Mutant gene triggers pancreatic cancer

Scientists have uncovered a mutant gene that may lead to cancer of the pancreas.

Siân Jones and colleagues from the Sol Goldman Pancreatic Cancer Research Center in Baltimore in the US, sequenced the DNA from the tumor of a patient with pancreatic cancer. Their study published in the journal Science, describes how they identified a number of genes in the DNA of the tumor that are not present in a reference human genome of someone not known to have pancreatic cancer.

They then narrowed down their search to a particular gene called PALB2 which is already known to be associated with breast cancer and disease called Fanconi anemia, and which had mutated in this patient by the insertion of a stop codon: a short sequence of DNA that commands a gene to stop being translated into a protein. When a stop codon appears in the wrong place it will cut a protein short so it won't work properly.

To find out whether other people with pancreatic cancer carry the same mutant gene, Jones and her team sequenced the gene in 96 pancreatic cancer patients. Similar mutations in the PALB2 gene were found in three other people. We also know that this mutation is rare in people who don't have pancreatic cancer. A previous study of over a thousand people without cancer found no versions of the mutation.

PALB2 is known to be a DNA-repair gene. A mutation in that gene increases someone's chances of getting cancer because, rather than being repaired, genetic damage will build up in the body, which can eventually cause cells to divide uncontrollably.

This study was an unusual approach to unpicking the genetic basis of diseases like cancer, but it has shown that people who have had their DNA sequenced can provide important information to help identify and understand the causes of a disease and then ultimately finding ways to fight it.