CCP Pang, L Baum, DSC Lam

Formation of the human eye involves complex and interactive processes of molecular and cellular development of the neural and surface ectoderm. These biological developments are essentially all governed by genes. Monogenic eye diseases are often caused by the loss of normal function of genes, due to sequence aberrations or hypermethylation. Most of the common eye diseases, however, are multifactorial in etiology and attributed to a multiple and interactive genetic and environmental factors. Age-related macular degeneration has been reported to be associated with APOE genotype and mutations in the ABCR and ARMDI genes. Age, smoking, intake of saturated fats and exposure to sunlight are risk factors. More than 20 chromosomal loci and 8 candidate genes have been identified for retinitis pigmentosa, which is variable in phenotypic expression. Multiple genetic determinants and secondary factors are also known to be associated with most forms of cataract and glaucoma. Myopia occurs in many ocular and metabolic disorders. Recent genome-side searches have revealed two possible loci on chromosomes 12q and 18p. We are in the process of establishing a database for gene mutations of common eye diseases in Chinese. A wide spectrum of novel and previously reported gene aberrations has been obtained.