Deadly cancer secret revealed

Main Category: Melanoma / Skin Cancer
Article Date: 02 Aug 2003 - 0:00 PDT


Scientists have found the location of an important new gene which pre-disposes people to skin cancer.

A team from Cancer Research UK are part of the international team close to isolating the gene, which they have found to sit on a tiny part of chromosome 1 - one of the bundles of DNA containing our genes.

Inheriting a faulty version of the gene is thought to give people a much higher than average chance of developing malignant melanoma - the most dangerous form of skin cancer - and may be responsible for up to a third of inherited cases.

The scientists believe the study provides a valuable insight into the way in which melanoma develops.

In the future, they hope it will help doctors to identify, monitor and advise those more susceptible to the disease to help them reduce their risk.

The most important cause of melanoma is exposure to the sun, but scientists think that, in around 10% of cases, inherited genes play a role.

Important genes

Past research has already identified two genes - CDKN2A and CDK4 - which increase the risk of melanoma when inherited in a faulty form.

But scientists know other genes are likely to exist because CDKN2A and CDK4 only account for around 30% of inherited cases.

Researcher Dr Julia Newton-Bishop said: 'Sun exposure causes damage to the skin's DNA and accumulation of this damage can lead to cancer.

'Some people may inherit an increased susceptibility to melanoma and for these individuals avoiding the sun's rays becomes even more important.'

The team searched for new risk genes by analysing genetic data from around 80 Australian, European and American families, with three or more cases of melanoma that weren't caused by a faulty version of either the CDKN2A or CDK4 genes.

They found that a number of the families had the particular stretch of DNA on chromosome 1 in common and had inherited it in a pattern that matched the inheritance of melanoma.

Early signs

The team looked specifically at families where individuals had developed melanoma at an early age - a sign that the disease is inherited.

They found those families with the earliest age of onset were most likely to carry this particular region on chromosome 1.

Professor Tim Bishop, from Cancer Research UK's Clinical Centre in Leeds, said: 'We've narrowed down the location of the melanoma gene to a tiny piece of DNA, which puts us one step away from finding the gene itself.

'We believe the gene we are close to finding is one of the major risk genes for melanoma and could be responsible for around 30% of inherited cases.

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