Jackie Corlett has already lost three siblings, who were all diagnosed in their 30s, to various forms of the disease.

Research into their deaths has revealed the family carry a faulty gene known as Li Fraumeni Syndrome (LFS), which often greatly increases the risk of cancer.

Mrs Corlett managed to track down relatives from her mother's side who have been checked and do not carry the gene.

Now Mrs Corlett believes the faulty gene could come from her father's side of the family, who come from Boldon Colliery.

Forrest Andrew was the youngest of 10 children of John and Ann Andrews.

The former Coldstream Guards Lance Corporal took wife Margaret from their Boldon Colliery home to London, when he was posted in the south.

He died of cancer in 1974.

His family has been blighted by the faulty gene, which has led to the death of two of Mrs Corlett's brothers and one of sister.

Another brother and sister are currently fighting cancer while Mrs Corlett and a remaining brother are carriers of the gene. So far they have been free from cancer.

Less than 400 families in the world have been diagnosed with LFS, and doctors at the Royal Marsden Hospital in London are currently carrying out research into the syndrome.

Now Mrs Corlett is trying to trace any family in South Tyneside and urging them to get checked.

Mrs Corlett said: "We have had my mam's history done and we can't find anything which links the genetic fault to her side of the family.

"With this gene people are diagnosed with cancer pretty young, mainly in their 30s, and we could have relatives who are suffering the same genetic problems as us and not know why.

"The gene is passed on to generations and our children are being checked on a regular basis as it its picked up quite early the cancer could be prevented."

Anyone who may be able to help Mrs Corlett find her father's relatives is asked to e-mail arfurskufcake@sky.com or write to Jackie Corlett, 77 Coleridge Crescent, Goring by Sea, West Sussex, BN12 6LU.