Abstract
Purpose:
The aim of this study was to analyze ocular involvement in patients diagnosed with the Marfan syndrome, study their clinical course and prognosis based on the type of FBN1 mutation, and possibly indicate a genotype-phenotype correlation.
Methods:
Observational study of 12 patients, (8 male and 4 female, median age 35, range 6 to 65) diagnosed with the Marfan syndrome. The patients included in the study all met the Ghent criteria and in 9 cases the diagnosis was confirmed with genetic testing. In all patients a complete ophthalmologic examination was performed. We evaluated the clinical data, the incidence of ectopia lentis and other eye disorders. We analyzed the association of ocular signs with the type of mutation.
Results:
Of the 12 patients 11 (91.67%) had myopia, four (33.3%) had ectopia lentis, of which three developed secondary glaucoma (25%). Other ocular abnormalities found were strabismus (16.67%), retinal tears (8.33%), retinal detachment (8.33%), congenital cataract (8.33%), and amblyopia (8.33%). We encountered three classes of mutations in our patients: the most frequent comprised mutations resulting in a premature termination codon (PTC, nonsense mutations) found in 7 patients (c.7180C>T in 3 patients, c.3795T>A in 2 patients, c.5493C>G in 1 patient, and c. 5863delC in 1 patient), one patient with a missense mutation (c.504C> G), and one patient with aberration of splicing (c.1468 +5 G>A). Of patients with ectopia lentis one (1 eye) had a nonsense and one (2 eyes) a missense mutation.
Conclusions:
Myopia was the most frequent ocular involvement, affecting almost all patients. In our group PTC mutations of the FBN1 gene revealed to have a smaller risk of ectopia lentis, as observed in previous reports. Within the missense mutations ones affecting calcium binding sites and cysteine substitutions are probably associated with a more severe ocular involvement. The prevalence and severity of ocular involvement in relation with the type of FBN1 mutation, and especially the broad spectrum of ocular manifestations in patients with the same mutation is still poorly understood. Therefore more studies are required to explain the genotype-phenotype correlation, which could serve in the direction of appropriate medical treatment and monitoring.
Keywords: 539 genetics •
605 myopia