Texas Adds New Screening Requirement For Newborns
When it comes to treating spinal muscular atrophy (SMA), time is of the essence. Every day that passes without treatment can lead to a lesser quality of life and, tragically, even death. But a new and simple screening for newborns has the potential to change that.
This week, SMA was added to the list of required medical screenings every baby in Texas receives at birth. Without newborn screening, many children escape the diagnosis until after permanent neuromuscular damage has occurred. Early recognition and treatment can mean the difference between a near normal life or suffering many skeletal deformities and being unable to breathe without a ventilator.
“The hope and thought is that it’s going to change the lives of patients and their families,” said Stephanie Acord, M.D., a pediatric neurologist at Cook Children’s Jane and John Justin Neurosciences Center. “Without treatment, these kids and those who care for them are significantly affected. The earlier you treat SMA, the better.”
Dr. Acord directs the multi-disciplinary Muscular Dystrophy Association (MDA) Clinic at Cook Children’s Jane and John Justin Neurosciences Center where she and Warren Marks, M.D., medical director of movement disorders at the center, specialize in the treatment of SMA. Dr. Acord shared with us what every expectant parent needs to know about the disorder and the new screening.
What is SMA?
Spinal muscular atrophy is a genetic disorder in which the nerves within the brainstem and spinal cord, called alpha motor neurons, break down and lose the ability to send signals from the brain to the muscles. Without those signals, the muscles grow weak from lack of use and affect a baby’s ability to hold up and control their head, sit up, crawl, walk, swallow, speak and breathe. If left untreated, a child will eventually require a feeding tube and respiratory support, such as a ventilator. Untreated SMA is among the leading genetic causes of death of infants and children.
Spinal muscular atrophy can be passed to a child if both parents have a defective survival motor neuron (SMN1) gene. Parents do not have the disease or signs of the disease and do not usually know they carry an abnormal gene. The faulty gene inhibits the production of the protein that fuels these motor neurons and, without it, the nerves die. There is a back-up copy, the SMN2 gene, but it doesn’t work as well as the SMN1 gene.
It is estimated that about 100 children born in Texas each year have the disorder. Many newborns will not show signs of SMA for months. By that point, you’ve lost valuable treatment time and the ability to give a child with SMA a better life. This is why newborn screening is so important.
What are the signs and symptoms of SMA?
There are several types of SMA. Symptoms vary depending on the type, but muscle weakness and loss of muscle control that worsens over time are general indicators. It is important to note that SMA is not a cognitive disorder, but a muscular one.
Type 0 is the rarest and most severe form of the disorder. Babies born with Type 0 SMA have breathing problems very early on and typically do not survive.
Type 1 is the most common form of SMA and also considered severe. Infants will begin showing signs within six months of life. They have poor head control, do not sit independently and have difficulty sucking and swallowing. Even though cognitively they are normal, they are unable to speak due to weakness. Without treatment they will need assistance with breathing, feeding, communicating, sitting and walking.
Type 2 is a more moderate form of the disorder. Symptoms will become evident between six months to 18 months of life. Infants with Type 2 will have difficulty controlling their lower limbs. They may be able to sit independently and crawl but struggle with walking.
Type 3 is a milder form of SMA. Symptoms such as mild muscle weakness, difficulty walking or frequent respiratory illness do not appear until after 18 months of life. Some people may not experience symptoms until early adulthood.
Type 4 is adult onset SMA. It is rare, progresses slowly and typically doesn’t appear until the early 30s. Most people maintain mobility and are able to manage their symptoms without much interruption to their lives.
What treatment is available for SMA?
The Federal Drug Administration (FDA) approved the first treatment for SMA in December 2016.
“It used to be a diagnosis in which there was very little treatment and little hope,” Dr. Acord said. “But the treatment now available for these patients is completely different than it was just five years ago.”
Today, there are three FDA-approved treatments. Two—Spinraza® and Evrysdi®—are drug therapies that help stimulate the production of a more functional SMN2 protein. These two treatments require ongoing administration of medication at various time intervals. The other—Zolgensma®—is a gene-replacement therapy administered once through an IV that delivers a normal functioning copy of the SMN1 gene.
The treatments have varying degrees of success, but all work to improve the strength and function of muscles through healthier neurons. They help to prolong the amount of time a child can live without additional support such as equipment to help them breathe more comfortably, as well as increase their ability to speak with their voice and to eat to some extent by mouth. The most critical part of any of the treatments is to start as soon as possible following diagnosis.
How will my newborn be screened for SMA?
As of June 1, 2021, SMA is one of 55 disorders on Texas’ list of required newborn screenings. It does not require an additional test. It’s simply bundled into the routine screenings already performed on newborns via blood test.
What happens if my newborn is positive for SMA?
If your newborn’s screening is positive for SMA, it is recommended that they be referred to a specialist, either a pediatric neurologist or a pediatric neurogeneticist, within 24 hours. A specialist will most likely conduct additional testing to confirm the diagnosis and develop a treatment plan.
“Parents need to advocate getting their child to a specialist as quickly as possible,” Dr. Acord said about receiving a positive SMA screen.
Pediatric neurologists at Cook Children’s Medical Center are able to conduct many SMA assessments virtually via telemedicine, which is helping parents and children in parts of the state without specialists get access to care from the comfort of their home.
Click here to learn more about the Muscular Dystrophy Association Clinic at Cook Children’s and for contact information for clinic staff.