About SMA

Did You Know?

1 in 50

carry the defective

SMA gene

SMA (Spinal Muscular Atrophy) is a neuromuscular disease that takes away the ability to move, walk, eat or breathe without assistance. It is the No. 1 genetic killer of small ones.

Do you know how many babies are born with SMA (Spinal Muscular Atrophy) in Malaysia every year?

An estimated

500,000

babies are born in Malaysia each year.

10,000

babies is born with SMA (world statistic).

That means about 50 babies are born with SMA every year.

This is almost 1 in a week.

Isn’t that worrying? That’s why SMA is the most common rare disorder.

Type I: Severe
Type II: Intermediate
Type III: Mild
Type IV

Type I: Severe

Age of onset is <6 months.
This is the most severe form of SMA.
Within the first few months of birth, baby may have severe muscle weakness, poor swallowing reflexes and breathing.
95% will not make it past their second birthday.
Type II: Intermediate
Age of onset is 7–18 months.
Delay in meeting motor milestones, or failing to meet milestone entirely.
Can sit up without help or with assistance, but unable to walk and require a wheelchair.
Life expectancy may be shortened.
Type III: Mild
Age of onset is 18 months onwards.
Children are able to stand and walk initially, but will grow weaker and many need to use a wheelchair.
Chewing & swallowing may be affected later.
Life expectancy is normal.
Type IV
Age of onset is mid-30s onwards.
Late onset, and similar to Type 3, but is less severe.
Life expectancy is normal.

What causes SMA?
A mutation in the survival motor neuron gene 1 (SMN1).
This leads to missing neuron protein critical for nerve function & muscle control.
How is SMA inherited?
If both parents are carriers of SMA, there is a 25% chance that when they have a child, the child will have SMA.
Who’s affected by SMA?
1 in 10,000 babies.
It affects any race or gender.
1 in every 50 persons is a genetic carrier of SMA.
Early symptoms of SMA?
When a child’s growth is delayed & has difficulty in:
Holding head up
Rolling over
Sitting up
Standing
Walking

Testing

Genetic counselling by qualified personnel is advised if there is any family history of the condition or before any genetic testing is done.

Genetic testing is available to confirm the diagnosis of SMA if there is suspicion of the disease based on physical observation. Carrier testing and genetic counselling are offered for adult family members of an affected patient.

If genetic testing yields a negative result but symptoms typical of SMA are observed, further tests such as muscle biopsy and electromyography may be necessary. Prenatal diagnosis and pre-implementation genetic diagnisus are available for couples who are at risk for having an offspring with SMA.

Frequently Asked Questions

1. If no members of my family are affected by SMA, can I still have a child with the condition?
Yes. Due to the way the disease is inherited, it is possible for the defective gene to be present in the family without anyone showing symptoms. Hence, you may not be aware of a family history.
2. Since SMA is a genetic condition, is it possible to have more than one child with the condition?
Yes. When both parents are carriers of the gene change, there is a 25% risk with each pregnancy of having a child with SMA. This risk may be reduced by prenatal diagnosis and pre-implantation genetic diagnosis.
3. If I am a carrier, can I develop SMA?
No. Carriers do not show any symptoms of the condition as they have one functioning copy of the gene, which is sufficient for the production of the required amounts of protein.
4. Would a child with SMA be able to attend school?
Yes. Children with milder forms of SMA are highly encouraged to attend school. The condition does not affect the mental development of patients.
5. Can people with SMA achieve a normal lifepspan?
Some forms of SMA shorten lifespan. The average lifespan of an SMA patient depends of the age of onset of the condition. The later the age of onset, the higher the likelihood of achieving a normal lifespan. Patients are advised to consult their physician to obtain specific information regarding this.
6. What are the major challenges faced by people with SMA?
Weakness of the respiratory muscles is potentially the most serious issue faced by SMA patients. Ventilatory assistance is usually needed to facilitate breathing. Swallowing and chewing muscles may also be affected in some types of SMA. Those facing this difficulty would often require feeding aids.