PEDIGREE KEY TO IDENTIFYING PAEDIATRIC GENETIC EYE DISORDERS

As a paediatric anterior segment surgeon, Ken K Nischal MD, FRCOphth has a big interest in genetics. The corneal diseases, glaucoma and cataracts he treats in children often result from genetic abnormalities – but busy practising ophthalmologists can be hard pressed to identify them. So given the chance to collaborate on research with high-volume paediatric glaucoma clinics in india, Dr Nischal focused on improving genetic counselling. Through the World society of Paediatric Ophthalmology and strabismus (WsPOs), Dr Nischal, who is director of paediatric ophthalmology at the University of Pittsburgh Medical Centre, Pennsylvania, Us, developed a pilot programme that trains paramedical professionals in the basics of genetic education. Under an institutional review board-approved protocol, Dr Nischal and a student completing studies in ophthalmic genetic counselling at Pittsburgh developed a seven-week online module course distributed through the WSPOS website. 12 clinics in India each chose two paramedical staff members, either optometrists or nurses, to take the course. A baseline survey found a fairly low level of understanding of genetics among participants. Genetics knowledge improved measurably after each module. in July, Dr Nischal travelled to India and met with participants to refine the project.

The biggest issue was defining the role of the paraprofessionals as genetic educators, rather than full-fledged genetic counsellors, Dr Nischal said. As educators they interview patients and provide information to doctors, who counsel patients on their conditions, as well as diagnostic, preventive and treatment options. Incidents of educators counselling patients, for example telling a patient that a defect could have resulted from a consanguineous marriage, were defined as adverse events. The greatest need was for detailed family histories, Dr Nischal said. “Doctors in these huge centres in India are seeing 200 to 300 glaucoma patients a day. They need someone who can do an accurate pedigree so the doctors could pick up possible genetic components.” Results, including whether better access to pedigrees leads to increased diagnosis of genetic components in glaucoma, are being compiled. However, Dr Nischal said the clinics already are identifying more genetic glaucoma cases as well as more cases in which glaucoma is related to a genetic syndrome, such as Axenfeld- Rieger or nail-patella. “It is absolutely clear that they were seeing patients who they felt might have a genetic problem but they didn’t have time to delve into it.” Lessons for the developed world The need for better genetic education and understanding is hardly limited to developing countries.

Dr Nischal pointed out that even in the Us there are just 38 dedicated ophthalmic genetic counsellors, though many general genetic counsellors also address ophthalmic issues. He suggests ophthalmologists routinely do family histories for children with congenital or developmental eye problems. “If you draw a three generation pedigree and see affected people in all three generations, they need a genetic counsellor, and likely this child needs genetic testing,” Dr Nischal said. Because of the complexity and rapid advance of genetic diagnosis, he recommends a referral to a centre with specific ophthalmic experience for genetic tests. “The tests are complicated and sophisticated. it is difficult to know what to test without experienced help,” Dr Nischal said. Genetics information sources n GeneTests – summaries of inherited diseases with links to articles and labs specialising in specific genetic tests around the world, www.gentests.org 

eyeGene – Us NEi program collects genetic samples from ophthalmologists, enabling incorporation of genetic testing and participation in clinical trials, www.nei.nih.gov/resources/ eyegene/asp

Carver Lab – University of iowa provides clinical genetic testing on a wide range of ocular genetic disease, www.carverlab.org

OMiM – Online Mendelian inheritance in Man provides continuously updated overview of peer-reviewed publications on genes, clinical syndromes and mutations, www.ncbi.nlm.nih.gov/entrez/query. fcgidb=OMIM