A woman with a rare set of genetic mutations got cancer 5 times by the time she was 36

• A woman had cancer 5 times before she turned 36, the first time when she was two.
• A study found she has never-before-seen mutations that were thought to be impossible to survive.

A woman who was diagnosed with cancer 5 times in different parts of her body by age 36 has a set of mutations never before spotted in medicine, a study reported.

The findings, published in the peer-reviewed journal Science Advances on November 2, show the importance of getting genetic testing in families that have a few tumors, as study author said.

In total the woman, who wasn't named, developed 12 different tumors, five of which were cancerous and seven of which were benign.

The woman had her first cancer at age two, a tumor in which was treated with radiotherapy and chemotherapy.

She developed new tumors every few years after that, including in the bones, cervix, breast, skin, and thyroid gland, some of which required surgery.

Five of those tumors turned into cancer, per the study. But these mysteriously healed much quicker than expected, Marcos Malumbres, head of the Cell Division and Cancer Group at the Spanish National Cancer Research Centre, told Insider.

"There are not many cases with this amount of tumors," said Malumbres. While some patients develop multiple tumors, they usually come from a single cause — while the woman in the study developed 12 independent ones.

"These are tumors that come from different cells in different tissues at different ages," he noted,

An impossible mutation

Humans have two copies of most genes, one on each chromosome. This is a good safeguarding mechanism because if one copy goes awry, the other might be healthy, so the body may be able to compensate.

The patient in this case had mutations in both copies of a gene called MAD1L1. This gene is involved in splitting copies of the chromosomes evenly when the body's cells divide.

That means that a lot of cells in this patient's body didn't always have the right number of chromosomes, causing havoc.

Researchers thought these mutations could not be survived

MAD1L1 is so central to the way the body works that scientists previously thought that it was impossible to survive with this set of mutations. Mice with these mutations would die as embryos, a previous study found.

"We still don't understand how this individual could have developed during the embryonic stage, nor could have overcome all these pathologies," Malumbres said in an accompanying press release.

However, the woman seems to be living pretty well with her condition.

"Most of the tumors were when she was very young, so now she's quite stable, she has a normal lifestyle. She's working, she's now living on her own," he said.

"So there is nothing very dramatic about her, apart from very frequent visits to the hospital," he said.

That this woman survived her five cancers really intrigued the scientists.

It is possible that faced with so many cells with an unusual number of chromosomes, the body boosted a "defensive response" that helps the tumors disappear, Malumbres said.

This means the immune system might have a secret tool to spot cells with unusual chromosome numbers that had only before been spotted in mice and in Petri dishes, Malumbres said.

"I think it's the first case where a patient is reported having that," he said.

Genetic testing is key

The information about the patient's mutation may also be useful to her family to understand their own medical issues, Malumbres said.

The patient's sister, aunt, and grandmother all have had spontaneous abortions, Malumbres said. All of them likely carry one copy of the mutation.

"I think it's very important to realize that is something that is in their DNA and will be transmitted to their children," he said.

"For me, the most important conclusion from that is you don't need to wait until you have 12 tumors to be analyzed at a genetic level," he said.