Genetic testing - Eye
Research into genetic testing for inherited retinal dystrophies
Overview
Genetic disorders account for over half of childhood visual disability. Finding genes that cause these conditions has been highly successful with major scientific benefits. However, this also creates a need for genetic testing to support management of affected patients and families.
Problem
Inherited retinal dystrophies are a diverse group of disorders affecting around 1 in 3,500 individuals. Retinitis pigmentosa is perhaps the best known of these conditions.
They cause retinal degeneration leading to severe visual impairment for which there is no effective prevention or cure. Over 100 genes have now been identified that cause retinal dystrophy and genetic testing is becoming standard practice to complement ophthalmic evaluation.
There is a need for clinical services to be developed to ensure patients and their families have access to information and make the best possible adjustment to their eye condition.
It is essential that the NHS widens access to genetic testing and includes testing for patients affected by, and at risk of, disorders that may be caused by a genetic change in one of many possible genes.
Since 2005 our researchers have developed a national service in genetic testing for inherited retinal dystrophies. However we found that there was an imbalance of access to these services. This means an effective evidence-based model of care provision for families with genetic eye diseases needed to be created.
What we aim to achieve
Our data demonstrates increased demand for testing. However, a key barrier to the uptake of genetic testing in the UK is local budgetary constraints, which mean that ophthalmic testing may not always receive the appropriate priority.
The majority of referrals are accompanied by post code of residence and we have monitored referral patterns to assess equity of service provision. While our data demonstrates an encouragingly wide geographical spread of referrals, there are regions which remain underrepresented, such as around Southampton, Northern Ireland, the South West of England and Wales, The lack of an evidence base to support genetic testing means that patients with retinal dystrophy may not gain access to testing.
The development of a model for the delivery of genetic testing will result in improved professional awareness of patient need and access to genetic testing. We believe that the inequalities in clinical services result in part from this lack of awareness and evidence base, and aim to tackle this problem. Patients and lay groups have, and will continue to be, fundamental to the design and translation of the programme.
What we have achieved to date
Over recent years our researchers have developed genetic testing for the NHS in the areas of X-linked autosomal dominant retinitis pigmentosa and autosomal dominant macular dystrophies.
This testing has now been adopted as part of the UK Genetic Testing Network’s approved diagnostic tests. It was agreed that the service for retinitis pigmentosa should be adopted for provision as a national NHS service from 1st April 2008.
Our wider research programme, funded by Fight for Sight, aims to develop a patient led, evidenced-based model for providing clinical services to families with inherited retinal dystrophy. This requires interviews with patients and health professionals to create an optimum care model to be tested within an exploratory trial.
As part of an expert working group (Moore and Burton), our findings were confirmed and it was recommended that research be undertaken to examine the most effective model.
