[Applying molecular biology techniques to ophthalmologic research].

EDITORIAL At present there are over 990 registered hereditary diseases involving only the eye or in the context of a disease involving other organs (1). Aniri-dia, primary congenital glaucoma, retinoblastoma, Leber's neuropathy or uveal melanoma are but a few examples. In some cases, the involvement is attributed to a mutation in a specific gene; in others, it is related to changes in different DNA sequences which increase vulnerability against the disease. Sometimes, the hereditary disease is in fact a group of diseases transmitted with different hereditary patterns which involve dozens of loci (for instance, pigmentous retinitis). Molecular biology offers a high number of applications for medical research and particularly for basic, clinical and applied ophthalmological research. It provides the possibility of studying diseases of genetic origin in order to find genetic variability and proteic expression patterns allowing for a greater knowledge about the disease and to assist a more precise diagnosis, prognosis or enhanced therapeutic approaches. For instance, the DNA sequence analysis in specific regions of the genome and the determination of variants in the arrangement of one or more nucleotides (polymorphisms) constitutes a very useful tool for diagnosing ocular diseases in populations or family groups. By selecting organisms undergoing a spontaneous mutation, or after the external manipulation of DNA (as explained below), animal models have been obtained for analyzing the molecular mechanisms which underlie a nosological entity (2). In addition, this tactic opens the doors for somatic gene therapy which aimed at restoring functions which are absent, weakened or altered in a gene or group of genes. It is clear that, throughout its development, molecular biology has provided very useful methodolo-gical tools for ophthalmologists. DNA, the molecule in charge of transmitting genetic information, carries out a basically passive role. The proteins derived from its expression are in charge of carrying out the myriad of life-sustaining reactions. Precisely for this reason it is essential to advance the knowledge of proteic functions. Mutant organisms have provided some keys to unravel the function of proteins. Traditionally, mutations were obtained by treating with mutagenic agents such as specific chemical substances or radiations. In addition, it is possible to produce specific mutants by inserting in a living organism copies of altered or nonfunctional genes to analyze the changes in the behavior or development of said organism. These experiences have been carried out with a variety of organisms. However, taking into account that the mouse …