Eyeworld

EW CATARACT 37 December 2016 "As these complications tend to appear over the long term, it is im- portant for patients to have regular follow-ups," he said. Nipping it in the bud New technologies may be the key to reversing microphthalmia and its myriad of complications. Dr. Borroni cited work by Hung et al. that stud- ied genome engineering through the application of clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated protein (Cas) systems. 1 This technol- ogy enables accurate and efficient genome editing, which could result in imminent clinical application, much to the benefit of people with inherited eye diseases, such as mi- crophthalmia. Microphthalmia is caused by mutations in several different genes that are involved in early eye de- velopment, many of which are still unidentified, or by a chromosomal abnormality affecting one or more genes. A mutation in the SOX2 gene has been associated with microph- thalmia, which is inherited in an autosomal dominant manner. "The use of genetics in clinical diagnosis is increasing, and we may only be a few years away from using CRISPR/Cas9 technology to help us become 'DNA surgeons,' in particu- lar for corneal diseases," Dr. Borroni said. Dr. Borroni and his team in- vestigated the DNA of the 14 study patients to determine the presence of known gene mutations. They extracted genomic DNA from blood and amplified the SOX2 coding region. Afterward, they sequenced PCR products with BigDye Termi- nator v. 3.1 (Applied Biosystems, Foster City, California) and con- firmed the identified gene mutations by additional independent PCR and sequencing experiments. The tests revealed that SOX2 mutations appeared in three out of the 14 pa- tients (15%). "The SOX2 gene has been identified as a major causative gene of microphthalmia. We screened our patients to establish the frequency of SOX2 in the research group, and the mutation was observed in 15% of the patients with congenital cat- aract. Further studies of mutations affecting the lens membranes, aqua- porins/M, Lim-2, and connexins, or addressing the structural proteins of the cytosol will give a better under- standing of congenital cataract in developing eyes," he said. EW Reference 1. Hung SS, et al. Genome engineering in ophthalmology: Application of CRISPR/Cas to the treatment of eye disease. Prog Retin Eye Res. 2016;53:1–20. Editors' note: Dr. Borroni has no finan- cial interests related to his comments. Contact information Borroni: info.borroni@gmail.com NOW IN SINGLE-USE ! by DIAMATRIX IRIS SPECULUM 6.7mm near-circular dilation 30 day trial available, call 800.867.8081 No Pinching, Easily Rotates Visit our website Diamatrix.com for additional information

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