P R E S S R E L E A S E
More than 6,000 human diseases are known to be determined genetically and over 3,000 disease causing genes have been identified already. Many eye diseases are also known to have genetic components and mutations in specific genes have been identified. Some gene mutations are simply alterations of one base pair among the total three billion base pairs of DNA in the human gnome. However, most of these eye diseases are multi-factorial in etiology, i.e., they are caused by complex and interactive effects of personal factors, environmental conditions and gene aberrations.
The Department of Ophthalmology & Visual Sciences of The Chinese University of Hong Kong has been researching on genetic eye diseases for 2 years. Earlier this year a "Genetic Eye Clinic" was established at the Prince of Wales Hospital to look after patients with genetic eye diseases and their family members. Complete eye examination, treatment and genetic counseling are offered. Many of them gave consent for partaking in the Department's study by giving a small amount of blood, less than 3 ml. More than 1,000 specimens have been collected. Advanced techniques of molecular biology by a systemic and comprehensive approach, including polymerize chain reactions and DNA sequencing were applied for analysis of the samples. Genetic eye diseases under study include some very common ones as well as some rare diseases in Hong Kong and many patients with these diseases would develop serious clinical complications, such as blindness, if not detected and treated early enough. The followings are the eye diseases being studied:
1. Aged Related Macular Degeneration (ARM): leading cause of blindness
in the elderly in the Western
world;
2. Primary Open Angle Glaucoma (POGO): Glaucoma is the leading cause
of blindness in Hong Kong;
3. High Myopia (short-sightedness of > 600 degrees);
4. Congenital Hypertrophy of the Retinal Pigment Epithelium (CHIRP)
in patients with Familial
Adenomatous Polyposis (FAA);
5. Anterior Segment Dysgenesis including Aneroid, Peter's anomaly and
Reign's syndrome;
6. Leper's Hereditary Optic Neuropathy (HON);
7. Retinitis Pigments (RP);
8. Stargardt's disease; and
9. Diabetic Retinopathy.
Dr Denies S.C. Lam, Chairman of the Department, directs the research and Professor Calvin CP.. Pang, a professor of the Department, takes charge of the laboratory investigations. Till now, 4 new mutations-- 2 in glaucoma, 1 in aneroid and 1 in FAA with CHIRP-- that have not been reported in the world medical literature before were identified. A number of mutations that have been previously reported to be occurring in Caucasian and Japanese patients were also found.
The research team expects in the coming one to two years a large amount of important genetic data with clinical values will be obtained. The results will cast light on the mechanisms of pathogenesis of genetic eye diseases, which is of immense value on the advancement of scientific knowledge. The research work is also of specific important clinical values to patients and their family members. By detecting carriers of disease causing gene mutations in artist individuals, some eye diseases could be prevented by avoiding the environmental risk factors. For example, the risk of developing aggregated macular degeneration (ARM) will be reduced by avoiding a high cholesterol diet, smoking and excessive sunlight exposure in ARM gene carriers. On the other hand, early and regular eye check-up for gene carriers, for instance in primary open angle glaucoma (POGO) will enable detection of the eye disease early enough that timely and appropriate treatment can prevent deterioration of the eye conditions, leading to a more favorable final clinical outcome.
For patients and artist individuals that are interested to participate in our genetic study, please refer to the enclosed table and contact the Department of Ophthalmology & Visual Sciences of The Chinese University of Hong Kong through the following hot lines:
- Tel: 2645 0568
- Fax: 2648 3856
- E-mail fionlau@cuhk.edu.hk
.