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Germline mutations in the major melanoma susceptibility gene CDKN2A explain genetic predisposition in only 10–40% of melanoma‐prone families. In our study we comprehensively characterized 488 melanoma cases from 451 non‐CDKN2A/CDK4 families for mutations in 30 established and candidate melanoma susceptibility genes using a custom‐designed targeted gene panel approach. We identified (likely) pathogenic variants in established melanoma susceptibility genes in 18 families (n = 3 BAP1, n = 15 MITF p.E318K; diagnostic yield 4.0%). Among the three identified BAP1‐families, there were no reported diagnoses of uveal melanoma or malignant mesothelioma. We additionally identified two potentially deleterious missense variants in the telomere maintenance genes ACD and TERF2IP, but none in the POT1 gene. MC1R risk variants were strongly enriched in our familial melanoma cohort compared to healthy controls (R variants: OR 3.67, 95% CI 2.88–4.68, p, What's new? Germline mutations in CDKN2A are major contributors to familial melanoma. These mutations, however, are responsible for only 10 to 40 percent of genetic susceptibility in melanoma‐prone families. In this study, 30 established and candidate melanoma susceptibility genes were investigated for associations with the disease in patients from 451 non‐CDKN2A/CDK4 melanoma families. From the candidate gene panel, (likely) pathogenic variants in BAP1 and MITF were identified in several families, and potentially deleterious variants were identified in the shelterin complex genes ACD and TERF2IP. These genes appear to play a significant role in familial melanoma predisposition and are therefore promising candidates for incorporation into comprehensive genetic tests.

BackgroundSeveral factors have been reported that influence the probability of a germline CDKN2A mutation in a melanoma family. Our goal was to create a scoring system to estimate this probability, based on a set of clinical features present in the patient and his or her family.MethodsFive clinical features and their association with CDKN2A mutations were investigated in a training cohort of 1227 Dutch melanoma families (13.7% with CDKN2A mutation) using multivariate logistic regression. Predefined features included number of family members with melanoma and with multiple primary melanomas, median age at diagnosis and presence of pancreatic cancer or upper airway cancer in a family member. Based on these five features, a scoring system (CDKN2A Mutation(CM)-Score) was developed and subsequently validated in a combined Swedish and Dutch familial melanoma cohort (n=421 families; 9.0% with CDKN2A mutation).ResultsAll five features were significantly associated (pCDKN2A mutation. At a CM-Score of 16 out of 49 possible points, the threshold of 10% mutation probability is approximated (9.9%; 95% CI 9.8 to 10.1). This probability further increased to >90% for families with ≥36 points. A CM-Score under 16 points was associated with a low mutation probability (≤4%). CM-Score performed well in both the training cohort (area under the curve (AUC) 0.89; 95% CI 0.86 to 0.92) and the external validation cohort (AUC 0.94; 95% CI 0.90 to 0.98).ConclusionWe developed a practical scoring system to predict CDKN2A mutation status among melanoma-prone families. We suggest that CDKN2A analysis should be recommended to families with a CM-Score of ≥16 points.

Most genetic susceptibility to cutaneous melanoma remains to be discovered. Meta-analysis genome-wide association study (GWAS) of 36,760 cases of melanoma (67% newly genotyped) and 375,188 controls identified 54 significant (P < 5 × 10−8) loci with 68 independent single nucleotide polymorphisms. Analysis of risk estimates across geographical regions and host factors suggests the acral melanoma subtype is uniquely unrelated to pigmentation. Combining this meta-analysis with GWAS of nevus count and hair color, and transcriptome association approaches, uncovered 31 potential secondary loci for a total of 85 cutaneous melanoma susceptibility loci. These findings provide insights into cutaneous melanoma genetic architecture, reinforcing the importance of nevogenesis, pigmentation and telomere maintenance, together with identifying potential new pathways for cutaneous melanoma pathogenesis. © 2020, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.

Background: Germline variants in the melanocortin 1 receptor gene (MC1R) might increase the risk of childhood and adolescent melanoma, but a clear conclusion is challenging because of the low number of studies and cases. We assessed the association of MC1R variants with childhood and adolescent melanoma in a large study comparing the prevalence of MC1R variants in child or adolescent patients with melanoma to that in adult patients with melanoma and in healthy adult controls. Methods: In this retrospective pooled analysis, we used the M-SKIP Project, the Italian Melanoma Intergroup, and other European groups (with participants from Australia, Canada, France, Greece, Italy, the Netherlands, Serbia, Spain, Sweden, Turkey, and the USA) to assemble an international multicentre cohort. We gathered phenotypic and genetic data from children or adolescents diagnosed with sporadic single-primary cutaneous melanoma at age 20 years or younger, adult patients with sporadic single-primary cutaneous melanoma diagnosed at age 35 years or older, and healthy adult individuals as controls. We calculated odds ratios (ORs) for childhood and adolescent melanoma associated with MC1R variants by multivariable logistic regression. Subgroup analysis was done for children aged 18 or younger and 14 years or younger. Findings: We analysed data from 233 young patients, 932 adult patients, and 932 healthy adult controls. Children and adolescents had higher odds of carrying MC1R r variants than did adult patients (OR 1·54, 95% CI 1·02–2·33), including when analysis was restricted to patients aged 18 years or younger (1·80, 1·06–3·07). All investigated variants, except Arg160Trp, tended, to varying degrees, to have higher frequencies in young patients than in adult patients, with significantly higher frequencies found for Val60Leu (OR 1·60, 95% CI 1·05–2·44; p=0·04) and Asp294His (2·15, 1·05–4·40; p=0·04). Compared with those of healthy controls, young patients with melanoma had significantly higher frequencies of any MC1R variants. Interpretation: Our pooled analysis of MC1R genetic data of young patients with melanoma showed that MC1R r variants were more prevalent in childhood and adolescent melanoma than in adult melanoma, especially in patients aged 18 years or younger. Our findings support the role of MC1R in childhood and adolescent melanoma susceptibility, with a potential clinical relevance for developing early melanoma detection and preventive strategies. Funding: SPD-Pilot/Project-Award-2015; AIRC-MFAG-11831. © 2019 Elsevier Ltd

Germline mutations in CDKN2A are frequently identified among melanoma kindreds and are associated with increased atypical nevus counts. However, a clear relationship between pathogenic CDKN2A mutation carriage and other nevus phenotypes including counts of common acquired nevi has not yet been established. Using data from GenoMEL, we investigated the relationships between CDKN2A mutation carriage and 2-mm, 5-mm, and atypical nevus counts among blood-related members of melanoma families. Compared with individuals without a pathogenic mutation, those who carried one had an overall higher prevalence of atypical (odds ratio = 1.64; 95% confidence interval = 1.18–2.28) nevi but not 2-mm nevi (odds ratio = 1.06; 95% confidence interval = 0.92–1.21) or 5-mm nevi (odds ratio = 1.26; 95% confidence interval = 0.94–1.70). Stratification by case status showed more pronounced positive associations among non-case family members, who were nearly three times (odds ratio = 2.91; 95% confidence interval = 1.75–4.82) as likely to exhibit nevus counts at or above the median in all three nevus categories simultaneously when harboring a pathogenic mutation (vs. not harboring one). Our results support the hypothesis that unidentified nevogenic genes are co-inherited with CDKN2A and may influence carcinogenesis.

Germline CDKN2A mutations occur in 40 % of 3-or-more case melanoma families while mutations of CDK4, BAP1, and genes involved in telomere function (ACD, TERF2IP, POT1), have also been implicated in melanomagenesis. Mutation of the promoter of the telomerase reverse transcriptase (TERT) gene (c.-57 T>G variant) has been reported in one family. We tested for the TERT promoter variant in 675 multicase families wild-type for the known high penetrance familial melanoma genes, 1863 UK population-based melanoma cases and 529 controls. Germline lymphocyte telomere length was estimated in carriers. The c.-57 T>G TERT promoter variant was identified in one 7-case family with multiple primaries and early age of onset (earliest, 15 years) but not among population cases or controls. One family member had multiple primary melanomas, basal cell carcinomas and a bladder tumour. The blood leukocyte telomere length of a carrier was similar to wild-type cases. We provide evidence confirming that a rare promoter variant of TERT (c.-57 T>G) is associated with high penetrance, early onset melanoma and potentially other cancers, and explains

The MC1R gene is a key regulator of skin pigmentation. We aimed to evaluate the association between MC1R variants and the risk of sporadic cutaneous melanoma (CM) within the M-SKIP project, an international pooled-analysis on MC1R, skin cancer and phenotypic characteristics. Data included 5,160 cases and 12,119 controls from 17 studies. We calculated a summary odds ratio (SOR) for the association of each of the nine most studied MC1R variants and of variants combined with CM by using random-effects models. Stratified analysis by phenotypic characteristics were also performed. Melanoma risk increased with presence of any of the main MC1R variants: the SOR for each variant ranged from 1.47 (95%CI: 1.17-1.84) for V60L to 2.74 (1.53-4.89) for D84E. Carriers of any MC1R variant had a 66% higher risk of developing melanoma compared with wildtype subjects (SOR; 95%CI: 1.66; 1.41-1.96) and the risk attributable to MC1R variants was 28%. When taking into account phenotypic characteristics, we found that MC1R-associated melanoma risk increased only for darker-pigmented Caucasians: SOR (95%CI) was 3.14 (2.06-4.80) for subjects with no freckles, no red hair and skin Type III/IV. Our study documents the important role of all the main MC1R variants in sporadic CM and suggests that they have a direct effect on melanoma risk, independently on the phenotypic characteristics of carriers. This is of particular importance for assessing preventive strategies, which may be directed to darker-pigmented Caucasians with MC1R variants as well as to lightly pigmented, fairskinned subjects. © 2014 UICC.

Background: For complex diseases like cancer, pooled-analysis of individual data represents a powerful tool to investigate the joint contribution of genetic, phenotypic and environmental factors to the development of a disease. Pooled-analysis of epidemiological studies has many advantages over meta-analysis, and preliminary results may be obtained faster and with lower costs than with prospective consortia. Design and methods. Based on our experience with the study design of the Melanocortin-1 receptor (MC1R) gene, SKin cancer and Phenotypic characteristics (M-SKIP) project, we describe the most important steps in planning and conducting a pooled-analysis of genetic epidemiological studies. We then present the statistical analysis plan that we are going to apply, giving particular attention to methods of analysis recently proposed to account for between-study heterogeneity and to explore the joint contribution of genetic, phenotypic and environmental factors in the development of a disease. Within the M-SKIP project, data on 10,959 skin cancer cases and 14,785 controls from 31 international investigators were checked for quality and recoded for standardization. We first proposed to fit the aggregated data with random-effects logistic regression models. However, for the M-SKIP project, a two-stage analysis will be preferred to overcome the problem regarding the availability of different study covariates. The joint contribution of MC1R variants and phenotypic characteristics to skin cancer development will be studied via logic regression modeling. Discussion. Methodological guidelines to correctly design and conduct pooled-analyses are needed to facilitate application of such methods, thus providing a better summary of the actual findings on specific fields. © 2012 Raimondi et al.

We report a genome-wide association study of melanoma conducted by the GenoMEL consortium based on 317K tagging SNPs for 1,650 selected cases and 4,336 controls, with replication in an additional two cohorts (1,149 selected cases and 964 controls from GenoMEL, and a population-based case-control study in Leeds of 1,163 cases and 903 controls). The genome-wide screen identified five loci with genotyped or imputed SNPs reaching P < 5 times 10-7. Three of these loci were replicated: 16q24 encompassing MC1R (combined P = 2.54 times 10-27 for rs258322), 11q14-q21 encompassing TYR (P = 2.41 times 10-14 for rs1393350) and 9p21 adjacent to MTAP and flanking CDKN2A (P = 4.03 times 10-7 for rs7023329). MC1R and TYR are associated with pigmentation, freckling and cutaneous sun sensitivity, well-recognized melanoma risk factors. Common variants within the 9p21 locus have not previously been associated with melanoma. Despite wide variation in allele frequency, these genetic variants show notable homogeneity of effect across populations of European ancestry living at different latitudes and show independent association to disease risk.

Melanoma is the most aggressive and lethal type of skin cancer since it has the ability to spread to other organs in the body making it harder to control the disease.In this thesis, we aim to explore the degree to which epigenetics play a role in melanoma, namely, inherited and acquired epigenetic alterations in melanoma susceptibility and development.

The studies in this thesis explored several aspects of genetic dependencies in the development of familial and sporadic melanoma. CDKN2A is the most common high-penetrance susceptibility gene responsible for up to 40% of melanoma families worldwide. Interestingly, more than half of germline variation in familial predisposition to melanoma remains to be determined. To identify novel high-penetrance melanoma susceptibility genes we applied Whole Exome Sequencing (WES) and co-segregation analysis in a Dutch melanoma family. We identified NEK11 as a candidate high-penetrance melanoma susceptibility gene and performed functional characterization in cancer cell lines to show loss-of-function (chapter 2). Our additional focus of investigation was a specific cohort of familial melanoma patients carrying a CDKN2A founder mutation, a 19-bp deletion known as the p16-Leiden mutation. Due to the variability in occurrence of pancreatic cancer (PC) and melanoma within familial melanoma families, we sought to examine genetic modifiers predicting the risk of PC and melanoma (chapter 3). In this specific cohort of familial melanoma patients, the timing of CDKN2A wild-type allele loss in melanoma development is unknown. We have applied a customized SNP-based digital PCR (dPCR) methodology to precisely quantify CDKN2A allelic imbalance depicting loss-of-heterozygosity (LOH) and attempted to deduce the order of genetic events based on absolute quantification of mutations and losses (CDKN2A LOH, BRAFV600E, TERT promoter, chromosome 9q LOH) (chapter 4). Finally, in addition to high-penetrance genes in familial melanoma, there are genes that are important fitness factors for cancer cell growth and may provide insight into the biology and progression of sporadic melanoma. The application of screening technologies has been successful in identifying genetic dependencies that could possibly be implemented as therapeutic targets in cancer. We have therefore analyzed Clustered Regular Interspaced Short Palindromic Repeats (CRISPR-Cas9) screening data to identify fitness genes in melanoma and used in-vitro systems to validate our findings (chapter 5). Combined, we hope to have uncovered novel genetic dependencies that could be used in the targeted treatment of sporadic as well as familial melanoma.

The Human Genome Epidemiology Network (HuGENet) recently launched a global network of consortia working on human genome epidemiology. This Network of Investigator Networks aims to create a resource to share information, offer methodologic support, generate inclusive overviews of studies conducted in specific fields, and to facilitate rapid confirmation of findings. In October 2005, HuGENet brought together representatives from established and emerging networks in order to share their experiences at a workshop in Cambridge, United Kingdom. In advance of the meeting, a qualitative questionnaire was distributed to workshop participants. The questionnaire elicited information on experiences and practices in building and maintaining consortia. This chapter reports on the numerous challenges and their possible solutions as identified by the workshop participants, as well as new opportunities offered by the network approach to genetic and genomic epidemiology.

The results obtained in this thesis suggest that the most explicit differences between normal and atypical melanocytes are subtle changes in pigment biosynthesis and the functioning of the antioxidant system. Impairment of the antioxidant system and increased levels of pheomelanin result in increased levels of oxidative stress. It is anticipated that these increased levels of oxidative stress contribute to early melanoma development by inducing DNA mutations, but additional studies are required to prove this hypothesis.