These data suggest that mutated Cypher/ZASP can cause DCM and INLVM and identify a mechanistic basis.

Various models of cancer genetics service delivery have been published, and practice guidelines were set forth by the National Society of Genetic Counselors (NSGC) in 2004. While the demand for services has increased, there has not been a comprehensive study of current practice models. An online survey of the NSGC Familial Cancer Risk Counseling Special Interest Group was conducted to study current methods of providing clinical cancer genetics services. Respondents were asked to quantify patient volume, support staff availability, and physician involvement in cases. Two case examples were used to further describe current practices including the number of genetic counseling tasks performed, time spent in these tasks, and number of in-person visits versus phone encounters. Although published cancer genetic counseling guidelines advise a 3-visit model (initial consult, sample draw, and result disclosure), 29.3% of respondents have adopted a 1-visit model, where the sample is drawn at the first visit and phone disclosure replaces the third visit. The content of the initial consult does not vary significantly, and is consistent with the NSGC practice guidelines. Furthermore, 56% report spending >15 min on case preparation, and 27 respondents self-reported redundancy in tasks such as documentation. It appears that a proportion of genetic counselors are following a new model of service delivery. However, insufficient documentation and case preparation are apparent, and many respondents reported lack of support staff as a barrier to efficient patient care. Factors contributing to the variability in current practice, and how they affect efficiency, require further study.

Lynch syndrome is the most common hereditary colorectal cancer syndrome and the most common cause of hereditary endometrial cancer. Identifying and evaluating families for Lynch syndrome is increasing in complexity due to the recognition that: family history-based clinical criteria lack sensitivity and specificity; genetic testing for Lynch syndrome continues to evolve as understanding of the molecular mechanisms underlying it evolves; and the Lynch syndrome phenotype encompasses multiple organ systems and demonstrates overlap with other hereditary cancer syndromes. This document is a summary of considerations when evaluating individuals and families for Lynch syndrome, including information on cancer risks, diagnostic criteria, tumor and genetic testing strategies, and the management of individuals with this condition.

Aim To characterize the frequency of germline mutations associated with Lynch syndrome and review the potential expanded differential diagnoses in very early onset colorectal cancer (CRC) cases without apparent polyposis. Methods Retrospectively reviewed medical records of 96 probands with CRC diagnosed prior to age 36 from three cancer centers. Determined the frequency of germline mutations in probands meeting different clinical criteria used to identify Lynch syndrome. Results Three of 46 (6.5%) single case indicators (probands without additional personal or family history suspicious for Lynch syndrome) were identified to carry a deleterious or suspected deleterious mismatch repair (MMR) mutation compared with 10 of 19 (52.6 %) in the cases meeting at least one additional revised Bethesda guideline, and 11 of 15 (73.3 %) in the cases meeting Amsterdam criteria. Two families without MMR mutations were documented to have a germline APC or TP53 mutation after additional clinical features were identified. Conclusions Our results suggest that single cases of CRC (those without additional personal or family history suspicious of Lynch syndrome) diagnosed prior to age 36 infrequently have identifiable MMR mutations, especially when compared to cases meeting additional criteria. Careful attention to evolving or additional clinical features is warranted and may lead to an alternate genetic diagnosis in families with early onset CRC.