The summary of the following study presents several genotypic and phenotypic characteristics of autosomal dominant retinitis pigmentosa. This studies also attempt to describe the physiology and the progression of the disease, paying specific attention to different mutations of the RHO gene. Since RHO codes for rhodopsin, one of the unifying characteristics seen in patients with mutations in this gene is degeneration of rods (vision in low light) before the degeneration progresses to the cones. This relays into the first sign of retinitis pigmentosa which is loss of night vision and inability to navigate in low light. Young patients begin seeing blind spots in their peripheral vision as the disease gets progressively worse. The development of retinitis pigmentosa could halt at this stage however, in the majority of cases it continues to the cones and central vision begins to fail as well. In adults, retinitis pigmentosa can lead to permanent, legal blindness (Retinitis Pigmentosa, 2018). In an early study performed by Ching-Hwa Sung et al, the researchers found rhodopsin mutations in autosomal dominant retinitis pigmentosa as well (1991). They screened 161 unrelated patients with this particular mode of inheritance for point mutations in the rhodopsin gene by using PCR and gel electrophoresis. Of the 161 patients, 39 were found to carry one of 13 different point mutations at 12 amino acid positions of rhodopsin and the “presence or absence of the mutations correlated with the presence of absence of retinitis pigmentosa in 174 out of 179 individuals tested in 17 families” (Ching-Hwa Sung, 1991). These point mutations were found in the coding sequences of the RHO gene and the most common allele, P23H, was found in 15% of the ADRP families. The individual family members also experienced gradual loss of night vision and navigation in the dark. Since this is such a low, unexpected percentage, it could be concluded that there is delayed onset of the disease or very mild disease expression. This study emphasizes how with each genetic type (autosomal recessive, autosomal dominant, X-linked) there is marked individual variation. Any particular mutation in a gene, such as the rhodopsin gene RHO, is unlikely to be present in other genetic types. This presents a setback that is faced in many attempts to create treatments/cures for retinitis pigmentosa. Because of the specificity and individualism of the gene the current progress of treatment plans is very complicated and requires special attention to the patients’ conditions
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