Down Syndrome Flashcards
Down syndrome genetic component
extra genetic material on chromosome 21
Trisomy 21
Non familial trisomy 21
95% of kids with down syndrome
sporadic
there are 47 chromosomes with a free extra chromosome 21
unbalanced translocation
occurs between 21 and another acrocentric chrom
acrocentric chrom is usually 14
3/4 of unbalanced translocations are de novo ( not inherited)
occurs at time of conception or inherited
1/4 recieve affected chrom from 1 parent
Mosaicism
1-2% of cases
there is a mix of two cell lines, one normal and one trisomy 21
milder than complete trisomy or translocation 21
children per year
6,000
AMA risk
20, 35, 40
1: 1441
1: 338
1: 84
Average life expectancy
60 years
Comorbidities
hearing loss - 75%
OM- 50-70%
eye disorders- 60%
OSA
Cong heart defects
GI problems
Hip dislocation, thyroid disease, hematologic dysfunction, neurologic dysfunction
First trimester screening
maternal age
nuchal translucency ultrasound
mat serum human chorionic gonadotropin
preg ass plasma protien A
(detection rate of DS is 82-87%)
Second semester
Quad screening, includes maternal age risk
maternal serum hCG
unconjugated sdtriol
AFP (a-fetoprotein)
inhibin levels
(detection rate is 80%)
Success rate of combine first and second semester screenings
95%
Aneuploidy
Presence of an abnormal number of chromosomes instead of the normal 46
ACOG recomends screening for all women before 20 weeks gestation regardless of maternal age
Neonate with no screenings
review family hx
prev pregnancies, miscarriages, children born with DS or developmental delay
Presenting physical s/s
GENERALIZED HYPOTONIA
epicanthial folds,narrow, upward-slanting palpebral fisures
brushfield spots (yellow or white spots on the anterior surface of the eye)
small, brachycephalic (flat) head, small mouth
dysplastic ears, abnormally shaped auricles
single palmar crease, short 5th finger, may be bent or curved
Most striking s/s in PCP
intelectual disability
developmental delays
hearing loss
hypotonia as an infant
Diagnosis
FISH
Flourescence in situ hybridization
identifies extra copy of chrom 21
Diagnosis
Karyoptype
can identify translocation
diagnostics
CBC
looking for luekemoid reaction or polycythemia
transient myeloproferative disorder ( ass with pancytopenia, hepatosplenomegaly, circulating immature WBCs) incidence is 10% in DS kids
newborn screen including cong hypothyroid incl TSH
Treatments
Manage comorbid conditions, no real treatment
Growth charts
No longer using DS charts, follow standard charts
increased risk of obesity and BMI >85%
development should follow non DS peers
Safety
keep cervical neck stabilized
sleep
increased risk for OSA
sleep study if tired or behavioral problems
Vaccine recomendations
all recomended plus flu, RSV due to increased risk
If >2 years with chronic pulm or cardio disease then PPSV 23 is recomended also
ears
freq otitis media
