FBN1-related Marfan syndrome (Marfan syndrome), a systemic disorder of connective tissue with a high degree of clinical variability, comprises a broad phenotypic continuum ranging from mild (features of Marfan syndrome in one or a few systems) to severe and rapidly progressive neonatal multiorgan disease. Cardinal manifestations involve the ocular, skeletal, and cardiovascular systems. Ocular findings include myopia (>50% of affected individuals); ectopia lentis (seen in approximately 60% of affected individuals); and an increased risk for retinal detachment, glaucoma, and early cataracts. Skeletal system manifestations include bone overgrowth and joint laxity; disproportionately long extremities for the size of the trunk (dolichostenomelia); overgrowth of the ribs that can push the sternum in (pectus excavatum) or out (pectus carinatum); and scoliosis that ranges from mild to severe and progressive. The major morbidity and early mortality in Marfan syndrome relate to the cardiovascular system and include dilatation of the aorta at the level of the sinuses of Valsalva (predisposing to aortic tear and rupture), mitral valve prolapse with or without regurgitation, tricuspid valve prolapse, and enlargement of the proximal pulmonary artery. Severe and prolonged regurgitation of the mitral and/or aortic valve can predispose to left ventricular dysfunction and occasionally heart failure. With proper management, the life expectancy of someone with Marfan syndrome approximates that of the general population.

A rare, genetic, lens position anomaly disease characterized by bilateral congenital blepharoptosis, ectopia lentis and high grade myopia. Additional reported manifestations include abnormally long eye globes and signs of levator aponeurosis disinsertion. There have been no further descriptions in the literature since 1982.

A rare genetic eye disease with characteristics of microcornea, coloboma of the iris and the optic disc, axial enlargement of the globe, staphyloma and severe myopia. Additional manifestations are mild cornea plana, iridocorneal angle abnormalities with elevation of intraocular pressure and shallow anterior chamber depth. Variable expressivity of the phenotype has been described, including unilateral or bilateral involvement or variable extent of coloboma among other features.

Myopia, or nearsightedness, is a refractive error of the eye. Light rays from a distant object are focused in front of the retina and those from a near object are focused in the retina; therefore distant objects are blurry and near objects are clear (summary by Kaiser et al., 2004). For a discussion of genetic heterogeneity of myopia, see 160700.

Myopia-27 (MYP27) is characterized by early-onset high myopia with increased axial lengths. Fundus changes include optic nerve head crescent and tigroid appearance of the posterior retina (Ouyang et al., 2019).