A Randomized Controlled Trial of Disclosing Genetic Risk Information for Alzheimer’s Disease via Telephone

Purpose Telephone disclosure of genetic test results can improve access to services. To date, studies of its impact have focused on return of Mendelian risk information, principally hereditary cancer syndromes. Methods: In a multisite trial of Alzheimer’s disease genetic risk disclosure, asymptomatic adults were randomized to receive test results in-person or via telephone. Primary analyses examined patient outcomes 12 months after disclosure. Results: Data from 257 participants showed that telephone disclosure occurred 7.4 days sooner and were 30% shorter, on average, than in-person disclosure (both p<0.001). Anxiety and depression scores were well below cutoffs for clinical concern across protocols. Comparing telephone and in-person disclosure protocols, 99% CIs of mean differences were within non-inferiority margins on scales assessing anxiety, depression, and test-related distress, but inconclusive about positive impact. No differences were observed on measures of recall and subjective impact. Sub-analyses supported non-inferiority on all outcomes among APOE ε4-negative participants. Sub-analyses were inconclusive for APOE ε4-positive participants, although mean anxiety and depression scores were still well below cutoffs for clinical concern. Conclusion: Telephone disclosure of APOE results and risk for Alzheimer’s disease is generally safe and helps providers meet demands for services, even when results identify an increased risk for disease

Regional differences in awareness and attitudes regarding genetic testing for disease risk and ancestry

Little is known about the lay public’s awareness and attitudes concerning genetic testing and what factors influence their perspectives. The existing literature focuses mainly on ethnic and socioeconomic differences; however, here we focus on how awareness and attitudes regarding genetic testing differ by geographical regions in the US. We compared awareness and attitudes concerning genetic testing for disease risk and ancestry among 452 adults (41% Black and 67% female) in four major US cities, Norman, OK; Cincinnati, OH; Harlem, NY; and Washington, DC; prior to their participation in genetic ancestry testing. The OK participants reported more detail about their personal ancestries (p = 0.02) and valued ancestry testing over disease testing more than all other sites (p < 0.01). The NY participants were more likely than other sites to seek genetic testing for disease (p = 0.01) and to see benefit in finding out more about one’s ancestry (p = 0.02), while the DC participants reported reading and hearing more about genetic testing for African ancestry than all other sites (p < 0.01). These site differences were not better accounted for by sex, age, education, self-reported ethnicity, religion, or previous experience with genetic testing/counseling. Regional differences in awareness and attitudes transcend traditional demographic predictors, such as ethnicity, age and education. Local sociocultural factors, more than ethnicity and socioeconomic status, may influence the public’s awareness and belief systems, particularly with respect to genetics

CDH1 Missense Variant c.1679C>G (p.T560R) Completely Disrupts Normal Splicing through Creation of a Novel 5' Splice Site.

Disease-causing germline mutations in CDH1 cause Hereditary Diffuse Gastric Cancer (HDGC). For patients who meet the HDGC screening criteria, the identification and classification of the sequence variants found in CDH1 are critical for risk management of patients. In this report, we describe a germline CDH1 c.1679C>G (p.T560R) variant identified in a 50 year old man who was diagnosed with gastric cancer with a strong family history of gastric cancer (one living brother was diagnosed with gastric cancer at 63 and another brother died of gastric cancer at 45). cDNA analysis, involving fragment analysis and cloning, indicated that the p.T560R mutation created a novel 5' splice donor site, which led to a novel transcript with a 32 nucleotide deletion in exon 11. This abnormal transcript putatively produces a truncated CDH1 protein (E-cadherin) of 575 amino acids instead of 882. We also demonstrated that the variant completely abolishes normal splicing as the mutant allele does not generate any normal transcript. Furthermore, the CDH1 c.1679C>G (p.T560R) variant segregated with gastric cancer in all three family members affected with gastric cancer in this family. These results support the conclusion that CDH1 c.1679C>G (p.T560R) variant is a pathogenic mutation and contributes to HDGC through disruption of normal splicing

O2–01–08: Comparing the impact of a condensed vs extended protocol for disclosure of APOE to relatives of patients with AD: The reveal study

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153026/1/alzjjalz200704051.pd

P3‐488: The impact of an education and risk evaluation protocol on perceived benefits and risks of genetic susceptibility testing for Alzheimer’s disease

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152708/1/alzjjalz2008052059.pd

Association of CDH1 Germline Variants and Colon Polyp Phenotypes in Patients With Hereditary Diffuse Gastric Cancer

Background and Aims: Germline CDH1 variants resulting in E-cadherin loss of function result in an increased risk of diffuse type gastric cancer and lobular type breast cancer. However, the risk of developing other epithelial neoplasms, specifically colorectal cancer, is unknown. Methods: Patients enrolled in a prospective natural history study of hereditary gastric cancer who underwent at least one colonoscopy were evaluated. Results: Of 300 patients with CDH1 pathogenic or likely pathogenic variants, 85 underwent colonoscopy. More than half of patients (56%, 48/85) had at least one colorectal polyp. Most of those patients (83%, 40/48) had at least one precancerous polyp (adenoma or sessile serrated lesion). More than half (56%) of patients aged less than 45 years had a colorectal polyp. Of those with polyps, the most frequent CDH1 variant type was canonical splice site (27%, 13/48) followed by nonsense (21%, 10/48). There was no association between CDH1 variant type and increased likelihood of colorectal polyps. Conclusion: In summary, a majority of CDH1 variant carriers who underwent colonoscopy had colorectal polyps detected and most subjects were aged less than 45 years. This study of colorectal cancer risk based on the prevalence of colorectal polyps in the CDH1 population requires further investigation to appropriately counsel patients on colorectal cancer screening. Clinical trial registry website: https://clinicaltrials.gov/. Clinical trial number: NCT03030404

P‐004: Incorporating ethnicity into genetic risk assessment for Alzheimer’s disease: The reveal study experience

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152651/1/alzjjalz200704220.pd

<i>In silico</i> prediction of the <i>CDH1</i> p.T560R variant.

<p>Prediction of the potential effects of the <i>CDH1 c</i>.<i>1679 C>G</i> (p.T560R) alteration on normal mRNA splicing. Top panel: reference sequence; bottom panel: mutated sequence. The text at the left of each panel represents the names of the tools used to predict splice site strength. The number ranges indicate the strength of each target sequence in each prediction tool with the upper range being the perfect match. The reference sequence and mutated sequences are shown at the bottom of each panel with nucleotide positions indicated above. Blue vertical bars indicate 5’ (donor) site. The height of each bar is proportional to the maximum possible score computed by the corresponding algorithm.</p

A randomized noninferiority trial of condensed protocols for genetic risk disclosure of Alzheimer’s disease

IntroductionConventional multisession genetic counseling is currently recommended when disclosing apolipoprotein E (APOE) genotype for the risk of Alzheimer’s disease (AD) in cognitively normal individuals. The objective of this study was to evaluate the safety of brief disclosure protocols for disclosing APOE genotype for the risk of AD.MethodsA randomized, multicenter noninferiority trial was conducted at four sites. Participants were asymptomatic adults having a firstâ degree relative with AD. A standard disclosure protocol by genetic counselors (SPâ GC) was compared with condensed protocols, with disclosures by genetic counselors (CPâ GC) and by physicians (CPâ MD). Preplanned coâ primary outcomes were anxiety and depression scales 12 months after disclosure.ResultsThree hundred and fortyâ three adults (mean age 58.3, range 33â 86 years, 71% female, 23% African American) were randomly assigned to the SPâ GC protocol (n = 115), CPâ GC protocol (n = 116), or CPâ MD protocol (n = 112). Mean postdisclosure scores on all outcomes were well below cutâ offs for clinical concern across protocols. Comparing CPâ GC with SPâ GC, the 97.5% upper confidence limits at 12 months after disclosure on coâ primary outcomes of anxiety and depression ranged from a difference of 1.2 to 2.0 in means (all P < .001 on noninferiority tests), establishing noninferiority for condensed protocols. Results were similar between European Americans and African Americans.ConclusionsThese data support the safety of condensed protocols for APOE disclosure for those free of severe anxiety or depression who are actively seeking such information.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152725/1/alzjjalz201410014.pd