Spinal muscular atrophy (SMA) is a rare genetic condition that causes muscles to become atrophied and weak. Most types of SMA begin during infancy or early childhood.
SMA can lead to joint deformities, feeding difficulties, and potentially life threatening breathing problems. Children and adults with SMA may have difficulty sitting, standing, walking, or completing other activities without assistance.
There is currently no known cure for SMA. However, new therapies may help improve the outlook for children and adults with SMA. Supportive therapy is also available to help manage symptoms and potential complications.
Take a moment to learn more about treatment options for SMA.
SMA can affect your child’s body in different ways. To manage their varied support needs, it’s essential to get comprehensive care from a multidisciplinary team of healthcare professionals.
Regular checkups will allow your child’s health team to monitor their condition and assess how well their treatment plan is working.
They may recommend changes to your child’s treatment plan if your child develops new or worsened symptoms. They may also recommend changes if new treatments become available.
To treat the underlying causes of SMA, the Food and Drug Administration (FDA) has recently approved three specific therapies:
- nusinersen (Spinraza), which is approved to treat SMA in children and adults
- onasemnogene abeparvovec-xioi (Zolgensma), which is approved to treat SMA in children under 2 years old
- risdiplam (Evrysdi), which is approved to treat SMA in individuals ages 2 months and older
These treatments are relatively new, so experts don’t yet know what the long-term effects of using these treatments may be. So far, studies suggest that they may significantly limit or slow the progression of SMA.
Spinraza
Spinraza is a type of medication that’s designed to boost the production of an important protein, known as sensor motor neuron (SMN) protein. People with SMA don’t produce enough of this protein on their own. The protein helps motor nerves survive.
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If your child’s doctor prescribes Spinraza, they will inject the medication into the fluid surrounding your child’s spinal cord. They will start by giving four doses of the medication over the first couple months of treatment. After that, they will administer one dose every 4 months.
Potential side effects for the medication include:
- increased risk of respiratory infection
- increased risk of bleeding complications
- kidney damage
- constipation
- vomiting
- headache
- back pain
- fever
Although side effects are possible, keep in mind that your child’s healthcare provider will only recommend the medication if they believe the benefits outweigh the risk of side effects.
Zolgensma
Zolgensma is a type of gene therapy, in which a modified virus is used to deliver a functionalSMN1 gene. People with SMA have a defect in this gene that normally codes for SMN protein.
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Zolgensma is a one-time treatment that’s administered through intravenous (IV) infusion.
Potential side effects include:
- vomiting
- abnormally elevated liver enzymes
- serious liver damage
- increased markers of heart muscle damage
If your child’s doctor prescribes Zolgensma, they will need to order tests to monitor your child’s liver enzymes health before, during, and after treatment. They can also provide more information about the benefits and risks of the treatment.
Evrysdi
Evrysdi is the first oral medication approved for the treatment of SMA. It’s composed of a small molecule that works by modifying the amount of SMN protein that’s made from the SMN2 gene.
Like SMN1, the SMN2 gene produces SMN protein. However, it typically does this at lower levels. In fact, the extent to which SMN2 produces functional SMN protein has an impact on the severity of SMA.
Taking Evrysdi promotes more effective production of SMN protein from the SMN2 gene. This, in turn, helps to increase levels of SMN protein available in the nervous system.
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- fever
- diarrhea
- rash
- mouth ulcers
- joint aches and pains
- urinary tract infections
Additional side effects may also occur in infants with SMA who are taking this medication. These include:
- vomiting
- constipation
- upper respiratory tract infections
- pneumonia
Talk with your child’s doctor about using Evrysdi to treat SMA. They can discuss the potential benefits and risks associated with Evrysdi and how it compares to other treatments for SMA.
Experimental treatments
Scientists are studying several other potential treatments for SMA, including:
- branaplam
- reldesemtiv
- SRK-015
The FDA has not yet approved these experimental treatments. However, it’s possible that one or more of these treatments could be available in the future.
If you’re interested in learning more about experimental options, talk with your child’s doctor about clinical trials. Your healthcare team may be able to give you more information about whether your child could participate in a clinical trial, and the potential benefits and risks.
In addition to SMA treatment that affects the SMN protein, your child’s doctor might recommend other treatments to help manage symptoms or potential complications.
Respiratory health
Children with SMA tend to have weak respiratory muscles, which makes it harder to breathe and cough. Many also develop rib deformities, which can worsen breathing difficulties.
If your child has difficulty breathing or coughing, it puts them at increased risk of pneumonia. This is a potentially life threatening lung infection.
To help clear your child’s airways and support their breathing, their health team may prescribe:
- Manual chest physiotherapy. A healthcare provider taps on your child’s chest and uses other techniques to loosen and clear mucus from their airways.
- Oronasal suctioning. A special tube or syringe is inserted into your child’s nose or mouth and used to remove mucus out of their airways.
- Mechanical insufflation/exsufflation. Your child is hooked up to a special machine that simulates a cough to clear mucus from their airways.
- Mechanical ventilation. A breathing mask or tracheostomy tube is used to connect your child to a special machine that helps them breathe.
It’s also important to follow your child’s recommended vaccination schedule to lower their risk of infections, including influenza and pneumonia.
Nutritional and digestive health
SMA can make it hard for children to suck and swallow, which can limit their ability to eat. This can lead to poor growth.
Children and adults with SMA may also experience digestive complications, such as chronic constipation, gastroesophageal reflux, or delayed gastric emptying.
To support your child’s nutritional and digestive health, their healthcare team may recommend:
- changes to their diet
- vitamin or mineral supplements
- enteric feeding, in which a feeding tube is used to deliver fluid and food to their stomach
- medications to treat constipation, gastroesophageal reflux, or other digestive issues
Babies and young children with SMA are at risk of being underweight. On the other hand, older children and adults with SMA are at risk of being overweight due to low physical activity levels.
If your child is overweight, their healthcare team may recommend changes to their diet or physical activity habits.
Bone and joint health
Children and adults with SMA have weak muscles. This can limit their movement and put them at risk of joint complications, such as:
- a type of joint deformity known as contractures
- unusual curvature of the spine, known as scoliosis
- distortion of the rib cage
- hip dislocation
- bone fractures
To help support and stretch their muscles and joints, your child’s healthcare team may prescribe:
- physical therapy exercises
- splints, braces, or other orthoses
- other postural support devices
If your child has severe joint deformities or fractures, they may need surgery.
As your child gets older, they may need a wheelchair or other assistive device to help them get around.
Living with a serious health condition can be stressful for children, as well as their parents and other caregivers.
If you or your child is experiencing anxiety, depression, or other mental health challenges, let your doctor know.
They may refer you to a mental health specialist for counseling or other treatment. They may also encourage you to connect with a support group for people living with SMA.
Though there is currently no cure for SMA, there are treatments available to help slow the development of the disease, relieve symptoms, and manage potential complications.
Your child’s recommended treatment plan will depend on their specific symptoms and support needs. To learn more about the treatments that are available, talk with their healthcare team.
Early treatment is important for promoting the best possible outcomes in people with SMA.