Marfan syndrome
Incidence
1 in 10,000 live births. The disorder exhibits autosomal dominant inheritance with 15 percent of patients representing new mutations. Affected individuals have a 50% risk for transmission to offspring.
Clinical Characteristics
A pattern of manifestations including ectopia lentis and dilatation or aneurysm of the aorta in individuals with tall and thin body build (\"Marfanoid habitus\"), long, lax fingers (\"arachnodactyly\"), and limbs (\"dolichostenomelia\"), other findings of connective tissue weakness such as striae, pectus excavatum, scoliosis, hernias, and flat feet; major manifestations in two organ systems plus minor findings are required for diagnosis. Several conditions may exhibit the elongated body proportions and tall stature of a Marfanoid habitus, but the presence of these proportions plus ectopia lentis (slipped lens) and aortic aneurysm (dilation of the large artery or aorta near the heart) is strongly suggestive of Marfan syndrome. Cystic medial necrosis of the aorta by itself is suggestive but not diagnostic of Marfan syndrome. The cardiac symptoms of adolescents and adults with Marfan syndrome include palpitations, shortness of breath, and light-headedness associated with mitral valve prolapse and chest pain related to pneumothorax (ruptured lung) or aortic dissection (tearing of the aortic artery). Besides the cardinal eye, heart, and skeletal manifestations, children with Marfan syndrome can include a high palate with dental crowding; severe spinal curvature with restrictive lung disease and heart failure; unusual lens shape (microspherophlakia) with later predisposition to cataracts; retinal problems and detachment; increased bruisability but normal healing of skin; and stretching of the spinal cord lining (dura) with neck or abdominal pain.
Precipitants
none
Provocation Tests
none
Diagnostic Procedures
Generally it is a clinical diagnosis. Mutations in the fibrillin gene on chromosome 15 cause Marfan syndrome, but DNA diagnosis is not routinely available.