Hardy.

“Genetic counselors work with these test results daily,” Hardy says. “We know that different variants can mean different things. They don’t all behave the same way.” A genetic counselor can explain how your results might impact your family. They can also connect you with experts specializing in Gaucher disease.

Most reputable testing facilities and programs have genetic counseling staff. The National Society of Genetic Counselors can connect you with telehealth and in-person counseling services.

How the National Gaucher Foundation Can Help

If you or a loved one lives with Gaucher disease, the National Gaucher Foundation is here for your family. We offer resources to optimize your health with Gaucher disease and connect you with the support you need.

 

SOURCES

 

Living a Better Today

Skip to content