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WASHINGTON, April 14: Following is a glossary of terms used in genetic research:
GENOME: The chemical code needed to build a living creature, whether plant, animal or human. The blueprint comprises DNA (deoxyribonucleic acid), a long molecular chain of phosphate and sugar in the shape of a double-helix ladder connected by rungs, called bases. A first draft of the genome for humans was published on June 26 2000.
CHROMOSOME: The microscopic, threadlike part of the cell that carries hereditary data in the form of genes.
GENE: Sections in the DNA chain that determine the synthesis of proteins, which govern all the life processes. The term gene derives from the Greek word “genos,” for birth or origin.
SEQUENCING: A reading of the DNA bases, which comprises strings of compounds designated by the letters A, C, G and T (adenine, cytosine, guanine and thymine). Sequencing requires breaking down the DNA into small segments and then reassembling the data.
PROTEINS: Substances controlled by genes that make up virtually all of the body’s ingredients and are also responsible for switching genes on and off.
GENETIC MEDICINE: Malfunctioning genes have been linked with a thousand disorders, ranging from heart disease, diabetes and asthma to cancer, obesity and Alzheimer’s. Doctors hope to use the genome to devise medicines that block the working of a flawed gene, thus causing a disease to be stopped or reversed. These treatments many years ahead. The first step will probably be diagnostic tools to spot genetic predisposition to a disease.
GENE THERAPY: A highly experimental approach in which a baulky gene is replaced with a correct one. The new gene is delivered like a Trojan horse. It is tucked inside a disabled virus, which goes around the body, “infecting” cells with the replacement genetic programme. So far, the treatment has worked triumphantly on several babies with immune deficiency disorder, but went tragically wrong with the death of a young American man with a severe liver disorder. This has raised questions about how much is known about the complex interaction between genes. —AFP
