Etiology:

Trisomy 21:

• Non-disjunction (94%)
• Translocation
• Mosaicism

Risk increases with mothers age

Clinical:

1. CVS:

• Ventricular septal defect
• AV communication
• Persistent ductus arteriosus
• Mitral valve prolapse
• Teratology of Fallot:
  • Pulmonary valve stenosis
  • Ventricular septal defect
  • Overriding aorta
  • Right ventricular hypertrophy

2. CNS:

• Delayed motor function
• Early aging
• Mental retardation
• Dementia

3. Eyes:

• Epicanthic folds
• Convergent strabismus
• Nystagmus (involuntary eye movement)
• Refractive errors
• Keratoconus (conical cornea)
• Cataracts
• Ocular hypertelorism

4. Oral:

• High palatal vault
• Insufficient soft palate
• Macroglossia
• Mouth breathing
• Delayed eruption
• Hypodontia
• Microdontia
• Malocclusion

5. Immunity:

• Impaired
• Neutrophil defects
• Thyroid dysfunction
• Increased risk of ALL (Acute lymphocytic leukemia)

6. Musculoskeletal:

• Underdeveloped maxilla and sphenoid
• Prognathic mandible
• Rib and pelvic abnormalities
• Subluxation of patella
• Simian palmar crease

Diagnosis:

In utero:

• Ultrasound
• Amniocentesis
• Chronic villus sampling
• Blood test
• Nuchal translucency test

New born:

• Blood test – chromosomal karyotype

Management:

Regular reviews for; CVS, audiologic, ophthalmologic, dental