The revised ghent nosology; reclassifying isolated ectopia lentis

Inherited ectopia lentis ( EL ) is most commonly caused by Marfan syndrome ( MFS ), a multisystemic disorder caused by mutations in FBN1 . Historically the diagnosis for patients with EL who have no systemic features of MFS is isolated EL ( IEL ). However, the Ghent nosology for MFS was updated in 2010 and made some important alterations. In particular, patients with EL and a FBN1 mutation are now categorically diagnosed with MFS , if their mutation has previously been described with aortic dilation/dissection. This carries significant systemic implications, as many patients previously diagnosed with IEL are now reclassified. We provide a review of all published cases of IEL caused by FBN1 mutations over the last 20 years to assess what impact the new Ghent nosology has on these. Indeed, 57/123 probands (46.3%) are now classified as MFS according to the revised Ghent nosology and 37/96 mutations (38.5%) reported to cause isolated EL have also been found in patients with aortic dilation/dissection. These findings suggest that EL caused by mutations in FBN1 is actually part of a spectrum of fibrillinopathies with MFS , and the term ‘IEL’ should be avoided in such cases.