Objective To analyze the relationship between genotype and phenotype of vitelline macular dystrophia (VMD2) gene in a family with Best disease, and to provide the theoretical basis for gene diagnosis of Best disease. Methods Mutation in the coding regions and the promotor sequence of VMD2 gene from 10 members in a family with Best disease were screened by polymerase chain reaction (PCR) and direct DNA sequencing, and combined with a conformation sensitive gel electrophoresis (CSGE) approach, VMD2 gene screening was performed on 100 normal control individuals. Results In the 10 members, Trarr;C nucleotide change at the 223 base of exon 3 was detected in 9, including 6 with Best disease who was confirmed by ophthalmoscopy and electrophysiological examination in whom 2 were affirmed as having homozygote of this mutation. Other 3 young family members with VMD2 gene mutation only had abnormal electro-oculogram manifestations. Above mutation was not detected in the normal control individuals. Conclusions The phenotype and genotype of VMD2 in the family with Best disease is highly correlated. Mutation in VMD2 gene is the nosogenesis in this family. Mutation screening of VMD2 gene can be used for genic diagnosis and genetic consultation of Best disease. (Chin J Ocul Fundus Dis, 2006, 22: 86-89)
Autosomal recessive Best disease (ARB) is a rare clinical fundus disease caused by BEST1 mutation. The critical features of ARB are the presence of multifocal subretinal yellowish lesions, which corresponding to the hyperfluorescent spots on FAF, scattered over the posterior pole of the retina, absent of typical vitelliform lesions in the macula. Imaging of OCT is often manifested as subretinal or intraretinal fluid, and cystoid macular edema, and hypereflective focus at RPE level. EOG shows an absent or severely reduced light rise (decreased value of Arden), which often accompanied by reduction and delay of the rod and cone ERG. Some patients with ARB show hyperopia, short axial length and shallow anterior chambers, with a corresponding high incidence of angle-closure glaucoma. Though there isn't any effective therapeutic methods of ARB at present, prevention and treatment for its complications such as angle-closure glaucoma and choroidal neovascularization should be considered. Present study about ARB mainly focus on some retrospective cases, and ARB is often misdiagnosed with Best vitelliform macular dystrophy, central serous chorioretinopathy and other fundus diseases in clinic. A detailed understanding of the clinical features and genetic characteristics of ARB might be helpful in clinical diagnosis and treatment. Research with larger sample size are expected to further investigate the different stages of ARB and its developing process, the potential pathological mechanism, the relationship between genotype and phenotype, so as to improve the understanding of the disease.