FBN1 mutations also cause a group of disorders called fibrillinopathies type 1 which include ectopia lentis, Weill-Marchesani syndrome, familial ascending aortic aneurysms and dissections, Shprintzen-Golden syndrome, MASS phenotype, kyphoscoliosis, isolated skeletal features, familial arachnodactyly, neonatal MFS (nMFS), the most severe phenotype of MFS. The gene discussed is FBN1; the disease is Marfan syndrome.