Marfanoid hypermobility


An inherited connective tissue disorder with certain characteristics of Marfan and Ehlers-Danlos syndromes. Ehlers-Danlos syndrome is characterized by hyperextensible skin and loose joints and Marfan syndrome is characterized by symptoms such as tall, slender build, ear anomalies and hand contractures.


* Tall stature * Slender build * Arachnodactyly * Fibrous tendon contractures in hand * Sparse subcutaneous fat


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.


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.


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.