11th May 2000

Genetic mapping of the Down's syndrome chromosome

Down's syndrome is one of the most complex of all human genetic disorders, involving problems ranging from mental retardation to heart defects and cancer. It’s been known for years that sufferers inherit a surplus copy of Chromosome 21, but why this leads to so many diseases has been so far a mystery. Now, scientists are hoping that the complete code of Chromosome 21 will allow them to pinpoint the individual genes responsible for each Downs Syndrome disease and perhaps even design therapies.

Down's syndrome: a human genetic disorder that results in physical abnormalities and limited mental ability in those who suffer with it. A syndrome is a medical condition that has a particular group of symptoms.

genetic disorders: problems or illnesses which are passed down from one generation to the next

mental retardation: caused when the brain develops more slowly than usual

surplus copy of Chromosome 21: A chromosome is a part of a cell containing genes which determine its characteristics. People with Down's syndrome have an extra set of this chromosome

code: the way in which information is stored in chromosomes

pinpoint: if you pinpoint something you discover or explain exactly what it is

therapies: ways of treating the syndrome

Chromosome 22 was announced in December; Chromosome 21 is being announced today and the rest will be done in the next year or so. And this will bring us to a final gold standard product of the human genome fully and publicly available for all to use for biomedical research.

in the next year or so: within 1 or 2 years - without being specific

gold standard product: something that others can use that will be of great value as it is so reliable

human genome: the genes that form human beings

biomedical: research into biology and medicine