Genetics

Question 1

Down syndrome

Answer 1

non disjunction - increased risk with AMA
translocation
mosaicism

brachycephalic 
increased nuchal skin 
open mouth - protuberant tongue 
epicanthic folds and up slanting palpebral features 
HYPOTONIC 
duodenal and jejunal atresia 
hirschprung's 
sublaxation atlas and axis 
increased risk leukaemia 
hypothyroidism 
increased risk DM - tend overweight 
congenital heart defects 

1. maternal serum screening
2. ultrasound: nuchal translucency
3. chorionic villus sampling or amniocentesis
4. non invasive prenatal screening = foetal DNA in maternal circulation

Question 2

FAS

Answer 2

Due to foetal exposure to alcohol during pregnancy 
growth retardation 
typical facial features 
- flat nasal bridge 
- small eyes - microphtalmia 
- thin vermillion border 
- inner epicanthic folds 
- smooth philtrum 
- small mid face 
poor fine motor skills 
neurodevelopment/ cognitive effects - delayed milestones, poor concentration, hyperactivity 
congenital defects: cardiac, skeletal, renal, ocular, deafness, neural tube defects 

complications related to cognitive defects and congenital defects

treatment

• monitor growth and development
• surgery
• neurodevelopmental interventions
• assisted schooling
• genetic counselling

prevention
primary - eliminate alcohol from diet of women reproductive age
secondary - sonar screening
tertiary - screening for cardiac and renal defects, neurodevelopment delay, hearing test