Parisha T, B. Optom Student
Dhanalakshmi Srinivasan University, Trichy, India
Scientists have counter-plotted numerous genes and their variants that can impact the vision and health of our eyes. In short, recent advances in genomics have led to the identification of new genes and variants responsible for a host of inherited and sedentary conditions in ophthalmology. Specialty vision impairment is anticipated to rise as conditions that have measurable inheritable factors continue to grow. (1)
Genetic Factor in Eye Development
Paired Box 6 (PAX6) and other homeobox genes are essential for the early stages of eye formation. It is responsible for controlling the anatomy and function of the eye. The differentiation and development of the different tissues of the eye depend on the EYA, SIX, and Rx genes. Fibroblast-Grown Factor, or FGF, is necessary for development and differentiation. The function of Sonic Hedgehog (SHH) in ocular patterning, retinoids were involved in the development of the primary vitreous, corneal, iris, and ciliary stroma, which are eye structures made of cells derived from the neural crest. The neuroepithelium of the optic cup of chick embryos had most of the transcripts of the fibroblast growth factor receptor type 1, while the neural crest-derived mesenchymal cells surrounding the optic cup contained the transcripts of the type 2 receptor. The type 3 receptor, on the other hand, was mostly expressed in lens vesicles, indicating that all three fibroblast growth factor receptors. (2)
Hereditary Eye Disorder
Retinal dystrophies, including Retinitis Pigmentosa (RP), are a diverse collection of illnesses caused by abnormalities in genes that code for rod proteins. Inherited dystrophies are the epiphenomenon of a complicated syndromic RP. (3)
Macular dystrophies are typically inherited in either an autosomal recessive or autosomal dominant pattern, depending on the specific type of dystrophy. Stargardt’s disease is an example of autosomal recessive inheritance. Vitelliform macular dystrophy is an example of an autosomal dominant inheritance condition. Cone-rod dystrophy is an example of X-linked inheritance. (1)
Figure 1: Image showing impact of genetic mutations on eye development
Image Courtesy: Created by the Author
Common Eye Diseases with Genetic Influences
Increases in nucleotide polymorphisms and Nitric Oxide Synthase 2A (NOS2A) were found in Age-related Macular Degeneration (AMD). Gene mutations and heterogeneity have been noted in cataracts. (1,4) It is frequently noted that children of parents who wear glasses also wear glasses. (5)Common eye diseases are now known to be influenced by a wide range of hereditary and environmental variables. The development of the disease may be influenced differently by endogenous and external factors, such as age, free oxygen radicals, toxic environmental agents, genetic predisposition, and other factors. (6)
Genetic Testing for Eye Diseases: Advances and Future Directions
Several types of genetic testing are used to diagnose and manage eye diseases. Such tests are cytogenetic tests, gene screening tests, DNA microarrays, and DNA sequencing. Genomic analysis is improving the accuracy and efficiency of genetic testing. Gene editing, such as CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated protein 9 (Cas9)). It is for the treatment of eye disease. (1)
Conclusion
Genetics plays a significant part in determining our eye health. Environmental factors, lifestyle choices, and healthcare also play important roles. Understanding the genetic basis of eye diseases can help to develop treatments and prevention strategies. Genetic testing and counselling provide information about their risk of developing eye diseases.
References
- Singh, M., & Tyagi, S. C. (2018). Genes and genetics in eye diseases: a genomic medicine approach for investigating hereditary and inflammatory ocular disorders. International journal of ophthalmology, 11(1), 117.
- Matsuo, T. (1993).The genes involved in the morphogenesis of the eye. Japanese journal of ophthalmology, 37(3), 215-251.
- Ferrari, S., Di Iorio, E., Barbaro, V., Ponzin, D., S. Sorrentino, F., & Parmeggiani, F. (2011). Retinitis pigmentosa: genes and disease mechanisms. Current genomics, 12(4), 238-249.
- DeAngelis, M. M., Owen, L. A., Morrison, M. A., Morgan, D. J., Li, M., Shakoor, A., … & Farrer, L. A. (2017). Genetics of age-related macular degeneration (AMD). Human molecular genetics, 26(R1), R45-R50.
- Harb, E. N., & Wildsoet, C. F. (2019). Origins of refractive errors: environmental and genetic factors. Annual review of vision science, 5(1), 47-72.
- Sacca, S. C., Bolognesi, C., Battistella, A., Bagnis, A., & Izzotti, A. (2009). Gene–environment interactions in ocular diseases. Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 667(1-2), 98-117.