Are You An SMA Carrier?May 01, 2011 by Victoria Strong
Are You An SMA Carrier? It is simple to learn if you are 1 in 40. A simple blood or saliva test will determine if you are a carrier of Spinal Muscular Atrophy, SMA. SMA occurs through autosomal recessive inheritance. Meaning, in general, both parents must be carriers for the baby to have the active form of SMA. Currently, SMA is NOT a standard test and you must request this test from your doctor. Ideally, carrier testing should be done before pregnancy to provide the widest array of options for prevention.
Why Is Carrier Screening Important? The American College of Medical Genetics (ACMG) recommends that all adults of reproductive age who are planning to conceive be offered carrier testing for Spinal Muscular Atrophy. Why does ACMG recommend this? –> 1 in every 40 people UNKNOWINGLY carry the SMA gene. Most have NO family history of the disease and NO signs during pregnancy. 1 in 40!
- That’s one person in every Starbucks.
- That’s 10 people on every jumbo jet.
- That’s over 30 Million people on Facebook.
- That’s nearly 185 Million people around the globe.
- And one of those could be you.
If you and your partner are carriers of the SMA gene, every pregnancy — EVERY SINGLE PREGNANCY — has a 25% risk of having the disease. So even if you already have one…two…five healthy children, you can still have a baby with SMA.
Ask Your Doctor. SMA is not currently a standard test in most obstetrician practices. Talk to your doctor and let them know you want to know if you are an SMA carrier. Because SMA is an autosomal recessive disease, BOTH parents need to be carriers for the active form of the disease to be passed down. But only ONE parent has to be a carrier to pass carrier status on to children. Most major insurers cover preventive genetic testing.
What Are Family Planning Options and Can You Prevent SMA? If SMA testing shows both parents are carriers, speak with your doctor to fully understand all of your options. Family planning when you know you carry a hereditary disease is personal to each couple. Some couples choose to pursue natural pregnancy with the 1 in 25 risk, then have prenatal testing or test at birth to learn if the child has SMA. There are also several choices couples can make to prevent SMA: IVF with PGD (in vitro fertilization using Preimplantation Genetic Diagnosis); pursue pregnancy using donor sperm, donor eggs, or donor embryos; conceive naturally and have prenatal testing, such as CVS early in pregnancy; adoption.
Carrier Screening Resources >> Carrier testing tests YOU and what you can potentially pass on to your child. Carrier testing does not test the baby's individual genetics. 80% of babies born with genetic diseases are born to parents with no family history of that disease. The goal of carrier screening is to give families knowledge before they even conceive! This study, published in the Journal of the American Medical Association (JAMA), found a significant impact of carrier screening in highlighting pregnancies at risk of serious conditions across all ethnicities.
Counsyl offers a blood or saliva-based test which screens for 100+ serious genetic diseases, such as Cystic Fibrosis, Tay-Sachs, and Spinal Muscular Atrophy. The test cost is relatively low with or without insurance. This is the most cost effective option to screen for 100+ serious genetic diseases. Tell your OBGYN that you specifically want the Counsyl test so they can register their practice. Results will be emailed to you within two weeks and genetic counselors are provided to discuss your results.
There are now also several other carrier testing companies on the market that screen what inherited diseases you carry. Speak with your OBGYN, but also do your own research. Not every test covers SMA in their panel. And please note, SMA is NOT part of the Harmony prenatal test, which determines risk of chromosomal abnormalities, such as Down syndrome, specific to that pregnancy. SMA is also not something that can be determined via ultrasound or in office visits.
If you know you are at higher risk already because of family history, many different labs offer a single Spinal Muscular Atrophy carrier test that can be ordered by your OBGYN. This is a simple blood test taken at your local lab and shipped to the specific testing sites across the country. Results will be returned to your OBGYN within two weeks. The cost will vary depending on your insurance. Be sure to speak with your insurance beforehand about the out of pocket expense as the cost can be up to $1,000. Contact Quest Diognostics/Athena, LabCorps/Genzyme, or The Molecular Pathology Labratory to learn more.
Want more in-depth information about SMA? Click HERE.