chromosome 8

• autosome
• medium sized chromosome
• about 146.000.000 base pairs
• about 984 genes

The WRN gene encodes the Werner protein, which is involved in the repair and replication (making copies of DNA for cell division) of DNA. WRN mutations cause the Werner syndrome. It is supposed that cells with an altered Werner protein may divide less often than normal and that DNA damage is allowed to accumulate. This results in a dramatic, rapid ageing after reaching puberty. People affected by Werner syndrome have a short stature with thin arms and legs and show symptoms of ageing such as loss and greying of hair, cloudy lenses (cataracts) or

thinning bones (osteoporosis) much earlier than normal and reach only an age of about fifty years.

The POLB gene: In eukaryotic cells, DNA polymerase beta (POLB) performs base excision repair required for DNA maintenance, replication, recombination (shuffling of alleles (viable DNA codings with a given locus (position) on a chromosome)) and drug resistance.