● Down’s syndrome = Trisomy 21

○ Genetic pathophysiology?
■ maternal nondisjunction (failure to separate in meiosis I or II)
■ Robertsonian translocation (RT)
○ Early onset neuro dz? Alzheimer dz (presenilin is on chromosome 21)
○ Classic hematologic malignancy? ALL (TdT positive)
■ “ALL fall Down”
○ Considerations before beginning sports? Cervical XR to screen for atlanto-axial instability
○ Hand findings? Single palmar crease
○ Common cardiac defect? Endocardial cushion defects (endocardial cushion derived from neural crest)
○ Common GI defects?
■ Hirschprung’s
■ duodenal atresia (bilious vomiting, double bubble)
■ pyloric stenosis (first 8 weeks of life, non-bilious vomiting, olive-shaped mass, erythromycin exposure increases risk)
○ Maternal quad screen findings
■ High beta-hcg & inhibin A
■ Low AFP & estriol
■ “HIGH” → hCG & inhibin are high

• This topic was modified 3 years, 7 months ago by DrSingh.
• This topic was modified 3 years, 7 months ago by DrSingh.