The CFTR Gene Germline Heterozygous Pathogenic Variants in Russian Patients with Malignant Neoplasms and Healthy Carriers: 11,800 WGS Results

Assessing germline TP53 mutations in cancer patients: insights into Li-Fraumeni syndrome and genetic testing guidelines

BACKGROUND

Germline TP53 gene variants are intricately linked to Li-Fraumeni syndrome, a rare and aggressive hereditary cancer syndrome. This study investigated the frequency and spectrum of TP53 pathogenic variants associated with Li-Fraumeni syndrome in a large cohort of mainly breast cancer patients from Russia.

METHODS

The study analyzed 3,455 genomic DNA samples from cancer patients using next-generation sequencing panels and whole-genome sequencing. Clinically significant TP53 variants were identified and validated using Sanger sequencing. The clinical and family history characteristics of patients with TP53 variants were analyzed.

RESULTS

The analysis identified 13 (0.4%) individuals with clinically significant germline TP53 variants, all of whom were females with either unilateral breast cancer or breast cancer as part of multiple primary malignant neoplasms. The average age of breast cancer manifestation was 39.9 years, with a median of 36 years. Only 38.5% of the TP53 mutation carriers met the modified Chompret criteria for TP53 testing.

CONCLUSIONS

The findings underscore the necessity of thorough phenotype and family history analysis in genetic counseling to effectively diagnose LFS, and emphasize the importance of identifying TP53 variant carriers for developing treatment strategies, prognosis, and monitoring, as well as for identifying high-risk family members. The study also highlights that the current guidelines fail to identify over half of the TP53 mutation carriers, suggesting the need for a more comprehensive approach to genetic testing in suspected hereditary cancer cases.

New RPS20 gene variant in colorectal cancer diagnosis: insight from a large series of patients

Germline pathogenic variants of the RPS20 (ribosomal protein S20) gene are suspected to be involved in the predisposition to familial colorectal cancer (CRC) with no DNA mismatch repair deficiency. RPS20 pathogenic variants are very rare with only five reported cases in the literature. We report in this work the retrospective germline analysis of RPS20 for 1035 consecutive patients with a personal and/or familial history suggestive of hereditary predisposition to CRC. Within this series, a pathogenic variant in known CRC genes was found in 15% of cases and we describe one RPS20 loss-of-function variant (NM_001146227.1:c.115_116del, p.(Leu39Aspfs*33)). This frameshift is the first reported de novo variant in CRC, it was identified in in a female patient diagnosed with rectal cancer at the age of 35, 11 adenomatous polyps in 5 years and breast cancer at the age of 43. RPS20 has an intriguing role in oncogenesis, acting as an oncogene or tumour suppressor depending on the context, and is also involved in Diamond-Blackfan anemia via gain of function or dominant negative variants. This is therefore a complex gene for genetic counselling and, given the rarity of RPS20 pathogenic variants, we emphasise the need to collect data to clarify the phenotypic spectrum of RPS20-associated cancers and thus improve management.

CDKN2A Gene Mutations: Implications for Hereditary Cancer Syndromes

Malignant neoplasms, including pancreatic cancer and melanoma, are major global health challenges. This study investigates melanoma pancreatic syndrome, a rare hereditary tumor syndrome associated with CDKN2A gene mutations. CDKN2A mutations contribute to a lifetime risk of melanoma ranging from 28% to 67%. This study reports the clinical features of six individuals with CDKN2A mutations and identifies recurrent alterations such as c.307_308del, c.159G>C and c.71G>C. It highlights the need for CDKN2A mutation testing in suspected cases of familial atypical multiple mole melanoma. Clinically significant variants show associations with melanoma and pancreatic cancer. The challenges of treating individuals with CDKN2A mutations are discussed, and the lack of specific targeted therapies is highlighted. Preclinical studies suggest a potential benefit of CDK4/6 inhibitors, although clinical trials show mixed results. This study underscores the importance of continued research into improved diagnostic and therapeutic strategies to address the complexities of hereditary cancer syndromes.