Preferences for return of incidental findings from genome sequencing among women diagnosed with breast cancer at a young age.

While experts have made recommendations, information is needed regarding what genome sequencing results patients would want returned. We investigated what results women diagnosed with breast cancer at a young age would want returned and why. We conducted 60 semi-structured, in-person individual interviews with women diagnosed with breast cancer at age 40 or younger. We examined interest in six types of incidental findings and reasons for interest or disinterest in each type. Two coders independently coded interview transcripts; analysis was conducted using NVivo 10. Most participants were at least somewhat interested in all six result types, but strongest interest was in actionable results (i.e. variants affecting risk of a preventable or treatable disease and treatment response). Reasons for interest varied between different result types. Some participants were not interested or ambivalent about results not seen as currently actionable. Participants wanted to be able to choose what results are returned. Participants distinguished between types of individual genome sequencing results, with different reasons for wanting different types of information. The findings suggest that a focus on actionable results can be a common ground for all stakeholders in developing a policy for returning individual genome sequencing results.

A practical approach to familial and hereditary colorectal cancer.

Recent genetic research has isolated the primary genetic defect underlying many of the hereditary colorectal cancer syndromes. Obtaining a detailed family history is the first step in identifying individuals at increased risk of developing colorectal cancer. Once identified, individuals and their families may benefit from earlier, more intensified surveillance, prophylactic surgery, cancer risk assessment and education, and genetic testing. Clinicians, especially those with many patients with colorectal cancer in their practice, must be able to address the complex issues associated with the familial and hereditary colorectal cancer syndromes. A well-integrated partnership among colorectal surgeons, gastroenterologists, oncologists, and medical geneticists is necessary to address these complex issues and provide comprehensive medical care.

An 11-year-old boy with mosaic ring chromosome 6 and dilated aortic root.

Autosomal ring chromosomes are rare abnormalities that are inherently unstable. Children with ring chromosome 6 have a wide range of intellectual functioning and congenital anomalies. Cardiac lesions are rarely reported with this chromosome abnormality. We report on a 11-year-old boy with mosaic ring chromosome 6 and a dilated aortic root.

12-year-old male with Elejalde syndrome (neuroectodermal melanolysosomal disease).

Neuroectodermal melanolysosomal disease, also known as Elejalde syndrome, is a rare syndrome characterized by silvery hair, pigment abnormalities, and profound central nervous system dysfunction. It is similar to the Chediak-Higashi and Griscelli syndromes, although these syndromes are associated with severe immunologic dysfunction. We report on a 12-year-old male with Elejalde syndrome and compare the Elejalde, Chediak-Higashi, and Griscelli syndromes.

Cancer and Peutz-Jeghers Syndrome: A Review.

Peutz-Jeghers syndrome is a dominantly inherited polyposis syndrome characterized by hamartomatous polyps of the gastrointestinal tract and pigmented lesions of the skin. Since its description, much debate has centered on the true malignancy risk of Peutz-Jeghers syndrome including malignancy within and outside the gastrointestinal tract. Rare tumors such as adenoma malignum of the cervix occur in Peutz-Jeghers syndrome. Likewise, more common cancers occur at younger ages in Peutz-Jeghers syndrome. Children may manifest symptoms of this disease including gastrointestinal complications and malignancy. The gene associated with this condition remains unidentified.

Perceptions of genetic risk assessment and education among first-degree relatives of colorectal cancer patients and implications for physicians.

BACKGROUND: Genetic risk assessment and education is a clinical service that provides an opportunity for individuals with a strong family history of cancer to understand their risk better, identify a screening regimen and discuss benefits and limitations of genetic testing. OBJECTIVES: The aim of this study was to assess knowledge of and attitudes to genetic risk assessment and education among first-degree relatives of patients with colorectal cancer. METHODS: We conducted focus groups among first-degree relatives of patients with colorectal cancer to assess perceptions of genetic risk assessment and education. In the groups, we elicited reactions using two definitions of genetic risk assessment and education-one brief and one more detailed-that might be used by a health practitioner during the referral process. RESULTS: Findings revealed a number of misconceptions and concerns including: (i) what is required to prepare for a session and a lack of desire to collect a family history; (ii) what is involved in a session (including assuming that genetic testing is always included in a session); (iii) distrust over accuracy and possible subjectivity of information provided; and (iv) fear of the effect that participation in a session might have on insurance status. CONCLUSIONS: The findings suggest that health practitioners should educate individuals about genetic risk assessment and education during the initial referral process. Further studies should explore how best to do this.

Assignment of a second Charcot-Marie-Tooth type II locus to chromosome 3q.

Charcot-Marie-Tooth disease (CMT) is the most common inherited motor and sensory neuropathy. The neuronal form of this disorder is referred to as Charcot-Marie-Tooth type II disease (CMT2). CMT2 is usually inherited as an autosomal dominant trait with a variable age at onset of symptoms associated with progressive axonal neuropathy. In some families, the locus that predisposes to CMT2 has been demonstrated to map to the distal portion of the short arm of chromosome 1. Other families with CMT2 do not show linkage with 1p markers, suggesting genetic heterogeneity in CMT2. We investigated linkage in a single large kindred with autosomal dominant CMT2. The gene responsible for CMT2 in this kindred (CMT2B) was mapped to the interval between the microsatellite markers D3S1769 and D3S1744 in the 3q13-22 region. Study of additional CMT2 kindreds should serve to further refine the disease gene region and may ultimately lead to the identification of a gene defect that underlies the CMT2 phenotype.

Mutations in MLH1 are more frequent than in MSH2 in sporadic colorectal cancers with microsatellite instability.

The microsatellite instability that is a feature of tumors in patients with hereditary nonpolyposis colorectal cancer (HNPCC) is a consequence of defective DNA mismatch repair. Mutations in the DNA mismatch repair genes MSH2 and MLH1 may account for up to 90% of HNPCC kindreds. Microsatellite instability is also seen in 10-16% of sporadic colorectal cancers. A limited number of MSH2 and MLH1 mutations have been described for sporadic colorectal cancers. In this study, we screened 12 primary sporadic colorectal cancers with microsatellite instability for mutations in MSH2 and MLH1 by using reverse transcription-polymerase chain reaction (RT-PCR) and single-strand-conformation-variant (SSCV) analysis. Eight mutations were identified in six tumors. One mutation in MLH1 was found to be present in the patient's germline DNA. Four tumors had somatic mutations in MLH1, and, in two of these tumors, two different mutations were identified. A single tumor had a somatic MSH2 mutation. Our observations suggest that MLH1 is mutated more frequently than MSH2 in sporadic colorectal cancers with microsatellite instability.

Maternal age specific risk rate estimates for Down syndrome among live births in whites and other races from Ohio and metropolitan Atlanta, 1970-1989.

Our primary objective was to estimate, by one year and five year intervals, maternal age specific risk rates for Down syndrome among whites and among other races from two different populations, metropolitan Atlanta and south west Ohio, using live birth and prenatally diagnosed cases ascertained during 1970-1989. The five year estimates were also calculated separately for each of the five four year periods during these 20 years. Additionally, we compared two different methods of estimating these risk rates by using a third population of whites, and compared two different statistical methods of smoothing the risk rates. The results indicate good agreement between the metropolitan Atlanta and south west Ohio estimates within races, but show a statistically significant difference between the two race categories. Because 86% of live births in the "other races" category in the combined population are to blacks, these data may be seen as the first estimates of maternal age specific risk rates for Down syndrome among blacks calculated by one year intervals. We found excellent agreement in the risk rate estimates among the five four year time periods, between the estimates obtained by using the two different methods of estimation, and between the estimates obtained using the two different methods of statistical smoothing. Our estimated risk rates for white women in their 20s strongly reinforce those from previous studies currently being used for genetic counselling purposes. While we did find somewhat higher rates for women under 20, and increasingly higher rates for those over 30 years of age, these differences are not substantial. Thus, this study in general supports the risk rates estimated from data collected mostly during the 1960s and 1970s.

Predictive DNA testing and prophylactic thyroidectomy in patients at risk for multiple endocrine neoplasia type 2A.

BACKGROUND: Missense germ-line mutations in the RET protooncogene are associated with multiple endocrine neoplasia type 2A (MEN 2A). Detection of these mutant alleles in kindred members predicts disease inheritance and provides the basis for preventative thyroidectomy. METHODS: A polymerase chain reaction (PCR)-based genetic test for the 19 known RET mutations was designed to study 132 members of 7 kindreds with MEN 2A. Haplotypes also were constructed using genetic markers flanking the MEN 2A locus. Plasma calcitonin (CT) concentrations were determined before and after provocative testing. RESULTS: Direct DNA testing and haplotype analysis showed that 21 of 58 kindred members at risk for disease had inherited a mutation in the RET protooncogene associated with MEN 2A. Plasma CT concentrations were elevated in 9 of the 21 family members, but were normal in 12. After genetic counseling, 13 of the 21 kindred members (6 with normal and seven with elevated plasma CT levels), consented to immediate thyroidectomy. In each patient, the resected thyroid gland showed C-cell hyperplasia with or without medullary thyroid carcinoma. There were no metastases to regional lymph nodes, and postoperative stimulated plasma CT levels were normal. CONCLUSION: The PCR-based direct DNA test for RET mutations is accurate, rapid, and reproducible. For all 132 individuals evaluated, the results of direct DNA analysis were consistent with haplotype studies. The direct test for mutations in the RET protooncogene is the preferred method for screening MEN 2A kindreds. In family members who have inherited a RET mutation, total thyroidectomy is indicated, regardless of the plasma CT values.