In an era where genetics is reshaping our understanding of diseases, recent customer research publications offer invaluable insights, particularly in the realm of cancer. A study titled “Co-Occurrence of Germline Genomic Variants and Copy Number Variations in Hereditary Breast and Colorectal Cancer Patients” dives into a rare phenotype bridging hereditary colorectal and breast cancer syndromes, revealing the profound impact of genetic variants on cancer susceptibility. Parallelly, research on the “Prevalence and clinical implications of germline pathogenic variants in cancer predisposing genes in young patients across sarcoma subtypes” casts light on the mystifying domain of sarcomas, highlighting the significance of genetic predispositions in younger patients. As we journey through these Golden Helix VarSeq user research publications, the details of our DNA unravel, promising breakthroughs in cancer diagnostics and treatment.
Co-Occurrence of Germline Genomic Variants and Copy Number Variations in Hereditary Breast and Colorectal Cancer Patients
Hereditary Breast and Ovarian Cancer (HBOC) syndrome is an autosomal dominant disease associated with a high risk of developing breast, ovarian, and other malignancies. Lynch syndrome is caused by mutations in mismatch repair genes predisposing to colorectal and endometrial cancers, among others. A rare phenotype overlapping hereditary colorectal and breast cancer syndromes is poorly characterized. Three breast and colorectal cancer unrelated patients fulfilling clinical criteria for HBOC were tested by whole exome sequencing. A family history of colorectal cancer was reported in two patients (cases 2 and 3). Several variants and copy number variations were identified, which potentially contribute to the cancer risk or prognosis. All patients presented copy number imbalances encompassing PMS2 (two deletions and one duplication), a known gene involved in the DNA mismatch repair pathway. Two patients showed gains covering the POLE2 (cases 1 and 3), which is associated with DNA replication. Germline potentially damaging variants were found in PTCH1 (patient 3), MAT1A, and WRN (patient 2). Overall, concurrent genomic alterations were described that may increase the risk of cancer appearance in HBOC patients with breast and colorectal cancers.
Prevalence and clinical implications of germline pathogenic variants in cancer predisposing genes in young patients across sarcoma subtypes
Methods Germline DNA from 177 children, adolescents and young adults with soft tissue or bone sarcomas was tested using multigene panels with 113 or 126 cancer predisposing genes (CPGs) to describe the prevalence of germline pathogenic/likely pathogenic variants (GPVs). Subsequent testing of a subset of tumours for loss of heterozygosity (LOH) evaluation was performed to investigate the clinical and molecular significance of these variants.
Results GPVs were detected in 21.5% (38/177) of the patients (15.8% in children and 21.6% in adolescents and young adults), with dominant CPGs being altered in 15.2% overall. These variants were found in genes previously associated with the risk of developing sarcomas (TP53, RB1, NF1, EXT1/2) but also in genes where that risk is still emerging/limited (ERCC2, TSC2 and BRCA2) or unknown (PALB2, RAD50, FANCM and others). The detection rates of GPVs varied from 0% to 33% across sarcoma subtypes and GPV carriers were more likely to present more than one primary tumour than non-carriers (21.1%×6.5%; p=0.012). Loss of the wild-type allele was detected in 48% of tumours from GPV carriers, mostly in genes definitively associated with sarcoma risk.
Background Sarcomas are a rare and diverse group of cancers occurring mainly in young individuals for which an underlying germline genetic cause remains unclear in most cases.
Conclusion Our findings reveal that a high proportion of young patients with sarcomas presented a GPV in a CPG, underscoring the urgency of establishing appropriate genetic screening strategies for these individuals and their families.