Eyeworld

105 EW INTERNATIONAL October 2015 further knowledge on the genetic basis of congenital cataracts are gathered, clinicians may be able give more accurate predictions on how cataracts may progress and what the surgical outcomes will be. Further- more, genetic testing can hopefully help elucidate more complex cases, especially those with late-onset symptoms. "Our test looks at all of these genes in parallel, so patients can be diagnosed much faster and receive the treatment, clinical management and genetic counseling they need," said Dr. Gillespie, study author and developer of the genetic test, in a University of Manchester news re- lease. "In some cases, we have iden- tified that the cataracts aren't just a standalone problem, but a symptom of a more complex syndrome; this includes Warburg micro syndrome and galactokinase deficiency, both rare conditions that are probably underdiagnosed, as warning signs in children can be subtle." Though only available in the U.K., other medical facilities can request the genetic test through international referral. The Ameri- can Academy of Ophthalmology's suggestions on inherited eye disease genetic tests encourage clinicians and patients to make an informed decision. Patients should weigh both the benefits and risks, while ophthalmologists who order genetic tests are responsible for providing appropriate genetic counseling to their patients and their families. Research in genomic medicine will not stop at finding the genetic root cause (in this case, of congeni- tal cataract). There are additional re- search and clinical implications. The team from the University of Man- chester believes that as more robust genotype-phenotype correlations are established, in time this will lead to deeper understanding of the mech- anisms leading to the formation of cataracts themselves. EW Editors' note: Drs. Black and Gillespie have no financial interests related to this article. Contact information Black: graeme.black@manchester.ac.uk Gillespie: rachel.gillespie@manchester.ac.uk syndromic congenital cataracts, 63% were found to have potential disease-causing mutations. Impact on patients and their families Being able to determine the exact genetic cause of congenital cata- racts has a huge impact not only in patient outcomes, but also in how clinicians are going to handle the clinical assessment after the initial working diagnosis. This can in turn lead to more suitable management and counseling of patients and their families. However, the researchers em- phasized that accurate diagnosis of congenital cataracts requires a mul- tidisciplinary approach, including a good flow of communication among different departments and specialties in clinical settings. "A typical clinical assessment of a child with congenital cataract involves taking a careful family history to explore the presence of ocular phenotypes and other condi- tions and to gather the details of any antenatal, perinatal, and postnatal problems," they reported. "In partic- ular, this needs to include enquiry about maternal illness and exposure to drugs and other potential terato- gens during pregnancy." In the past, testing genes one by one would have taken years to finish. Now with targeted next-gen- eration sequencing, the diagnosis comes in mere weeks by analyzing mutations in 115 known congeni- tal cataract genes at once. The test, made available in the U.K. since December 2013 through the coun- try's National Health Service, usually takes about 2 months to complete. According to literature, congen- ital cataracts are thought to cause visual loss over a person's lifetime in roughly 200,000 children worldwide per year, making it the number one cause of blindness in children. In the U.K. alone, 2.5 to 3.5 children per every 10,000 who are younger than 15 years of age are affected by congenital cataracts. A targeted genetic test such as the next-gener- ation DNA sequencing is going to have a tremendous impact on these statistics in the near future. The researchers also noted that as more patients get tested and

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