Exam One - Spinal Muscular Atrophy Flashcards
1
Q
SMA stands for?
A
Spinal Muscular Atrophy
2
Q
SMA is…
A
Neurogenic (ant. horn cell) and motor neurons
muscle wasting and weakness
individuals have normal cognition
3
Q
What type of inheritance?
A
autosomal recessive
4
Q
What gene is defective with SMA?
A
SMN1
survival motor neuron
5
Q
What is the punnet pair ratios for two heterozygous parents having a child?
A
25% unaffected
50% carrier
25% affected with SMA
6
Q
Which chromosome is involved in SMA?
A
5th
7
Q
SMA is important because
A
- part of a protein complex
- essential for all nerves and tissues
- necessary for mRNA function
- unknown WHY primary effect is on anterior horn cells
8
Q
What explains variation seen in SMA severity?
A
SMN2
- less stable protein but partially compensates for lack of SMN 1
9
Q
SMA incidence
A
about 1 in 6000-11000 births
leading cause for infant mortality (this is changing)
10
Q
SMA symptoms
A
- noticed at 6 months: hypotonia, difficulty feeding, managing secretions, respiratory distress, and lack of head control.
- severe muscle wasting, movements made in small amplitudes
- EARLY scoliosis, joint contractures, and greatly reduced BMD
- at risk of Atraumatic factures and hip subluxations/dislocation
- unless treated, most die at age three
11
Q
medical interventions
A
- assisted ventilation (bipap most common but also ventilator with trach)
- percussion vest
- cough assist
- suctioning
-pulse oximeter - G tube
12
Q
Spinraza
A
- most popular treatment
- all ages
- CSF injections (4 loading doses over two months, then every four months)
- tells pre messenger RNA to leave codon 7 in for SMN2
13
Q
Zolgensma
A
- for less than 2
- one time intravenous treatment
- uses viral vector treatment to replace encoding for SMN1 protein
14
Q
Evrysdi
A
- All ages
- oral medication daily
15
Q
Screening at Birth
A
- catch early so you can treat early
- 48 states screen at birth (not nevada or hawaii)
