Spinal Muscular Atrophy

2. Spinal Muscular Atrophy
• Autosomal recessive disease affecting the
(lower) motor neurons in the spinal cord
and brainstem, resulting in progressive
motor weakness and atrophy
• Broad phenotype spectrum ranging in age
of onset (birth to adulthood), severity, and
clinical course – Types of SMA are primarily
distinguished by the severity of muscle
weakness and age of symptom onset –
Types 1 & 2 are most severe

3. Type 0. This is the rarest and most severe form of SMA and develops
while you’re still pregnant. Babies with this type of SMA move less in
the womb and are born with joint problems, weak muscle tone, and
weak muscles for breathing. They often do not survive due
to breathing problems.
Type 1. This is also a severe type of SMA. A child may not be able
to support their head or sit without help. They may have floppy arms
and legs and problems swallowing.
The biggest concern is weakness in the muscles that control breathing.
Most children with type 1 SMA don't live past age 2 because of
breathing problems.

4. Type 2. This affects children 6-18 months old. The symptoms range from moderate to
severe and usually involve the legs more than the arms. The child may be able to sit
and walk or stand with help. Type 2 is also called chronic infantile SMA.
Type 3. Symptoms for this type start when children are 2-17 years old. It's the mildest
form of the disease. The child will most likely be able to stand or walk without help
but may have problems running, climbing stairs, or getting up from a chair. Later in
life, they may need a wheelchair to get around.
Type 3 is also called Kugelberg-Welander disease or juvenile SMA.
Type 4. This form of SMA starts when you're an adult. You may have symptoms such as
muscle weakness, twitching, or breathing problems. Usually, only your upper arms and
legs are affected.
You'll have the symptoms throughout your life, but you can keep moving and even get
better with exercises that you'll practice with the help of a physical therapist.
It's important to remember that there's a lot of variation in the way this type of SMA
affects people. Many people, for instance, are able to keep working for many years..

5. SMA is a disease that's passed down
through families. If the child has SMA,
it's because they have two copies of a
broken gene, one from each parent.
When this happens, their body won't be
able to make a specific kind of protein.
Without it, the cells that control
muscles die.
If the child gets a faulty gene from just
one of the parents, they won't get SMA
but will be a carrier of the disease,they
could pass the broken gene to their own
progeny.
Spinal Muscular Atrophy Causes

6. Spinal Muscular Atrophy Diagnosis
Muscle tissue biopsy
MRI
Blood test
Nerve tests, such as an electromyogram (EMG)
CT SCANS

7. PRESENTED BY – PRANAV KOHLI
GROUP 10