2Hacettepe Üniversitesi, Moleküler Biyoloji A.D., Ankara A number of eye diseases affecting human have been described. The eye diseases occupy an important group among monogenic and complex hereditary diseases. Inherited retinal degenerations include a wide spectrum of diseases extending from retinitis pigmentosa (RP) to macular degenerations (MD). The molecular pathology of the inherited retinal degenerations is one of the hot research topics in recent years. Over one hundred diseases related with retinal degenerations have been listed in OMIM (Online Mendelian Inheritance in Man). By advanced molecular genetic methods, great progression have been achieved in both cloning and understanding the functions of the retinal disease causing genes. As a result of research performed in this area, a high number of genes were found to be responsible for retinal degenerations, however the molecular pathology of most of these diseases are still unknown.
Up to date, 166 loci and 116 genes in these loci have been identified for different types of retinal degenerations. Additionally, the identification of different types of mutations in identified genes increase the genetic heterogeneity of these diseases. The gross number of genes to be studied for retinal degenerations makes research difficult. All the genes and the functions of their protein products in the cell should be understood for the elucidation of the molecular basis of inherited retinal degenerations. The allele frequencies and mutation profiles of the disease causing alleles must be defined by genetic studies in order to give genetic counseling to affected families.
In this review, retinal degeneration causative genes and diseases in this group are classified and recent advances are outlined from molecular genetic point of view.
Keywords : Inherited retinal degenerations, molecular genetics, retina, retinitis pigmentosa