ALi-Fraumeni syndrome It is an inherited condition that leads to a predisposition to the development of cancer. With an autosomal dominant inheritance pattern, this syndrome is related to different mutations in the TP53 gene, a gene that works to prevent tumors from forming in our body, being called by some authors the “guardian of the genome” gene.
Between the tumors most frequently associated with the syndrome are breast cancers, soft tissue sarcomas, bone sarcomas, central nervous system tumors, adrenocortical tumors and leukemias.
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Overview of Li-Fraumeni syndrome
Li-Fraumeni syndrome is a rare, inherited condition that predisposes to cancer.
It is a syndrome with an autosomal dominant inheritance pattern.
The syndrome is associated with the occurrence of different types of cancer, such as sarcomas, breast cancer, adrenocortical and central nervous system.
Brazil concentrates a large number of people with the syndrome due to the occurrence of a specific mutation.
What is Li-Fraumeni syndrome?
Li-Fraumeni syndrome, described in 1969 by Frederick Li and Joseph Fraumeni, is ahereditary condition and rare which leads to a predisposition to the development of cancer. It is associated with cases of tumor development in childhood and youth.
She relates to mutations in the TP53 gene and it is an autosomal dominant disease. O gene TP53, called by some authors “guardian of the genome”, has several functions in the cell cycle and key role in preventing cells that have errors proliferate and give rise to tumors. Mutations in this gene affect this capacity, favoring the development of cancers.
One of the mutations of the TP53 gene occurs only in Brazil and is known as R337H. It stands out for being a mutation that predisposes to the risk of developing cancer, but this is lower than that observed in people who have other mutations. According to the A.C.Camargo Cancer Center, this characteristic leads the scientific community to call it Li-Fraumeni-Like. In a simplified way, we can say that the Li-Fraumeni- Like leads to the development of a milder phenotype.
Most common types of tumors in Li-Fraumeni syndrome
Among the tumors most frequently found in Li-Fraumeni syndrome and Li-Fraumeni- Like are breast cancers, soft tissue sarcomas, bone sarcomas, tumors in the central nervous system, adrenocortical tumors and leukemias.
Classic criteria for suspecting Li-Fraumeni syndrome
The diagnosis of Li-Fraumeni syndrome is not an easy task, so a detailed study of the family of a suspected case should be carried out. Some situations may raise the suspicion of the existence of the syndrome and, from there, an investigation must be carried out.
The following are considered classic criteria for suspecting Li-Fraumeni syndrome:
person with sarcoma diagnosed before age 45,
person who has a 1st degree relative diagnosed before the age of 45 with any type of cancer and another 1st degree relative or 2nd degree who was diagnosed with sarcoma at any age or any type of cancer before age 45 age.
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Li-Fraumeni Syndrome in Brazil
Li-Fraumeni syndrome occurs more frequently in Brazil than in any other part of the world. As noted earlier, in Brazil a mutation in the TP53 gene is observed that is different from those observed in other regions of the world. This mutation, in general, reduces the chance of developing cancer when compared to people who have the syndrome in other parts of the world.
In addition Brazilian mutation causes cancer not to appear very early and, with that, increases the chance of the individual having children and passing on his mutant gene to the next generations, increasing the prevalence of the syndrome in Brazil. According to a BBC report, “In the rest of the world, genetic mutations in TP53 also tend to cause cancer earlier—in 50% of cases before the age of 30. In the Brazilian case, this index is 30%”.|1|
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|1| Available material here.
By Vanessa Sardinha dos Santos
Biology teacher
Source: Brazil School - https://brasilescola.uol.com.br/doencas/sindrome-de-li-fraumeni.htm