When Spanish scientists came across the strange case of a woman who had suffered from 12 different types of tumors before the age of 36, they decided to dig a little deeper to find out why she had been infected. cancer.
The 36-year-old woman was treated for cancer for the first time at the age of two. At the age of 15, she was diagnosed with cervical cancer.
At the age of 20, the salivary gland tumor was surgically removed. A year later, I had another surgery to remove my low-grade sarcoma.
And while she was in her twenties and thirties, many different tumors were diagnosed.
In all, she had 12 tumours, including five malignancies.
With the permission of the woman and her family, an international team of researchers led by the Spanish National Center for Cancer Research took blood samples and used single-cell DNA sequencing to look at genetic mutations within thousands of individual cells.
The researchers discovered something strange. This woman had a unique mutation that made her more likely to develop cancer.
She had a mutation in both copies of the MAD1L1 gene, which is unheard of in humans.
The MAD1L1 gene is responsible for an essential piece of machinery that helps align chromosomes before cell division. MAD1L1 has previously been suspected to play a role in tumor suppression.
Mutations in the gene are unknown – in fact, members of the woman’s family carried one. But this is the first time that two copies of a gene have been found to carry this very change.
The double (or homozygous) MAD1L1 gene mutation is lethal to mouse embryosso it is a very surprising finding in humans.
In this woman, the cause of the mutation was impaired cell proliferation Create cells with different numbers of chromosomes. About 30-40% of blood cells have an abnormal number of chromosomes.
Humans usually have 23 pairs of chromosomes within the nucleus of every cell in our bodies.
chromosomes They are condensed packets of DNA that come in an “X” shape and form when a cell is about to undergo division or cell reproduction.
In each pair of chromosomes, one comes from the person’s mother and the other from the person’s father.
People with a rare condition called “various mosaic aneuploidy” (MVA) have different numbers of chromosomes in different cells, like a mosaic of different colored tiles. This condition could be caused by Several different genetic mutationsincluding those seen in a woman with 12 carcinomas.
People born with MVA mostly He suffers from developmental delay, microcephaly (where the baby’s head is smaller than normal), intellectual disability, and other birth defects. they often Predisposition to cancer.
In this case, the woman did not have intellectual disabilities and was living a relatively normal life (considering the number of rounds of cancer treatment she underwent).
“We still don’t understand how this person could have developed during the embryonic stage, and not all of these diseases can be overcome,” Says Marcos Malombres, a molecular biologist, co-author and chair of the Cell Division and Cancer Group at the Spanish National Center for Cancer Research, where this study was conducted.
And we know that a high degree of aneuploidy is associated with it worse results in cancer.
The study revealed that aneuploid people, like this woman in the case study, had an “enhanced immune response” that could “provide new opportunities for the clinical management of these patients,” according to the researchers. Say.
This paper was published in science progress.