Marfan Syndrome type 2
Overview
A very rare syndrome characterized by some of the skeletal and heart blood vessel abnormalities seen in Marfan syndrome but there are no eye abnormalities. The genetic cause of the two types is different.
Symptoms
* Tall stature * Hollow chest * Pigeon chest * Long arms * Scoliosis
Causes
Marfan syndrome is inherited as an autosomal dominant trait of chromosome 15. It's caused by mutations in gene fibrillin-1, producing changes in elastic tissues, especially of the aorta, eye, and skin. Mutations of fibrillin-1 also cause overgrowth of long bones. In 85% of patients with this disease, the family history confirms Marfan syndrome in one parent as well. In the remaining 15%, a negative family history suggests a fresh mutation, possibly from advanced paternal age.
Diagnosis
Because no specific test confirms Marfan syndrome, diagnosis is based on typical clinical features (particularly skeletal deformities and ectopia lentis) and a history of the disease in close relatives. Useful supplementary procedures, though not definitive for diagnosis, include X-rays for skeletal abnormalities and an echocardiogram to detect aortic root dilation.
Treatment
Attempts to stop the degenerative process have met with little success. Therefore, treatment of Marfan syndrome is basically aimed at relieving symptoms — for example, surgical repair of aneurysms and ocular deformities. In young patients with early dilation of the aorta, prompt treatment with beta-adrenergic blockers may decrease ventricular ejection and protect the aorta; extreme dilation requires surgical replacement of the aorta and the aortic valve. Steroids and sex hormones have been successful (especially in girls) in inducing precocious puberty and early epiphyseal closure to prevent abnormal adult height. Genetic counseling is important, particularly because pregnancy and resultant increased cardiovascular workload can produce aortic rupture.