SMA is a rare genetic disease that affects the part of the nervous system that controls voluntary muscle movement.
In SMA, there is a loss of important cells in the spinal cord called motor neurons. Over time, the breakdown of these neurons leads to a gradual decline in muscle size and strength.
SMA is caused by a mutation in a gene called the survival motor neuron 1 (SMN1) gene.
The SMN1 gene is responsible for producing survival motor neuron (SMN) protein, which helps keep motor neurons healthy.
In individuals with SMA, both copies of the SMN1 gene are deleted or damaged
As a result, no SMN protein is produced and over time motor neurons are lost, leading to the symptoms of SMA
Nearly all people have a gene that is nearly identical to SMN1, known as the survival motor neuron 2 (SMN2) gene.
Only 10% of the SMN protein it produces is fully functional.
SMA affects everyone differently and symptoms can vary greatly according to age and disease severity.
Over time, muscles closest to the centre of the body become weaker, such as those around the shoulders, thighs, and hips. These muscles are responsible for actions
Sometimes, breathing and swallowing may also be affected.
It is believed that SMA does not affect the neurons responsible for cognition (the activities of thinking, understanding, learning and remembering). A study has found that children and adolescents with SMA have normal intelligence, with IQs in the standard range.
Every individual with SMA will experience symptoms differently, and there are many aspects to care. A multidisciplinary approach that includes a variety of medical specialists is recommended and aims to extend life and improve overall health and quality of life.
Recent advances, including new treatment options and improved symptom management, have helped change the outlook for many people with SMA. Be sure to ask your healthcare professional if you have any questions about appropriate care options.
For further information about SMA, speak to your
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