Prenatal Screening for Spinal Muscular Atrophy

A baby's health is one of the most concerning topics and issues for parents and soon-to-be parents. Planning and expecting parents often feel immense concern over how to measure their baby's health. As well as what can be done when babies are born with genetic health conditions. One genetic condition of concern is spinal muscular atrophy (SMA).

Are you wondering what exactly SMA is and how it is genetically passed? Do you know what to expect for SMA detection? Like other genetic health conditions, SMA can be diagnosed and prepared for even before a baby is born because of SMA prenatal genetic testing. You can find everything you need about SMA and genetic testing below.

A brief overview of SMA

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To understand spinal muscular atrophy testing and treatment, you must first know what SMA is. SMA is a grouped hereditary disease that targets and progressively deteriorates motor neurons. Motor neurons are brain stem and spinal cord cells needed to control skeletal muscle activity. Such activities include breathing, walking, talking, and swallowing. These are hindered by losing the motor neurons required for moving muscles in the arms, legs, chest, throat, face, and tongue.

The destruction of motor neurons disrupts signals between the neurons and muscles, causing muscles to weaken and waste. Often, a twitching reaction (fasciculations) occurs. Commonly, SMA develops by copies of the survival motor neuron 1 gene (SMN1) on chromosome 5q being defective. The SMN protein helps maintain the functionality of motor neurons. SMA essentially causes insufficient SMN protein levels, leading to muscle deterioration. Other SMA types (less common) follow the pattern of mutating essential genes on chromosomes. SMA types differ in the individual's onset age but can overlap.

The types of SMA range from:

• Type 1 (before 6 months of age)
• Type 2 (between 6 and 18 months of age)
• Type 3 (after 18 months of age)
• Type 4 (after 21 years of age)
  

The symptoms of SMA depend on the type of SMA a patient has.

Typical symptoms include:

• Weak arms and legs
• Movement problems
• Tremors
• Bone and joint problems
• Problems with swallowing
• Breathing difficulties
  

SMA does not affect intelligence or cause learning disabilities.

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What does the test involve?

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The thought of prenatal testing can be daunting, but genetic tests are essential for early diagnosis, planning, and treatment. SMA prenatal genetic tests require a sample of the baby's DNA. To do this, SMA uses one of two sampling methods: chorionic villus sampling (CVS) and amniocentesis. CVS is performed at 10 and 13 weeks of gestation, and CVS can be achieved by transabdominal or transcervical methods.

Transabdominal CVS involves inserting a thin needle into the pregnant person's abdomen to extract samples from the placenta. Transcervical CVS inserts a thin tube inside the cervix to remove samples from the placenta. Amniocentesis is similar to transabdominal CVS. However, the needle is inserted into the amniotic sac to extract amniotic fluid. All tests use ultrasound imaging to ensure safety and accuracy.

How to find out if you're a carrier

Carriers of SMA can have only one mutated gene and not show any symptoms. SMA is inherited in an autosomal recessive manner. This means the baby must inherit one mutated gene from each biological parent to be affected by SMA. Children have a 25% chance of having SMA or a 50% chance of becoming a carrier when both biological parents carry SMA mutation. Therefore, both biological parents need to be tested. Carrier testing is performed through genetic testing (blood or saliva).

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What are the risk factors?

Prenatal CVS and amniocentesis tests are invasive and pose a small risk of miscarriage. There is approximately a 1% chance of miscarriage for every 100 tests, and the risk decreases with amniocentesis (1 in 200). Additionally, there is a slight possibility of inaccurate results requiring further testing. It is expected to experience cramping or discomfort within a couple hours after the procedure.

Treatment options for SMA

SMA is presently incurable, but treatments are available to help manage symptoms and prevent further complications. Medication is the first treatment source and is relatively new. The FDA released the first approved drug to treat adults and children in December 2016. Gene therapy was approved in May 2019, where functional SMN genes targeting motor neuron improvement are delivered by a safe virus. SMA symptoms are also treated with therapy (physical, occupational, and speech) and rehabilitation. Other treatments require assistive devices, such as braces, speech synthesizers, and maintaining proper nutrition (nutrition and calories designed to increase strength and gain weight).

Stem cell therapy for spinal muscular atrophy

Stem cell therapy may be another promising treatment option for spinal muscular atrophy. Stem cell transplantation has shown improvements in the following:

• Muscle tone and strength
• Motor function and skills
• Speech and swallowing
• Balance and coordination
• Neuropathic pain
• Tremors and fatigue

This therapy uses mesenchymal stem cells (MSCs). These cells have excellent plasticity and help modulate the immune system. MSCs increase neuron survival, promote a productive environment for neuro growth, reduce causes of neuroinflammation, and more.

Bank your stem cells with Anja Health

For parents, it is essential to know if their child will have a genetic disorder as early as possible. Prenatal genetic testing is available for SMA. The testing can help families determine the best treatment options in case there is a determination or suspicion that their baby may be born with SMA. Stem cell therapy offers promising hope to those affected by SMA.

However, there can be issues of not having available stem cells when needing treatment. You can resolve this issue immediately by banking stem cells from cord blood. Contact Anja Health today to get your stem cell banking process started.