[Marfan syndrome in childhood and adolescence].

The Marfan syndrome is a systemic connective tissue disorder with autosomal dominant inheritance. A mutation of the fibrillin-1 gene, a glycoprotein which is the main constituent of the extracellular matrix, is the cause of the disease. The cardinal features involve the skeletal, ocular and cardiovascular systems. The expression of the Marfan syndrome varies from the severe neonatal presentation to the classical manifestations of the child and young adult, but also comprises isolated features. In children, phenotypical manifestations are age dependent. For these reasons, the diagnosis of Marfan syndrome might be lately revealed by its cardiovascular complications. We report the case of 2 siblings: it illustrates the phenotypic variability that might be observed in a same family, the phenotype evolution with age and the diagnosis challenge in childhood.