Genetic testing of children at risk for adult onset conditions: when is testing indicated?

Pediatric manifestations of Lynch Syndrome: A single center experience

Lynch syndrome is an autosomal dominant condition caused by a heterozygous variation in one of the DNA mismatch repair (MMR) genes that pre-disposes individuals to early onset colorectal cancers and other malignancies. Lynch syndrome is generally considered an adult-onset disorder, with malignancy rarely manifesting in childhood. Colorectal cancer is extremely rare in children, but hereditary syndromes including Lynch syndrome are an important cause. We aimed to assess the frequency and clinical course of children with Lynch syndrome associated pediatric colorectal cancers at our institution over the last 20 years.

In this retrospective study, we describe four cases of children with Lynch syndrome-associated colorectal cancers age 14–17 years at diagnosis. All patients were diagnosed with Lynch syndrome after diagnosis, despite three of them having family histories consistent with Lynch syndrome.

This series highlights a rare but important cause of pediatric malignancy and points to the need for early education on colorectal cancer warning symptoms and open discussion about this condition in affected families. It also illustrates the need for a thorough family history and a high level of suspicion for Lynch syndrome in children based on family background, as early detection may be key to improving cancer outcomes.

Helping Couples Fulfill the "Highest of Life's Goals": Mate Selection, Marriage Counselling, and Genetic Counseling in United States

This article traces the history of modern genetic counseling to mate selection and marriage counselling practices of the early-20th century. Mate selection revolved around a belief that human heredity could be improved and genetic diseases eradicated through better breeding. Marriage counselling, though interested in reproduction, was also concerned with the emotional and psychological well-being of couples. These two practices coalesced most obviously in the work of well-known geneticist Sheldon Reed. Even as marriage and genetic counselling diverged in the post-WWII period, vestiges of these practices remain in contemporary counseling experiences with family planning and genetic screening programs. Emphasizing points of continuity between "positive" eugenic ideologies and modern genetic practices elaborates the diverse origins of genetic counseling. It also exposes how genetic counselors have become involved in genetic enterprises beyond standard clinical settings, and prods at key issues in the interaction between genetic science and social values.

Geographical variation and factors associated with colorectal cancer mortality in a universal health care system

OBJECTIVE

To investigate the geographical variation and small geographical area level factors associated with colorectal cancer (CRC) mortality.

METHODS

Information regarding CRC mortality was obtained from the population-based Manitoba Cancer Registry, population counts were obtained from Manitoba's universal health care plan Registry and characteristics of the area of residence were obtained from the 2001 Canadian census. Bayesian spatial Poisson mixed models were used to evaluate the geographical variation of CRC mortality and Poisson regression models for determining associations with CRC mortality. Time trends of CRC mortality according to income group were plotted using joinpoint regression.

RESULTS

The southeast (mortality rate ratio [MRR] 1.31 [95% CI 1.12 to 1.54) and southcentral (MRR 1.62 [95% CI 1.35 to 1.92]) regions of Manitoba had higher CRC mortality rates than suburban Winnipeg (Manitoba's capital city). Between 1985 and 1996, CRC mortality did not vary according to household income; however, between 1997 and 2009, individuals residing in the highest-income areas were less likely to die from CRC (MRR 0.77 [95% CI 0.65 to 0.89]). Divergence in CRC mortality among individuals residing in different income areas increased over time, with rising CRC mortality observed in the lowest income areas and declining CRC mortality observed in the higher income areas.

CONCLUSIONS

Individuals residing in lower income neighbourhoods experienced rising CRC mortality despite residing in a jurisdiction with universal health care and should receive increased efforts to reduce CRC mortality. These findings should be of particular interest to the provincial CRC screening programs, which may be able to reduce the disparities in CRC mortality by reducing the disparities in CRC screening participation.

Update on pediatric cancer predisposition syndromes

Hereditary cancer syndromes in children and adolescents are becoming more recognized in the field of pediatric hematology/oncology. A recent workshop held at the American Society of Pediatric Hematology/Oncology (ASPHO) 2012 Annual Meeting included several interactive sessions related to specific familial cancer syndromes, genetic testing and screening, and ethical issues in caring for families with inherited cancer risk. This review highlights the workshop presentations, including a brief background about pediatric cancer predisposition syndromes and the importance of learning about them for the practicing pediatric hematologists/oncologists. This is followed by a brief summary of the newly described cancer predisposition syndromes including Rhabdoid Tumor Predisposition Syndrome, Hereditary Paragangliomas and Pheochromocytoma Syndrome, and Familial Pleuropulmonaryblastoma Tumor Predisposition (DICER1) Syndrome. The next section covers genetic testing and screening for pediatric cancer predisposition syndromes. Ethical issues are also discussed including preimplantation genetic diagnosis or testing (PGD/PGT), suspicious lesions found on tumor screening, and incidental mutations discovered by whole genome sequencing. Finally, the perspective of a family with Li-Fraumeni Syndrome is shared.

Identification, management, and evaluation of children with cancer-predisposition syndromes

A substantial proportion of childhood cancers are attributable to an underlying genetic syndrome or inherited susceptibility. Recognition of affected children allows for appropriate cancer risk assessment, genetic counseling, and testing. Identification of individuals who are at increased risk to develop cancers during childhood can guide cancer surveillance and clinical management, which may improve outcomes for both the patient and other at-risk relatives. The information provided through this article will focus on the current complexities involved in the evaluation and management of children with cancer-predisposing genetic conditions and highlight remaining questions for discussion.