What is SMA Disease (Spinal Muscular Atrophy)?
SMA Disease (Spinal Muscular Atrophy) is an inherited muscle disease that affects the anterior horn nerve motor cells in the spinal cord and limits their mobility.
With SMA disease, which is mostly seen in infants and children, children’s muscles weaken and shrink. Accordingly, they may have difficulty in controlling their head movements, sitting and even walking without assistance, and as the disease worsens, they may have problems swallowing and breathing.
Of the four types, some types of SMA occur earlier and are more severe than others. Although there is no definitive cure for SMA, some symptoms can be improved and a longer life can be achieved. Therefore, any type of SMA needs ongoing treatment by a medical care team.
Its incidence is 1/10,000 worldwide and 1/6,000 in Turkey. Every child or adult with SMA has a different experience. Although movement is limited in the disease, vision and hearing are not affected by the disease. Intelligence is normal or above normal.
What is SMA (Spinal Muscular Atrophy) Screening?
Since SMA (Spinal Muscular Atrophy) is a genetically inherited disease, it is possible for parents to learn whether their children carry this mutation with a simple blood test in order to prevent their children from being born with the risk of this disease.
After examining the mutations seen in more than 95%, the results are shared with genetic counseling. Other rare mutations can be examined with additional tests when necessary.
After the result is determined, if the person is a carrier, they are directed to the relevant specialists and a roadmap is drawn up against the risks related to this disease. Thus, it is possible to take precautionary measures by informing the families that the baby may be born sick.
Who is SMA (Spinal Muscular Atrophy) Screening Test Performed?
SMA Carrier screening will be applied to people who apply for a medical report before marriage and people who are still married.
What is Looked For in The SMA (Spinal Muscular Atrophy) Test?
The SMA test, which is related to SMA disorder, which is common in the world, is applied by taking DNA samples from the amniotic fluid taken from the fetus during pregnancy. As a result of this test, if there is a certain mutation in the genes, it will be determined by the test.
If You Conceive Without Having The SMA Screening Test!
- You can find out within 10 days whether your baby has SMA by taking CVS (Chorionic Villus Material) from the mother’s womb at 12 weeks of pregnancy.
- At the 16th week of pregnancy, you can find out within 10 days whether your baby has SMA by taking AS (Amniotic Synthesis) Fluid in the womb.
- You can find out within 10 days whether your baby has SMA by taking cordocentesis (cord blood) from the mother’s womb at the 20th week of your pregnancy.
What Causes SMA Disease ?
SMA is a genetic condition caused by a change in a gene called ‘survival motor neuron 1’ (SMN1). Everyone has two copies of the SMN1 gene, inherited from each parent. People with SMA have gene changes in both copies of the SMN1 gene. This condition is called ‘autosomal recessive inheritance’. The parents of a person with SMA each carry one copy of the altered SMN1 gene and are known as ‘carriers’.
These people do not have signs and symptoms of SMA disease. If both parents are carriers, there is a 25 percent (one in four) chance that the child will have SMA. One out of every 40 people is a carrier of the gene variation that causes SMA.
What are The Symptoms of SMA Disease (Spinal Muscular Atrophy)?
The symptoms seen in SMA differ according to the type of the disease and the time of its onset.
Symptoms Seen in SMA Type 1:
- Weakness, laxity (hypotonia) in the arms and legs
- Weak, powerless crying
- Difficulty in moving, swallowing and breathing
- Difficulty in holding the head or sitting unassisted.
Symptoms that occur in SMA Type 2 tend to be milder than in Type 1.
Symptoms Seen in SMA Type 2:
- Difficulty standing up on their own
- Weakness in arms and legs
- Tremors in hands and fingers
- Scoliosis (S or C-shaped curvature of the spine)
- Weakness in respiratory muscles
- It can be counted as having difficulty in coughing.
SMA Type 3 patients: Can stand up and walk on their own. However, patients may lose this ability over time.
Additional Symptoms in Patients:
- Difficulty standing up from sitting position
- Balance problems
- Difficulty climbing stairs and running
- It can be listed as scoliosis.
Symptoms Seen in SMA Type 4:
- Weakness in hands and feet
- Difficulty walking
- It is in the form of trembling and twitching in the muscles.
What are The Types of SMA Disease (Spinal Muscular Atrophy)?
TYPE I SMA (Werdnig-Hoffmann)
It is the most severely progressive disease of the spinal muscular atrophy type. The disease begins in the prenatal period and in the first 6 months of life.
Mothers of prenatal babies with Type I SMA may notice decreased baby movements in the last stages of their pregnancy, and when babies are born, they cannot sit without any support, cannot lift their head, have difficulty in sucking and swallowing, have difficulty coughing due to the respiratory muscles being affected by the disease, and for more than two years due to respiratory tract infections. they cannot live.
Apart from all these, babies with Type I SMA have normal facial reflexes and movements, their gaze is lively and they make eye contact. Since their brain functions are not affected, there is no deterioration in their attention to the environment. Communication skills are strong.
TYPE II SMA (Intermediate Form)
Type II SMA is the type of SMA seen up to 1.5 years of age in children who can crawl but cannot walk in the stage after 6 months. In the period up to the 6th month, the development of babies is normal. Unlike Type I SMA, these patients have head control and can sit unsupported.
Most patients with this type of SMA cannot stand and walk without assistance, cannot move from lying to sitting position without support, and are not resistant to respiratory tract infections.
TYPE III SMA (Kugelberg-Walender)
In patients in this group, the symptoms begin after the 18th month and have a milder course. Patients can walk on their own unaided, but have difficulty in activities such as climbing stairs. Most patients require a wheelchair later in life.
The disease can often be overlooked because the initial symptoms are so mild. Children cannot demonstrate similar physical activities with their peers. Although patients can walk, their muscles are very weak. As the disease progresses, weakness in the leg and hip muscles prevents running, so falls are common and walking becomes difficult.
TYPE IV SMA (Adult Type SMA)
Type-4 SMA occurs in adulthood. The onset and progression of the disease is slow, pauses may also be seen. Type IV adult SMA patients are usually able to walk; A small number of adult SMA patients require a wheelchair.
Twitching, weakness, tremor, scoliosis are seen in the arms and legs. The muscles used in respiratory and swallowing functions are rarely affected in type 4 patients. As a result of muscle wasting and weakness, patients have difficulty in maintaining their daily lives.
How is SMA Disease (Spinal Muscular Atrophy) Diagnosed?
Doctors don’t normally test babies for SMA.
SMA disease is usually not diagnosed early unless the parents are known to be carriers of SMA or the baby has significant muscle weakness, breathing or feeding difficulties soon after birth.
Often, doctors can tell if a child has SMA only if the child misses certain developmental milestones, such as being able to hold their head up or stand unaided.
In most cases, the diagnosis of SMA;
- Progressive muscle weakness,
- Parental concerns
- And as a result of additional tests as a result of increased doctor visits due to respiratory problems.
Diagnosis is usually made after several tests to rule out other diseases that cause similar symptoms.
These tests usually include:
- Nerve conduction tests such as electromyogram (EMG)
- Computed tomography (CT) scan
- Magnetic resonance imaging techniques (MRI)
- Muscle tissue biopsy
To confirm a diagnosis of SMA, the doctor will usually recommend a blood test that looks at the patient’s genes. If the SMN1 gene is missing or defective, it will confirm the diagnosis of SMA. The doctor will also recommend that parents and other members be screened for the disease, even if they show no symptoms
What are The Symptoms that Occur with SMA?
SMA patients may be prone to respiratory tract infections.
It can cause serious problems, especially in patients with pneumonia affecting the lower respiratory tract.
In patients with pneumonia;
- Shortness of breath,
- It causes symptoms such as vomiting.
How is SMA Disease (Spinal Muscular Atrophy) Treated?
‘How is SMA disease treated?’ The question is asked frequently. There is no known definitive treatment for SMA disease. In the treatment stages of children affected by SMA; The focus is on managing symptoms caused by the disease, preventing complications, and improving patients’ quality of life. Your doctor will determine the best options for treating SMA for your child, based on the type of SMA, the severity of the condition, and the child’s age.
Because children with SMA Type 1 are prone to respiratory infections and pneumonia, treatment may focus on preserving lung function. In contrast, care for a child or adult with SMA Type 3 or 4 may focus on physiotherapy to help maintain muscle strength and mobility.
Treatments for people with type 1 SMA may include feeding tubes, ventilators, and other methods of respiratory assistance. Physical therapy can also benefit people with Type 1 SMA. Many patients with this type of spinal muscular atrophy spend most of their lives in the hospital.
Treatments for Type 2 and Type 3 SMA patients may include orthopedic braces, wheelchairs, and physical and occupational therapies.
It is important to know that the brains of patients with spinal muscular atrophy develop normally. Many patients with SMA are highly intelligent and social. Talking to them, playing games, and providing other forms of mental stimulation contribute positively to the emotional and physical lives of these children.
In summary, treatment options to manage the symptoms caused by the disease and prevent complications include:
It aims to improve the quality of life of both the patient and their family, focusing on relief from the symptoms and stress caused by the disease.
In some forms of SMA, it helps improve posture, prevent joint immobility, and slow muscle weakness and atrophy.
It focuses on adjustments that can help patients manage their daily lives to improve their quality of life.