Types of spinal muscular atrophy

Spinal muscular atrophy is a dangerous disease, severely affecting the reflex function of the human body. Depending on the classification, patients with spinal muscular atrophy all notice that the body is weak and difficult to move to different degrees.

The spinal cord is an important part of the body, located inside the spinal muscles, is a segment containing nerves connecting from the brain to the whole body, has a role in transmitting information signals between the brain and the body. rest of the body. The spinal cord plays an important role in the body's reflex function.
Therefore, spinal muscular atrophy or spinal muscular atrophy (SMA) is a dangerous disease that severely affects the reflex function of the human body. In general, patients with spinal muscular atrophy all notice that the body is weak and difficult to move to varying degrees. However, spinal muscular atrophy does not affect the patient's intelligence and learning and receptivity.
Potential complications that can occur from spinal muscular atrophy include:
Fractures, hip dislocations and scoliosis or curvature of the spine; Malnutrition , dehydration caused by problems with eating and swallowing, leading to the need for a feeding tube; Pneumonia and respiratory infections; Weak lungs and breathing problems may require breathing assistance.

Spinal muscular atrophy, especially cervical spinal muscular atrophy, greatly affects the life and health of patients. There are many types of spinal muscular atrophy, which occur at different ages and vary in severity. Spinal muscular atrophy type 0 is rare and usually fatal before the child is born or soon after. Here are 4 other types of spinal muscular atrophy:
2.1. Spinal muscular atrophy type 1 Type 1 spinal muscular atrophy, also known as Werdnig-Hoffmann disease, is the most common type of spinal muscular atrophy, often with onset in infancy. Symptoms of spinal muscular atrophy type 1 can appear between the time a child is born and the first 6 months of life. Most children with spinal muscular atrophy will show signs of the disease by the time they are 3 months old. Most infants with cervical spinal muscular atrophy type 1 die within the first few years of life, with difficulty surviving beyond 2 years of age.
Babies with spinal muscular atrophy type 1 show signs of not being able to raise their head or sit without assistance, very weak arms and legs, problems with movement, difficulty eating and swallowing . Spinal muscular atrophy type 1 can progress very quickly, with weak muscles leading to respiratory infections and severe breathing difficulties that can lead to death.
2.2. Spinal muscular atrophy type 2 This type of spinal muscular atrophy is also known as intermediate spinal muscular atrophy or Dubowitz disease. Spinal muscular atrophy type 2 usually affects children starting at about 3 to 15 months of age, before they can stand or walk on their own.
Spinal muscular atrophy type 2 affects the child's legs more than the arms. Children with spinal muscular atrophy type 2 are usually able to sit without support, but cannot walk.
In adolescents and older, as the disease progresses, the patient needs support to be able to move. A child with spinal muscular atrophy type 2 is most likely to have breathing problems, especially while sleeping. The more severe the symptoms of spinal muscular atrophy, the shorter the survival time.
2.3. Spinal muscular atrophy type 3 Spinal muscular atrophy type 3 usually begins to show symptoms between 18 months of age and adolescence, so it is also called juvenile spinal muscular atrophy. This type of disease is also known as Kugelberg-Welander syndrome. For children, this is the mildest form of spinal muscular atrophy.
Most children with spinal muscular atrophy type 3 can walk and stand on their own. However, they will often fall and have difficulty getting up from a chair or climbing stairs. Spinal muscular atrophy type 3 makes them weak, most commonly in the arms and legs. Finally, patients with spinal muscular atrophy type 3 may need a wheelchair to get around.
2.4. Spinal muscular atrophy type 4 Type 4 spinal muscular atrophy, also known as adult spinal muscular atrophy, is very rare. Symptoms do not begin until the person is in their 20s or 30s. The person also has weakness in the arms and legs and some breathing problems, but the symptoms are mild and progress slowly.
Even many people with spinal muscular atrophy type 4 don't know they have it until years after symptoms start to become apparent. Usually, spinal muscular atrophy type 4 does not usually affect the life expectancy of the patient.

People with muscular dystrophy will often be partially missing the SMN1 gene or have a mutated gene. A healthy SMN1 gene makes the SMN protein, a protein needed by motor neurons to help the body function properly.
People with spinal muscular atrophy do not make enough SMN protein, so motor neurons shrink and die. As a result, the brain cannot control body movements, especially those in the head, neck, arms and legs.
In addition, humans also have the SMN2 gene, a person can have up to 8 copies of the SMN2 gene to make small amounts of the SMN protein, limiting the severity of the problem with the SMN1 gene.

It is very difficult for patients with spinal muscular atrophy to recover completely. Treatment depends on the type of spinal muscular atrophy and the specific symptoms in each patient. Many people with spinal muscular atrophy improve with participation in physical therapy programs, mobility, and the use of assistive devices such as braces, crutches, walkers, and wheelchairs.
The following are some of the therapies used to manage spinal muscular atrophy:
Disease-modifying therapies: Use drugs that stimulate SMN protein production such as Nusinersen for children aged 2 to 12 or Risdaplam for children. adults and children over 2 months old. Gene replacement therapy: Children under two years of age can receive intravenous (IV) onasemnogene abeparvovec-xioi to replace a missing or faulty SMN1 gene with an active one. Besides, spinal muscular atrophy is an inherited disease, so if a spouse carries a mutated gene that causes the disease, they should consult experts and doctors to perform screening therapies before pregnancy to reduce the risk. Inheritance of spinal muscular atrophy to offspring. The diagnosis, transfer, identification of embryos that do not have mutated genes during in vitro fertilization (IVF) will ensure that the fetus has two healthy SMN1 genes and does not have spinal muscular atrophy at birth. .

References: my.clevelandclinic.org, webmd.com, nhs.uk