Marfan's syndrome (comparison with homocystinuria)
Last reviewed 01/2018
- inheritance:
- Marfan's - autosomal dominant
- homocystinuria - autosomal recessive
- lens dislocation:
- Marfan's - upward lens dislocation
- homocystinuria - downward lens dislocation
- aortic incompetence:
- Marfan's - aortic incompetence may occur
- homocystinuria - heart rarely affected
- intellectual development:
- Marfan's - normal
- homocystinuria - mental retardation
- other principle features:
- Marfan's - flat feet, herniae, scoliosis; there is a 50% reduction in life expectancy
- homocystinuria - osteoporosis, recurrent thromboembolism; characteristic laboratory features - plasma methionine and homocystine levels are elevated, homocystine is excreted in the urine, plasma cystine levels are reduced, positive urine cyanide-nitroprusside test; response to treatment with pyridoxine