? To identify the gene predisposing to Peutz-Jeghers syndrome through positionalcandidate and positional cloning strategies.
? To study the role of the identified gene in sporadic and hereditary tumorigenesis.
The gene predisposing to Peutz-Jeghers syndrome (PJS) has recently been localized to chromosome l9p by the participants. The ultimate objective of this work is to identify the gene predisposing to PJS, and to determine the role of the identified gene in sporadic tumorigenesis. The importance of this goal is related to two aspects: 1) For PJS families the identification of the gene gives the opportunity to undertake predictive genetic testing. This is of benefit, because presently asymptomatic at risk individuals are recommended to undergo clinical screening procedures aimed at early tumor detection (though the screening is far less extensive than, for example, in hereditary nonpolyposis colorectal cancer kindreds). Genetic testing should be offered to the families only after appropriate genetic counseling, and at first in a research environment. The long-term objective is to understand the pathogenetic mechanisms underlying the syndrome, in order to be able to prevent tumor formation in the affected individuals. 2) For cancer research in general, the goal is to identify a novel tumor suppressor gene, which is likely to have relevance in the tumorigenesis of multiple organ systems. As the cancer spectrum in PJS seems to include at least gastrointestinal, breast, ovarian and testicular malignancies, it is possible that sporadic forms of these tumors arise in part from the background of somatic PJS gene mutations. The previous examples of e.g. familial adenomatous polyposis, Li-Fraumeni -syndrome and hereditary retinoblastoma have shown that a gene underlying a rare hereditary cancer predisposition syndrome can play a major role in sporadic tumors that are prevalent in the general population.
To achieve the objectives the following resources are available: 1) High throughput molecular genetic laboratory with extensive experience on identification of hereditary disease genes, with special focus on hereditary colorectal cancer.
2) Clinical expertise and scrutinized families that are essential bases for gene identification studies.
3) An almost complete and well characterized cosmid contig across the region of interest, facilitating greatly the positional candidate / positional cloning efforts that should lead to the gene identification.
Cancer predisposition, polyposis, tumor suppressor, hamartoma, breast, gastrointetinal, colorectal, gene identification
Funding SchemeCSC - Cost-sharing contracts
WC2A 3PX London