Genotype And Phenotype Studies In Patients With Vitelliform Macular Dystrophy

Part1Genotype and Phenotype studies in Patients with Best Vitelliform Macular DystrophyPurpose The purpose of this study is to investigate the phenotype and genotype in Chinese patients with Best vitelliform macular dystrophy (BVMD).Methods Sixteen subjects from4Chinese families and1single patient with BVMD were screened for mutations in Bestl gene by direct sequencing, and underwent complete ophthalmologic examinations.Result Eight patients including2females were diagnosised as BVMD, with the average onset age22.1and the fundus lesions ranged from normal to vitellirupture. Two previously reported missense mutations(Thr6Arg%Ser16Phe) as well as4gene polymorphisms (-221T>C、109T>C、219C>A、1608T>C) in Bestl gene and1novel missense mutation (-222G>A) in FTH1gene were identified. One missense mutation in FTH1gene was identified in2patients with only gene polymorphisms in Bestl gene. Only gene polymorphisms were found in1patient with typical BVMD features and reduced EOG Arden ratio.Conclution Heterozygous mutations and gene polymorphism in Bestl gene are general in Best vitelliform macular dystrophy patients. FTH1gene could mediate the pathogenesis of BVMD by regulating gene expression at the level of RNA stability or oxidative decomposition of polyunsaturated fatty acids in retina. Gene polymorphisms in some hotspot regions of Bestl gene could also cause clinical characteristics。 Part2Genotype and Phenotype studies in Patients with Adult-onset Vitelliform Macular DystrophyPurpose The purpose of this study is to investigate the phenotype and genotype in Chinese patients with adult-onset vitelliform macular dystrophy (AVMD).Methods Five patients with AVMD and1family member were screened for mutations in Bestl gene and Peripherin/RDS gene by direct sequencing, and underwent complete ophthalmologic examinations.Result Five patients were diagnosised as AVMD, among which2were involved in both eyes and1showed pattern dystrophy in the fellow eye. The EOG Arden rate were normal except2ones with slightly reduce. One neomissense mutations(Ala337Thr) as well as4gene polymorphisms (318T>C、910C>G929G>A、1013A>G) in Peripherin/RDS gene and3reported gene polymorphisms (-221T>C、109T>C1608T>C) in Bestl gene were identified.Conclution Adult-onset vitelliform macular dystrophy owns moderate symptoms and an indeterminate genetic inheritance. The genes encoding RDS and Bestl have been implicated in some cases of AVMD. AVMD is often asymptomatic at the initial stages and the characteristic lesions may disappear over time as atrophy of the outer retina progresses, inducing misdiagnosis as Best disease、pattern dystrophy and eventually atrophic age-related macular degeneration.