Spinal Muscular Atrophy (SMA)

Brief Introduction: 

Spinal Muscular Atrophy is a neuromuscular illness that leads to advanced proximal muscle weakening and paralysis. It is marked by the damage of Alpha-Motor neurons, a kind of nerve cell that presents in the spinal cord and controls muscle movements. Muscles do not receive nerve impulses that cause them to move unless these motor neurons are present. Atrophy is a medical term that means “to shrink.” Due to a lack of usage, some muscles in Spinal muscular atrophy (SMA) grow smaller and weaker.

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Different Types:

Based on onset age and the level of motor function attained, SMA is categorized into 4 different phenotypes.

Type 1:

SMA type 1 is the most frequent and severe. Werdnig-Hoffmann disease, or infantile-onset SMA, is another name for it. Type 1 children have limited mobility, are unable to be seated without assistance, and have difficulty inhalation, eating, and absorbing. Symptoms appear as soon as a baby is born or during the earliest 6 months of life. Many youngsters with type 1 diabetes do not survive beyond the stage of two.

 Type 2:

Spinal Muscular Atrophy type 2 is an intermediate type of SMA. This kind of child may be able to sit without assistance at some time, but they will not be able to walk on their own. Symptoms usually appear between the ages of 6 and 18 months. Youngsters with type 2 might have a normal lifecycle, depending on the severity of their symptoms.

Type 3:

Type 03 is a warmer version of the disease. It’s well known as (Kugelberg-Welander) disease. While most youngsters with type 03 can walk, they have considerable difficulty doing so. Some people may need to use a wheelchair in the future. Symptoms typically begin at the age of 18 months. Youngsters having this type of (S.M.A) have an almost normal life probability.

Type 4:

Type 4 (SMA) is very uncommon. It typically begins in adolescence and results in moderate motor disability.

What  are the signs and symptoms of Spinal muscular atrophy?

The symptoms and signs of (Spinal Muscular Atrophy) SMA vary significantly depending on the kind. Youngsters with the more severe type of SMA (Type 1) often exhibit more severe symptoms during the earliest life of 06 months. Weaker types have milder symptoms that may not become apparent until the kid is eighteen months old.

Symptoms:

Spinal Muscular Atrophy could cause a variety of symptoms, including:

• Muscular wasting and muscle tone loss

• Restricted mobility

• Breathing difficulties

• Swallowing and eating difficulties

• Delay in gross motor abilities

• Uncontrollable tongue movements

• Scoliosis (abnormal curvature of the spine)

Signs:

Spinal muscular atrophy may cause a variety of signs, including:

• Fasciculation

• Muscle atrophy

• Loss of deep reflexes

• Muscular trembling is an example of fast and distinct involuntary muscle movements.

What causes promote this disorder?

This implies that for a kid to have the disease, both parents must have the genetic mutation (most of the time). The “survival of neurons that are motor” gene is impaired in Spinal Muscular Atrophy that is SMN02 and SMN01.

The SMN2 gene is found in multiple copies in all individuals with SMA. On the other hand, the milder the illness, only generates a tiny quantity of functional SMN protein. The chances of being an SMA carrier rise dramatically if someone in the family has SMA. When both parents are carriers, their child has a one-in-four (25%) chance of being born with SMA with each pregnancy.

What are the diagnosis tests of Spinal muscular atrophy?

Some of the symptoms of (Spinal Muscular Atrophy) SMA are similar to those of other neuromuscular diseases, including muscular dystrophy. A physical exam and a medical history will be performed by healthcare practitioner to determine the source of symptoms. To diagnose Spinal Muscular Atrophy, the doctor may perform one or more of the following tests:

• A blood test for enzymes and proteins:

It may detect excessive levels of creatinine kinase. This enzyme is released into the circulation by deteriorating muscles.

• SMN1 gene test: 

This blood test detects abnormalities in the SMN1 gene. A genetic test is 95% efficient in detecting the changed SMN1 gene as a diagnostic tool. SMA is screened for in certain states as part of standard newborn screenings. A genetic test revealed that the SMN1 gene on chromosome 5 had been deleted.

• An Electromyogram (EMG) 

It is a test that analyses the electrical activity of nerves, muscles, and nerves.

• Muscle biopsy:

On rare occasions, a physician may perform a muscle biopsy. A tiny quantity of muscle tissue is removed and sent to a lab for analysis in this operation. A biopsy may reveal atrophy or muscle loss.

What is the Treatment of Spinal Muscular Atrophy?

Considering the genetic appliance underlying (SMA) has run to the improvement of two therapies. The first involves modifying (SMN2) RNA to produce a full-length (SMN) protein, and the subsequent involves delivering the SMN1 gene directly to the cell via a viral vector.

Physical therapy, occupational therapy, and rehabilitation may aid in the enhancement of position. The anticipation of joint immovability, the prevention of muscle faintness and atrophy are also treated by these therapies. Extending and reinforcement activities may assist with spasticity, range of motion, and circulation.