Newborn Genetic Screening for Spinal Muscular Atrophy
Spinal muscular atrophy (SMA) is a rare genetic condition that causes muscle weakness. SMA is caused by a mistake in a specific gene. People with the faulty gene are not able to produce the proteins needed for nerve cells to work. They may have difficulty with daily tasks like walking, breathing, and eating.1,2
SMA can get worse over time. And there is currently no cure for it. If SMA is diagnosed early, the disease can be monitored and managed. Newborn genetic screening allows SMA to be diagnosed early so that available treatment can be more effective.1,2
What is newborn genetic screening?
Genetic testing looks for changes in a person’s genes to help diagnose a specific disease. In newborn genetic screening, a small amount of blood is taken from a newborn baby’s heel. The blood is checked for changes in specific genes that cause disease.
For SMA, the blood is checked for a fault in a gene called SMN1. There are different types of SMA. The most common is SMA type 1. And the standard genetic test for diagnosing SMA can detect 95 percent of cases of this type.1-3
Why is genetic screening important for SMA?
SMA type 1 affects mainly children. Symptoms of SMA type 1 can appear in the first months of a baby’s life. If it is not treated early enough, it can worsen quickly. There is a treatment approved by the US Food and Drug Administration (FDA) for SMA type 1 called nusinersen (Spinraza®). If it is used early to treat SMA, it may prevent damage to nerve cells.1,2
Newborn genetic screening can help to diagnose SMA in babies soon after they are born. This can help doctors understand if a baby will benefit from early treatment. And early treatment may be able to slow the progress of the disease.1,2
Where can I get my baby tested for SMA?
Since 2018, newborn genetic screening for SMA has been included in the Recommended Uniform Screening Panel (RUSP). The US Secretary of Health and Human Services recommends that each US state include the disorders listed in the RUSP in its newborn screening program.2
As of July 2022, 47 US states routinely screen newborns for SMA. The only states that do not are Hawaii, Nevada, and South Carolina. This means that 97 percent of babies born every year in the United States are screened for SMA. Most health insurers cover the cost of newborn genetic screening. Check with your insurer if they provide coverage for newborn screening or genetic testing.1,4,5
What happens if the test says my baby has SMA?
Newborn genetic screening can diagnose if a baby has SMA. But it cannot tell which type of SMA the baby has. If the newborn genetic test has diagnosed SMA in your baby, they will need further testing. Your doctor will refer you to a specialist, such as a pediatric neurologist. The specialist should have more experience taking care of babies with SMA. The specialist will conduct additional tests and start any treatment.4
Getting genetic counseling and testing yourself
Genetic counseling may be offered to you if your baby is diagnosed with SMA. But you can also have genetic counseling and testing before you get pregnant.1,3
Genetic testing can detect if you or your partner could be an SMA carrier. A carrier of SMA carries one copy of the faulty gene that causes SMA, but does not have the condition themselves. Understanding if you are an SMA carrier can help with family planning. A genetic counselor can support families to understand:1,3
- What being a carrier means
- The results of any genetic tests
- The chances your other children or family members will have SMA
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