Related Subjects: | Dementias
Aetiology
- Non disjunction 94% - related to maternal age
- Mosaics 2% a mix of cells with trisomy 21 and not
- Robertsonian translocation 4% ie inherited
Clinical
- Epicanthic folds, Simian crease, Brushfield spots, Low IQ
- Tracheoesophageal fistula, Leukaemia, Hypothyroid
- Small ears, Hypotonia, Flat occiput, oval face
- Cardiac defects - Septum primum ASD and endocardial cushion defect, PDA, Fallot's tetralogy
- Gut - Duodenal atresia, Hirschsprung's disease
Later
- Leukaemia and solid tumours
- Hypothyroid and coeliac disease
- Epilepsy, Alzheimer's disease
investigations
- Routine ultrasound at 18 weeks gestation: nuchal thickening, atrioventricular septal defects as in this fetus, double bubble sign suggests duodenal atresia which again suggests Down syndrome. Gastrointestinal malformations occur in 6% of Down syndrome patients - most commonly duodenal atresia and Hirschsprung's disease.
Down syndrome