This battle will look at the 3 commonest trisomies in order of their frequency, which helpful is the same as the order of their names alphabetically.
Down's Syndrome = Trisomy 21
Causes of Down's:
- non-disjunction: 94%
- Robertson translocation: 5%
- mosaicism: 1%
Risk of Downs with age of mother:
- 30 yrs: 1/1000
- 35 yrs: 1/350
- 40 yrs: 1/100
- 45 yrs: 1/30
The characteristics of patients with Down's are varible but include:
- microgenia (=small chin)
- macroglossia
- epicanthic folds of eyes
- short neck
- single palmar crease
- flat nasal bridge
- low IQ
- short stature
Associations with Down's include:
- duodenal atresia
- Hirschsprungs disease
- AV septal defects (40%)
- ventricular septal defects (30%)
- atrial septal defects (10%)
- PDA/tetralogy of fallot
- Brushfield spots (=white spots on iris)
Later complications include:
- ALL
- atlantoaxial instability
- hypothyroidism
Edwards Syndrome = Trisomy 18
Characterised by:
- prominent occiput
- microcephaly
- overlapping fingers
- rockerbottom feet
- cardiac defects
Rare to survive beyond infancy
Patau's Syndrome = Trisomy 13
Characterised by:
- CNS, renal and cardiac abnormalities
- low IQ
- polydactyly
- rockerbottom feet
Rare to survive beyond infancy.
To the final battle of the day - hereditary angioedema
