A novel recurrent mutation in MITF predisposes to familial and sporadic melanoma.

So far, two genes associated with familial melanoma have been identified, accounting for a minority of genetic risk in families. Mutations in CDKN2A account for approximately 40% of familial cases, and predisposing mutations in CDK4 have been reported in a very small number of melanoma kindreds. Here we report the whole-genome sequencing of probands from several melanoma families, which we performed in order to identify other genes associated with familial melanoma. We identify one individual carrying a novel germline variant (coding DNA sequence c.G1075A; protein sequence p.E318K; rs149617956) in the melanoma-lineage-specific oncogene microphthalmia-associated transcription factor (MITF). Although the variant co-segregated with melanoma in some but not all cases in the family, linkage analysis of 31 families subsequently identified to carry the variant generated a log of odds (lod) score of 2.7 under a dominant model, indicating E318K as a possible intermediate risk variant. Consistent with this, the E318K variant was significantly associated with melanoma in a large Australian case-control sample. Likewise, it was similarly associated in an independent case-control sample from the United Kingdom. In the Australian sample, the variant allele was significantly over-represented in cases with a family history of melanoma, multiple primary melanomas, or both. The variant allele was also associated with increased naevus count and non-blue eye colour. Functional analysis of E318K showed that MITF encoded by the variant allele had impaired sumoylation and differentially regulated several MITF targets. These data indicate that MITF is a melanoma-predisposition gene and highlight the utility of whole-genome sequencing to identify novel rare variants associated with disease susceptibility.

Population-based, case-control-family design to investigate genetic and environmental influences on melanoma risk: Australian Melanoma Family Study.

Discovering and understanding genetic risk factors for melanoma and their interactions with phenotype, sun exposure, and other risk factors could lead to new strategies for melanoma control. This paper describes the Australian Melanoma Family Study, which uses a multicenter, population-based, case-control-family design. From 2001 to 2005, the authors recruited 1,164 probands including 629 cases with histopathologically confirmed, first-primary cutaneous melanoma diagnosed before age 40 years, 240 population-based controls frequency matched for age, and 295 spouse/friend controls. Information on lifetime sun exposure, phenotype, and residence history was collected for probands and nearly 4,000 living relatives. More than 3,000 subjects donated a blood sample. Proxy-reported information was collected for childhood sun exposure and deceased relatives. Important features of this study include the population-based, family-based design; a focus on early onset disease; probands from 3 major cities differing substantially in solar ultraviolet exposure and melanoma incidence; a population at high risk because of high ultraviolet exposure and susceptible pigmentation phenotypes; population-based, spouse/friend, and sibling controls; systematic recruitment of relatives of case and control probands; self and parent reports of childhood sun exposure; and objective clinical skin examinations. The authors discuss methodological and analytical issues related to the study design and conduct, as well as the potentially novel insights the study can deliver.

How do researchers manage genetic results in practice? The experience of the multinational Colon Cancer Family Registry.

There is consensus internationally that research participants should be offered the opportunity to receive clinically relevant genetic information identified through research, but there is little empirical peer-reviewed work documenting this process. We report the experience of conducting genetic research with nearly 35,000 participants in the Colon Cancer Family Registry, based in the USA, Canada, Australia, and New Zealand. Investigators from six multinational sites provided information about disclosure protocols, implementation, and uptake of genetic results and made suggestions to inform practice. Across 5 of the 6 registry sites, 1,634 participants in families with mismatch repair or MutYH gene mutations have been offered results. Participant uptake ranged from 56 to 86 %. Researchers faced significant challenges in the effort to return results. We offer suggestions in five key areas: (1) planning for the disclosure process, (2) participant information, (3) autonomy of participants, (4) monitoring scientific progress, and (5) involvement of stakeholders. Despite increasing discussion of the importance of returning incidental findings from genetic research, this paper highlights the considerable diversity, challenges, and costs faced in practice when returning expected findings with established utility and validity. We argue that more work is needed to ensure that genetic results in research are optimally managed.

Genome-wide association study identifies a new melanoma susceptibility locus at 1q21.3.

We performed a genome-wide association study of melanoma in a discovery cohort of 2,168 Australian individuals with melanoma and 4,387 control individuals. In this discovery phase, we confirm several previously characterized melanoma-associated loci at MC1R, ASIP and MTAP-CDKN2A. We selected variants at nine loci for replication in three independent case-control studies (Europe: 2,804 subjects with melanoma, 7,618 control subjects; United States 1: 1,804 subjects with melanoma, 1,026 control subjects; United States 2: 585 subjects with melanoma, 6,500 control subjects). The combined meta-analysis of all case-control studies identified a new susceptibility locus at 1q21.3 (rs7412746, P = 9.0 × 10(-11), OR in combined replication cohorts of 0.89 (95% CI 0.85-0.95)). We also show evidence suggesting that melanoma associates with 1q42.12 (rs3219090, P = 9.3 × 10(-8)). The associated variants at the 1q21.3 locus span a region with ten genes, and plausible candidate genes for melanoma susceptibility include ARNT and SETDB1. Variants at the 1q21.3 locus do not seem to be associated with human pigmentation or measures of nevus density.

Is uptake of genetic testing for colorectal cancer influenced by knowledge of insurance implications?

OBJECTIVE: To assess whether knowledge of insurance implications influenced uptake of genetic testing by participants in a research study of the causes of colorectal cancer. DESIGN, SETTING AND PARTICIPANTS: Analysis of uptake of genetic testing by participants in the population-based Victorian Colorectal Cancer Family Study during two periods: from 1999 to 2003, when participants were not informed of any potential effect of genetic testing conducted during the study on their eligibility for new insurance policies; and from 2003 to 2006, when the protocol was changed to provide participants with information on the potential effect of genetic testing on insurance eligibility. MAIN OUTCOME MEASURE: Uptake of genetic testing for germline mutations in DNA mismatch repair (MMR) genes at a family cancer clinic. RESULTS: The proportion of participants who declined genetic testing among those informed of insurance implications was more than double the proportion among those without this knowledge (29/59 [49%] v 9/47 [19%]; P = 0.002). This difference could not be explained statistically by adjusting for measured putative predictors. CONCLUSION: Identification of people with a mutation in an MMR gene has clinical importance, and such screening may be a cost-effective way to reduce the burden of colorectal cancer in the community. If people are choosing not to obtain genetic information because of how it will affect their eligibility for insurance, reforms to existing insurance practices are indicated.

Common sequence variants on 20q11.22 confer melanoma susceptibility.

We conducted a genome-wide association pooling study for cutaneous melanoma and performed validation in samples totaling 2,019 cases and 2,105 controls. Using pooling, we identified a new melanoma risk locus on chromosome 20 (rs910873 and rs1885120), with replication in two further samples (combined P < 1 x 10(-15)). The per allele odds ratio was 1.75 (1.53, 2.01), with evidence for stronger association in early-onset cases.