8: Down Syndrome Flashcards
What 5 heart conditions are common with down syndrome?
- ASD (most common)
- VSD
- Tetralogy of Fallot
- PDA
- MVP (in adolescence)
What are the 3 most common physical characteristics of down syndrome?
- Generalized hypotonia
- Epicanthal folds
- Transverse palmar creases
T/F Newborns weigh less, are typically shorter, and have smaller occipital frontal circumference as compared to normal infants.
True
T/F Etiologies of down syndrome include frequency of intercourse.
True. Others are:
- A genetic predisposition to nondisjunction.
- Autoimmune action.
- Hormonal alterations in aging women.
- Viral disease.
- Environmental factors.
T/F In males there is an increase in urogenital conditions, including micropenis and hypospadias.
True
Hypotonia includes laxity in ligament structure, which interferes with _____ development.
Gross motor
In nondisjunction, a _____ is produced with an extra copy of chromosome 21 (24 chromosomes total).
Gamete
This is made by the growing fetus and found in amniotic fluid, fetal blood, and maternal blood.
Alpha fetoprotein (AfP)
Down Syndrome is caused by a random event during the formation of _____.
Sex cells
Down syndrome screening is usually offered to women over age _____.
35
Is nondisjunction or translocation responsible for the majority of down syndrome?
Nondisjunction (95%)
Early signs include head tilt, torticollis, or deterioration in gait.
Atlantoaxial instability
T/F The level of disability in down syndrome can vary.
True. Varies d/t extent of extra copy, genetic history, and pure chance.
T/F Increased maternal age is a risk factor for down syndrome.
True
How is down syndrome screened in the 1st trimester?
U/S nuchal translucency + blood test (PAPP-A and HCG).
Combination detects 82-87%.
What is the life expectancy?
60
T/F There are more than 50 diagnostic physical characteristics of down syndrome.
False. There are more than 50, but they are not diagnostic.
How is down syndrome detected in the 2nd trimester (2)?
- Multiple marker screening at 15-20 weeks (AFP + Estriol + HCG)
- Quad screen at 15-20 weeks (AFP + Estriol + HCG + Inhibin A)
The child has the usual 2 copies of chromosome 21, but also has additional material from 21 attached to another chromosome.
Translocation
There is an increased risk of what cancer?
Leukemia (10-20x)
Name the MSK and motor ability defects (7).
- Flat feet
- Scoliosis
- Dislocated hips
- Atlantoaxial subluxation
- Joint and muscle pain
- Muscle fatigue
- Wide-based gait
When does the tendency to be overweight start?
2 yo, though at every age they are above 85%.
Is nondisjunction more common in the maternal or paternal gamete?
88% from maternal. 8% from paternal. Chromosomes can fail to pair or fail to exchange genetic material, or both. Increases with maternal age.