In a thirty one-year old male patient, we observed spontaneous early onset bilateral lens dislocation into the vitreous body when he was five years old, and late onset right retinal detachment and choroidal detachment , accompanied with congenital atrial septal. There was no lens induced posterior uveitis or glaucoma in either eye for 26 years, which demonstrated that lens dislocation into the vitreous body can be present for a long time without causing any intraocular inflammation. In order to distinguish Marfan syndrome (MFS) from Loeys Dietz Syndrome (LDS), we screened FBN1 and a recurrent mutation, c.364C>T in exon 4 was detected, which resulted in p.Arg122Cys. It is the first genetically confirmed case of choroidal detachment and atrial septal defect in MFS |