No constitutional p53 mutations were detected in any of these patients, implying that outside the clinical spectrum of LFS, constitutional p53 mutations are rare in patients with lymphomas.
This is, to our knowledge, the largest single report of diagnostic testing for germline p53 mutations, yielding practical mutation prevalence tables and suggesting clinical utility of classic LFS and Chompret criteria for identifying a subset of cancer-prone families with p53 germline mutations, with important implications for diagnosis and management.
Five immortal cell lines derived from a Li-Fraumeni syndrome patient (MDAH 087) with a germline mutant p53 allele were characterized with respect to telomere length and genomic instability.
To test our hypothesis that changes in gene expression beyond p53 per se are contributing to the development of tumors, we compared gene expression in non-cancerous skin fibroblasts of LFS-affected (p53 heterozygous) vs. non-affected (p53 wild-type homozygous) family members.
In contrast to the accepted concept that p53 homozygous mutant mice do not accumulate mutant p53 in normal cells, our study on a mutant p53 mouse model of Li-Fraumeni syndrome harbouring the hot-spot p53R172H mutation described an elevated level of mutant p53 in non-cancerous mouse tissues.
Most of the genes listed are responsible for various well-defined cancer syndromes, such as CDKN2A (familial atypical mole-multiple melanoma, FAMMM), the mismatch repair genes (Lynch Syndrome), TP53 (Li-Fraumeni syndrome), APC (familial adenomatous polyposis), and BRCA2 (breast-ovarian familial cancer), where PC is part of the cancer spectrum of the disease.
It is believed that the loss of p53 wild type function contributes to immortalization of these LFS fibroblasts, but it is not clear if this is sufficient.
These results suggest germline p53 mutations to possibly be responsible for a subset of young adult patient with multiple malignant tumors, even those not meeting the clinical criteria for LFS or LFL.
A significant prevalence of homozygous MDM2 SNP309 G in the LFS Suggestive group (p < 0.0005) confirms its contribute to cancer susceptibility, also highlighted in LFSTP53 positive families.
We report two cases of non-smoker patients diagnosed with EGFR-mutated lung adenocarcinoma and bearing germinal TP53 gene mutation, also known as Li-Fraumeni syndrome (LFS).
Li-Fraumeni syndrome (LFS) is an autosomal dominantly inherited disorder characterized by a strikingly increased risk of early-onset breast cancer, sarcomas, brain tumors and other neoplasms in individuals harboring germline TP53 mutations.
We report here a family with some of the characteristics of Li-Fraumeni syndrome (Li-Fraumeni-like) in which there is a 2 base pair deletion within exon 6 of TP53 in two affected individuals.
Analysis revealed a nonsense variant of TP53 which has been previously reported in families with sarcomas and other typical Li Fraumeni syndrome-associated cancers but never in a familial leukemia kindred.
Germline mutations in the tumor suppressor gene TP53 occur in the majority of families with Li-Fraumeni syndrome, who are at an increased risk for a wide spectrum of early onset cancers.
In addition to these features of sporadic cancers, some individuals inherit mutant forms of p53 and consequently suffer from Li-Fraumeni syndrome, showing genetic predisposition to certain malignancies.
A p53 germline point mutation was identified in one family with some findings of Li-Fraumeni syndrome, and a hemizygous germline deletion of the p16(INK4A)/p14(ARF) tumor suppressor region was demonstrated by FISH in a family with history of both astrocytoma and melanoma.