Diseases
Spinal Muscular Atrophy
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Overview
Spinal muscular atrophy (SMA) is a genetic condition that makes the muscles weaker and causes problems with movement. It's a serious condition that gets worse over time, but there are treatments to help manage the symptoms.
Symptoms
- Floppy or weak arms and legs
- movement problems – such as difficulty sitting up, crawling or walking
- twitching or shaking muscles (tremors)
- bone and joint problems – such as an unusually curved spine (scoliosis)
- swallowing problems
Causes
- People with SMA are either missing part of the SMN1 gene or have a changed (mutated) gene. A healthy SMN1 gene produces SMN protein. Motor neurons need this protein to survive and function properly.
- People with SMA don’t make enough SMN protein, and so the motor neurons shrink and die. As a result, the brain can’t control voluntary movements, especially motion in the head, neck, arms and legs.
Risk factors
- Spinal muscle atrophy is a genetic disorder. Most forms of SMA are caused by mutations of the survival motor neuron 1 gene (SMN1) on the fifth chromosome, resulting in insufficient
Diagnosis
- Genetic testing: a blood test that enables technologists to look for mutations of SMN gene
- Electromyography (EMG): a test that shows how muscles are receiving signals from the nerve
- Muscle biopsy: a small piece of muscle removed for examination under the microscope.
Medicines used
Frequently asked questions
What is Spinal Muscular Atrophy?
Spinal muscular atrophy (SMA) is a genetic condition that makes the muscles weaker and causes problems with movement. It's a serious condition that gets worse over time, but there are treatments to help manage the symptoms.
What are the symptoms of Spinal Muscular Atrophy?
Floppy or weak arms and legs, movement problems – such as difficulty sitting up, crawling or walking, twitching or shaking muscles (tremors), bone and joint problems – such as an unusually curved spine (scoliosis), swallowing problems
What causes Spinal Muscular Atrophy?
People with SMA are either missing part of the SMN1 gene or have a changed (mutated) gene. A healthy SMN1 gene produces SMN protein. Motor neurons need this protein to survive and function properly.; People with SMA don’t make enough SMN protein, and so the motor neurons shrink and die. As a result, the brain can’t control voluntary movements, especially motion in the head, neck, arms and legs.
Which medicines are used for Spinal Muscular Atrophy?
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