Scientists unravel cancer patient's DNA

SCIENTISTS have decoded the complete DNA of a cancer patient for the first time, tracing the disease to its genetic roots, it was revealed yesterday.

The team were able to sequence the entire genome – the set of genetic information in an organism – of a patient with leukaemia who died from the disease.

They also decoded the genetic information from her cancer cells to identify the changes unique to her disease.

The researchers, writing in the journal Nature, said the study was the starting point for an even more detailed examination of DNA to unravel the genetic basis of cancer.

Dr Richard Wilson, the director of Washington University's Genome Sequencing Centre, said: "Our work demonstrates the power of sequencing entire genomes to discover novel cancer-related mutations.

"A genome-wide understanding of cancer, which is now possible with faster, less expensive DNA technology, is the foundation for developing more effective ways to diagnose and treat cancer."

The researchers found just ten genetic mutations in the DNA of the patient's tumour that appeared to be linked to the disease.

Eight of these were rare, and occurred in genes that had never previously been linked to leukaemia. Virtually every cell in the tumour contained nine of the mutations.

The scientists said they suspected that all the mutations were important to the patient's cancer.

Lead researcher Dr Timothy Ley said: "We felt the answers to why this patient had acute myelogenous leukaemia had to be embedded in her DNA."

The researchers are now sequencing the genomes of other patients with the same disease, and have plans to genetically examine other cancers.