Panel screening of 56 other cancer predisposition genes did not reveal other germline pathogenic variants associated with melanoma (CDK4, BAP1, POT1), although pathogenic variants in TP53, CHEK2, and BRCA2 were present in three separate patients and some patients had variants of uncertain significance.
Here, we further assessed whether UM and CM are associated with BRCA1 or BRCA2 by assessing the presence, segregation and reported/predicted pathogenicity of rare germline mutations (variant allele frequency < 0.01) in families with multiple members affected by these cancers.
Men with a germline pathogenic BRCA1 or BRCA2 variant have increased risks for developing breast, pancreatic, prostate, and melanoma cancers, but little is known about how they understand and manage their cancer risks.
We also found a rare nonsense variant in the BRCA2 gene (rs11571833), previously associated with cancer susceptibility but not with melanoma, which showed weak association with melanoma susceptibility in the Swedish population.
By performing false-positive report probability corrections and stepwise Cox proportional hazards regression analyses, we identified significant associations between CM OS and four putatively functional SNPs: BRCA2rs10492396 (AG vs. GG: adjusted hazard ratio (adjHR)=1.85, 95% confidence interval (CI)=1.16-2.95, P=0.010), rs206118 (CC vs. TT+TC: adjHR=2.44, 95% CI=1.27-4.67, P=0.007), rs3752447 (CC vs. TT+TC: adjHR=2.10, 95% CI=1.38-3.18, P=0.0005), and FANCA rs62068372 (TT vs. CC+CT: adjHR=1.85, 95% CI=1.27-2.69, P=0.001).
The PALB2/BRCA2 protein interaction, as well as the increased melanoma risk observed in families harbouring BRCA2 mutations, makes PALB2 a candidate for melanoma susceptibility.
Such subsets of familial pancreatic cancer involve germline cationic trypsinogen or PRSS1 mutations (hereditary pancreatitis), BRCA2 mutations (usually in association with hereditary breast-ovarian cancer syndrome), CDKN2 mutations (familial atypical mole and multiple melanoma), or DNA repair gene mutations (e.g., ATM and PALB2, apart from those in BRCA2).
Mutations were identified in oncogenes and tumour suppressors previously linked to melanoma including BRAF, NRAS, KIT, PTEN and TP53, in cancer genes not previously linked to melanoma and in genes linked to DNA repair such as BRCA1 and BRCA2.
For melanoma susceptibility, investigations at germline level indicated that p16(CDKN2A) was exclusively mutated in 16/545 (2.9%) non-Sardinian patients, whereas BRCA2 germline mutations were observed in 4/91 (4.4%) patients from North Sardinia only.
In conclusion, we report an increased melanoma risk among carriers of the N991D change of the BRCA2 and no association of the CHEK2 changes with malignant melanoma.
We performed a genome-wide scan of two Danish pedigrees with multiple cases of OMM (N = 10) and CMM (N = 3) and other malignancies (with no germline mutations in CDKN2A, CDK4, BRCA1, and BRCA2) to identify melanoma susceptibility genes.
Moreover, carriers of mutations in the breast cancer predisposition gene, BRCA2, have an increased risk of melanoma while carriers of mutations in the melanoma susceptibility gene, CDKN2A, exhibit a higher than expected risk of breast cancer.
In this study we have investigated the presence of 7 types of cancer (ovary, male breast, pancreas, prostate, colon, stomach and melanoma) in first- and second-degree relatives of mutation-positive individuals in 440 families with a BRCA2 mutation.
The association of uveal melanoma with breast and ovarian cancer and the increased risk in BRCA2-linked families implicates germline BRCA2 mutations as the cause of a subset of uveal melanomas.
Germline mutations in BRCA2 have been shown to predispose to both breast and pancreatic cancer, germline mutations in p16 to melanoma and pancreatic cancer (the FAMMM syndrome), and genetic mutations in STK11/LKB1 to pancreatic cancer in patients with the Peutz-Jeghers Syndrome (PJS).
Tumours of the stomach and cervix, as well as melanoma and leukaemia/lymphoma also occur in these pedigrees but the numbers are too low to determine whether they may be significantly associated with BRCA2 carrier status.