Spinal Muscular Atrophy – causes symptoms diagnosis treatment

Spinal Muscular Atrophy is a group of diseases that is an autosomal recessive genetic disease that causes muscle weakness due to loss of specific nerve cells called motor parts of neurons which provide muscular movement.

Introduction

Spinal muscular atrophy belongs to an infrequent group of genetic diseases. In this disease loss of motor neurons occurs. However, the accurate reason for this loss is currently not known.

Guido Werdnig was the first to explain this disease in the 1980s. He was a physician at the University of Vienna. He explains this disease in his lecture on the topic “On the Case of Muscular Dystrophy with Positive Spinal Cord Findings”. After his explanation John Hoffmann also explains the atrophy and talks about the reason of death during childhood due to atrophy.

This group of diseases is an inherited disorder which spreads with the removal of the specific type of cells present in nerves called the motor part of neurons which perform function in movement of muscles.

People with this disease cannot control the movement of their muscles because of the loss of the motor neurons, these cells lose from the spinal cord and from the stem cells of the brain. This disease is actually a severe weakness of the muscle and at the peak of disease this wastage of muscle also occurs. People with this disease find difficulty in sitting, standing, walking, running etc. In some cases, affected people also find difficulty in breathing and swallowing of food.

This disease is caused by the removal of death or the removal of the special cells present in nerves called the motor part of neurons from the spinal cord and the stem cells which are present in the brain.

These cells perform functions in receiving nerve impulse from the brain to spinal cord and also that these impulses transfer to the muscles with the help of the peripheral nervous system. Due to this function these cells are the most important part of the nervous system and perform a major role in the movement of muscle. That’s why the loss or removal of these cells causes the weakness of muscles, blockage of the movement of muscles and the wastage of muscles especially in those muscles who are present near the area of the trunk commonly called as proximal muscles for example muscles of hips, shoulder and muscles present at the back. These muscles are specific in function of crawling, walking, sitting and also controls the movement of the head.

Types

Type 1

It is the first type of SMA. The type 1 SMA starts before the birth.it is due to the parent or mothers less moving the fetus in the abdomen. This type of disease occurs when mutation occurs only at the SMN1 gene which is located on chromosome number 5.

This will show symptoms like weakness in muscle, blockage of muscular movement, problem facing during standing, walking etc. this type of disease also called the warding and Hoffmann disease. Children with this type of disease face severe problems in the respiratory system. Due to the severity of this problem of breathing children cannot survive during their childhood and this respiratory disorder leads to death.

Type 2

It is also called the infantile SMA. The type B SMA Affect after the birth. Birth takes place normally but after a few months of birth the muscle tone decreases. That situation is called hypotonia.it affects mostly the muscle of the upper body like the shoulders and arms.it also affects the muscle of the lower body as well like hips so due this the affected can’t sit down normally. This type of disease can also be called the Dubowitz disease.

This disease appears during the first 12 months of childhood. In this period this type of disease shows the specific functions for example weakness of muscle. Children with this disease are not able to walk or stand due the blockage or wastage of muscles. They also have respiratory disorders which means they cannot breathe properly which can lead them to death. That’s why they have short life periods. Their life period is only 20 or 30 years long.

Type 3

This type of spinal muscular atrophy is not fatal or life threatening. People with this type of disease feel weak later in their adulthood. People who are affected with this disease can walk and stand independently. But as the passage of time, they feel weakness in muscles and find difficulty in the running and climbing stairs some people use wheelchairs at old ages. People who are suffering from this disease can live a normal life. This type of disease is also called the Kugel burg we lander disease.

Type 4

This type of disease is an infrequent disease which does not occur commonly. It occurs in early childhood. These persons have muscle weakness and some sort of breathing problems. These people can live their normal lives.

Causes

This is the group of inherited disorders that cause the weakness and as well as the regeneration of muscles progressively. When the brain wants to contract the muscle, it sends a message through the help of upper motor neurons.as the messenger between the brain and the spinal cord.

There is also another kind of neuron that takes the message from the spinal cord to the neuromuscular junction. That neuromuscular junction is between the alpha neuron and muscle cells. Spinal muscular entropy affects these alpha motor neurons.it also affects these alpha motor neurons.it also affects the motor unit a motor is the bundle (consist the motor neuron and muscle cells. Stops working in SMA.

Due to this the muscle cannot contract.it should be painful. And dangerous. If the SMA affects the very large NO. Of neuromuscular junctions then it can be caused by fasciculation. The fasciculation is spontaneous and as well as the involuntary contraction of muscle which is too painful.it also affects the muscle of the chest that has importance in the movement of the diaphragm so that the breathing difficulty is done.

SMN 1 and SMN2 gene which are present on chromosome number 5 are the special gene which performs function in the production of the proteins which are important for the motor neurons to receive and transmit the nerve impulse.

If mutation occurs only on the gene SMN1 then it will cause the only spinal muscular atrophy but if mutation occurs on the gene SMN2 it will discover the type and severity of the disease and mutation. About 20 to 60 have genetic problems which will lead them to the type of spinal muscular atrophy disease.

According to research, if the parents have only SMA then their children will get any 0, 12,3,4 type of spinal muscular atrophy which will not appear at an early age but will appear in adulthood.

Symptoms

There are classes of symptoms:

  •   Primary symptoms
  •   Secondary symptoms

Primary symptoms

This disease will show the following primary functions:

People with this disease find difficulty in movements. This disease will show weakness at the specific muscles like shoulders, hips, trunk etc.

This disease will also show weakness in the muscles present at the back of the body.

Secondary symptoms

Secondary symptoms of this disease are as follows:

People will find difficulty in walking and standing at old ages. These people have to use wheelchairs.

People will find difficulty in breathing in exhaling and inhaling of air.

People will also find difficulty in swallowing and feeding.

Diagnosis

Spinal muscular atrophy can be diagnosed by the following methods:

This disease can be diagnosed by the information of family history and by the various medical tests for example by blood test. Blood tests can be used to observe the mutation on the gene present on chromosome 5.

This disease can also be diagnosed by muscle biopsy. By the muscle biopsy distorted muscle tone or the destroyed structure of muscle can be estimated.

This disease can also be estimated by genetic testing in which mutation on the gene SMN1 and SMN2 can be observed which is located on the DNA which contains chromosomes. And this mutation occurs on chromosome number 5.

Treatment

There is no proper cure of spinal muscular entropy. Several drugs have identified those that may be helpful in the treatment of the spinal muscular entropy.

1) Nutrition through the feeding tube that process is called as the supportive.

2) SMA may also be cured in another way by the therapy that process is called as nusinersen.

The following drug can deal with spinal muscular atrophy:

Spinraza

This can be used for the treatment of all types of SMA. These drugs cure this disease by its regular use for the duration of 2 months depending upon the severity and the type of disease. This works slowly with words by the production RNA which will later produce protein.

Gene therapy

Gene therapy was also suggested for the patient by the doctors. Gene therapy suggested for the children under the age of 2 years.

Summary:

Spinal muscular atrophy is an inherited genetic disease which is spread by the removal of the specific type of cells present in nerves called the motor part of neurons which perform function in movement of muscles.

People with this disease cannot control the movement of their muscles because of the loss of the motor neurons, these cells lose from the spinal cord and from the stem cells of the brain. This disease is actually a severe weakness of the muscle and at the peak of disease this wastage of muscle also occurs.

People with this disease find difficulty in sitting, standing, walking, running etc. In some cases, affected people also find difficulty in breathing and swallowing of food. This disease is spread by the removal of death or the removal of the special cells present in nerves called the motor part of neurons from the spinal cord and the stem cells which are present in the brain.

These cells perform functions in receiving nerve impulse from the brain to spinal cord and also that these impulses transfer to the muscles with the help of the peripheral nervous system. Due to this function these cells are the most important part of the nervous system and perform a major role in the movement of muscle.

That’s why the loss or removal of these cells causes the weakness of muscles, blockage of the movement of muscles and the wastage of muscles especially in those muscles who are present near the area of the trunk commonly called as proximal muscles for example muscles of hips, shoulder and muscles present at the back.

These muscles are specific in function of crawling, walking, sitting and also controls the movement of the head. SMN1 and SMN2 genes which are present on chromosome number 5 are the special gene which performs function in the production of the proteins which are important for the motor neurons to receive and transmit the nerve impulse.

If mutation occurs only on the gene SMN1 then it will cause the only spinal muscular atrophy but if mutation occurs on the gene SMN2 it will discover the type and severity of the disease and mutation. About 20 to 60 have genetic problems which will lead them to the type of spinal muscular atrophy disease.

The cells which are affected by this disease are located in the spinal cord beneath the gray matter and these cells are present in the stem cells of the brain. When any mutation occurs on the gene present on chromosome number 5 these cells start loss and will cause weakness and wastage of the muscle.

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