FBN1 and Marfan syndrome: Mutations in the FBN1 gene are known to cause Marfan syndrome, and a number of studies have linked homozygous mutations in the LTBP2 gene with a syndrome including megalocornea, microspherophakia, lens dislocation, and secondary glaucoma developing after the age of 3 years [23] and in isolated microspherophakia/lens dislocation [24].