Value of molecular diagnosis in a family with Marfan syndrome and an atypical vascular phenotype.

Marfan syndrome is mainly caused by mutations in the FBN1 gene. Diagnosis is usually based on clinical criteria, but the phenotypic presentation varies widely among affected individuals. Aortic dissection or rupture is the cause of death in over 90% of untreated patients. Early identification of individuals at risk is important given the availability of medical and surgical treatment that can significantly improve life-expectancy. Molecular testing could provide an etiologic diagnosis in patients who present with milder or atypical clinical forms of the disease. Moreover, it could contribute to preventive treatment in carriers, inform genetic counseling and offer reassurance to unaffected individuals. By describing a family with Marfan syndrome in whom the disease presented in an atypical aggressive form, this article highlights the value of tests for detecting FBN1 mutations in selected cases.