[Life without DNA repair].

BACKGROUND

Faithful maintenance of the genomic information is crucial for the survival of a species. Consequently, DNA repair processes must have evolved early during evolution. DNA damage left unrepaired might cause mutations leading to cell death, increased cancer incidence and severe syndromes.

MATERIAL AND

METHODS

In 1968, for the first time a link was found between a human syndrome, xeroderma pigmentosum, and a defect in the machinery for DNA repair. These patients develop skin cancer at an early age if not completely protected against sunlight. More recently, several other DNA repair syndromes with cancer predisposition and premature aging have been identified.

RESULTS

A number of DNA repair genes causing such defects have now been cloned and characterised. These genes represent different DNA repair pathways and some of them are involved in the coupling between DNA repair and DNA transcription.

INTERPRETATION: It is now possible to produce mice models with defects identical to those identified in humans. During the last 5 years, more than 100 mice models with DNA repair deficiency have been produced. Further characterisation of such mice will provide a unique opportunity for understanding the clinical picture caused by altered DNA repair capacity, and also elucidate the complex interaction of different DNA repair genes.