Project description:The main genetic factors for familial melanoma remain unknown in more than 75% of families. CDKN2A is mutated in around 20% of melanoma-prone families. Other high-risk melanoma susceptibility genes explain less than 3% of families studied to date. We performed the first genome-wide linkage analysis in CDKN2A-negative Spanish melanoma-prone families to identify novel melanoma susceptibility loci. We included 68 individuals from 2, 3 and 6 families with 2, 3 and at least 4 melanoma cases. We detected a locus with significant linkage evidence at 11q14.1-q14.3, with a maximum het-TLOD of 3.449 (rs12285365:A>G), using evidence from multiple pedigrees. The genes contained by the subregion with the strongest linkage evidence were: DLG2, PRSS23, FZD4 and TMEM135. We also detected several regions with suggestive linkage evidence (TLOD>1.9) (1q, 6p, 7p, 11q, 12p, 13q) including the region previously detected in melanoma-prone families from Sweden at 3q29. The family specific analysis revealed three loci with suggestive linkage evidence for family #1: 1q31.1-q32.1 (max. TLOD 2.447), 6p24.3-p22.3 (max. TLOD 2.409) and 11q13.3-q21 (max. TLOD 2.654). Future next generation sequencing studies of these regions may allow the identification of new melanoma susceptibility genetic factors. Overall design: The study included 29 melanoma cases and 39 non-affected individuals belonging to 11 Spanish melanoma prone families. Genome-wide genotyping was performed using the HumanOmni2.5 SNP array platform (Illumina).
Project description:The main genetic factors for familial melanoma remain unknown in more than 75% of families. CDKN2A is mutated in around 20% of melanoma-prone families. Other high-risk melanoma susceptibility genes explain less than 3% of families studied to date. We performed the first genome-wide linkage analysis in CDKN2A-negative Spanish melanoma-prone families to identify novel melanoma susceptibility loci. We included 68 individuals from 2, 3 and 6 families with 2, 3 and at least 4 melanoma cases. We detected a locus with significant linkage evidence at 11q14.1-q14.3, with a maximum het-TLOD of 3.449 (rs12285365:A>G), using evidence from multiple pedigrees. The genes contained by the subregion with the strongest linkage evidence were: DLG2, PRSS23, FZD4 and TMEM135. We also detected several regions with suggestive linkage evidence (TLOD>1.9) (1q, 6p, 7p, 11q, 12p, 13q) including the region previously detected in melanoma-prone families from Sweden at 3q29. The family specific analysis revealed three loci with suggestive linkage evidence for family #1: 1q31.1-q32.1 (max. TLOD 2.447), 6p24.3-p22.3 (max. TLOD 2.409) and 11q13.3-q21 (max. TLOD 2.654). Future next generation sequencing studies of these regions may allow the identification of new melanoma susceptibility genetic factors. Overall design: The study included 29 melanoma cases and 39 non-affected individuals belonging to 11 Spanish melanoma prone families. Genome-wide genotyping was performed using the HumanOmni2.5 SNP array platform (Illumina).
Project description:The main genetic factors for familial melanoma remain unknown in >75% of families. CDKN2A is mutated in around 20% of melanoma-prone families. Other high-risk melanoma susceptibility genes explain <3% of families studied to date. We performed the first genome-wide linkage analysis in CDKN2A-negative Spanish melanoma-prone families to identify novel melanoma susceptibility loci. We included 68 individuals from 2, 3, and 6 families with 2, 3, and at least 4 melanoma cases. We detected a locus with significant linkage evidence at 11q14.1-q14.3, with a maximum het-TLOD of 3.449 (rs12285365:A>G), using evidence from multiple pedigrees. The genes contained by the subregion with the strongest linkage evidence were: DLG2, PRSS23, FZD4, and TMEM135. We also detected several regions with suggestive linkage evidence (TLOD >1.9) (1q, 6p, 7p, 11q, 12p, 13q) including the region previously detected in melanoma-prone families from Sweden at 3q29. The family-specific analysis revealed three loci with suggestive linkage evidence for family #1: 1q31.1-q32.1 (max. TLOD 2.447), 6p24.3-p22.3 (max. TLOD 2.409), and 11q13.3-q21 (max. TLOD 2.654). Future next-generation sequencing studies of these regions may allow the identification of new melanoma susceptibility genetic factors.
Project description:BACKGROUND:In the United States, only approximately 0.4% of all melanomas are diagnosed in patients aged <20 years. To the authors' knowledge, melanoma in pediatric members of melanoma-prone families has not been fully investigated to date. The objective of the current study was to evaluate pediatric patients with melanoma with extensive follow-up in melanoma-prone families with and without cyclin-dependent kinase inhibitor 2A (CDKN2A) mutations. METHODS:For this non-population-based study, families were followed prospectively for up to 40 years. A total of 60 families with???3 patients with melanoma were included for analysis: 30 CDKN2A mutation-positive (CDKN2A+) and 30 CDKN2A mutation-negative (CDKN2A-) families. Age at the time of first melanoma and number of melanomas were obtained for each patient and summarized by family or sets (CDKN2A?+?vs CDKN2A-). For set comparisons and categorical variables (occurrence of melanoma in pediatric patients, number of melanomas, number of patients with single or multiple melanomas), the Pearson chi-square or Fisher exact test was used. RESULTS:Regardless of CDKN2A status, melanoma-prone families were found to have 6-fold to 28-fold higher percentages of patients with pediatric melanoma compared with the general population of patients with melanoma in the United States. Within CDKN2A?+?families, pediatric patients with melanoma were significantly more likely to have multiple melanomas compared with their relatives who were diagnosed at age >20 years (71% vs 38%, respectively; P?=?.004). CDKN2A?+?families had significantly higher percentages of pediatric patients with melanoma compared with CDKN2A- families (11.1% vs 2.5%; P?=?.004). CONCLUSIONS:These observations have implications for the prevention of melanoma as well as clinical care for its early detection. Children in melanoma-prone families should have careful sun protection from an early age and skin surveillance to reduce their risk of melanoma.
Project description:BACKGROUND:Germline mutations in telomere-related genes such as POT1 and TERT predispose individuals to familial melanoma. OBJECTIVES:To evaluate the prevalence of germline mutations in POT1 and TERT in a large cohort of Spanish melanoma-prone families (at least two affected first- or second-degree relatives). METHODS:Overall, 228 CDKN2A wild-type melanoma-prone families were included in the study. Screening of POT1 was performed in one affected person from each family and TERT was sequenced in one affected patient from 202 families (26 families were excluded owing to DNA exhaustion/degradation). TERT promoter sequencing was extended to an additional 30 families with CDKN2A mutation and 70 patients with sporadic multiple primary melanoma (MPM) with a family history of other cancers. RESULTS:We identified four families with potentially pathogenic POT1 germline mutations: a missense variant c.233T>C (p.Ile78Thr); a nonsense variant c.1030G>T (p.Glu344*); and two other variants, c.255G>A (r.125_255del) and c.1792G>A (r.1791_1792insAGTA, p.Asp598Serfs*22), which we confirmed disrupted POT1 mRNA splicing. A TERT promoter variant of unknown significance (c.-125C>A) was detected in a patient with MPM, but no germline mutations were detected in TERT promoter in cases of familial melanoma. CONCLUSIONS:Overall, 1·7% of our CDKN2A/CDK4-wild type Spanish melanoma-prone families carry probably damaging mutations in POT1. The frequency of TERT promoter germline mutations in families with melanoma in our population is extremely rare.
Project description:PURPOSE:Carriers of CDKN2A mutations have high risks of melanoma and certain other cancers. In this study we examined the occurrence of tumors among CDKN2A wild type (wt) members of melanoma-prone families with CDKN2A mutations. METHODS:Swedish and US melanoma-prone families with CDKN2A mutations were included. Data was collected on tumors diagnosed among family members. Among the CDKN2A mutated families, members with CDKN2A wt status who were diagnosed with melanoma were designated phenocopies. RESULTS:Of patients with melanoma in the CDKN2A mutated families (n?=?266), 7.1%, were seen among members with CDKN2A wt status (phenocopy rate). Among the CDKN2A wt family members of the CDKN2A mutated families (n?=?256), 7.4% were diagnosed with melanoma. The prospective relative risk for melanomas was significantly higher among the CDKN2A wt subjects compared with population-based controls (7.4 (95% confidence interval 1.7-33.2)), while no elevated risks of nonmelanoma cancers were seen and their offspring did not have significantly elevated risks of melanoma or other cancers. CONCLUSION:Members of CDKN2A mutation carrying families who test negative for their family's mutation have moderately increased risk for melanoma and should, in addition to being considered for continuing dermatologic surveillance, be encouraged to follow sun safety recommendations and practice skin self-exams.
Project description:The presence of pancreatic cancer (PC) in melanoma-prone families has been consistently associated with an increased frequency of CDKN2A mutations, the major high-risk susceptibility gene identified for melanoma. However, the precise relationship between CDKN2A, melanoma and PC remains unknown. We evaluated a recently identified PC susceptibility gene PALB2 using both sequencing and tagging to determine whether PALB2 might explain part of the relationship between CDKN2A, melanoma, and PC. No disease-related mutations were identified from sequencing PALB2 in multiple pancreatic cancer patients or other mutation carrier relatives of PC patients from the eight melanoma-prone families with CDKN2A mutations and PC. In addition, no significant associations were observed between 11 PALB2 tagging SNPs and melanoma risk in 23 melanoma-prone families with CDKN2A mutations or the subset of 11 families with PC or PC-related CDKN2A mutations. The results suggested that PALB2 does not explain the relationship between CDKN2A, melanoma, and pancreatic cancer in these melanoma-prone families.
Project description:Since 1976, melanoma-prone families have been followed at the National Cancer Institute to identify etiologic factors for melanoma. We compared risks of melanoma and other cancers in 1,226 members of 56 families followed for up to 4 decades with population rates in the Surveillance, Epidemiology, and End Results program. All families were tested for mutations in CDKN2A and CDK4; 29 were mutation-positive and 27 mutation-negative. We compared rates of invasive melanomas, both first and second, by family mutation status, with Surveillance, Epidemiology, and End Results program. Comparing three calendar periods of the study, risk of first primary melanoma decreased slightly. Risks of melanoma after first examination, however, were approximately one-third the risks prior to the first examination in both mutation-positive and mutation-negative families. Among patients with melanoma, risk of a second melanoma was increased 10-fold in all families; risk was somewhat higher in mutation-positive families. Risks of other second cancers were increased only for pancreatic cancer after melanoma in mutation-positive families. Over 4 decades, prospective risk of melanoma has decreased substantially in both mutation-positive and mutation-negative families, when melanoma has greatly increased in the general population. TRIAL REGISTRATION:NCI 02-C-0211, ClinicalTrials.gov ID NCT00040352.