Screening for hemochromatosis and iron overload: satisfaction with results notification and understanding of mailed results in unaffected participants of the HEIRS study

Genetic counseling and testing for Asian Americans: a systematic review

PURPOSE

Asian Americans have been understudied in the literature on genetic and genomic services. The current study systematically identified, evaluated, and summarized findings from relevant qualitative and quantitative studies on genetic health care for Asian Americans.

METHODS

A search of five databases (1990 to 2018) returned 8,522 unique records. After removing duplicates, abstract/title screening, and full text review, 47 studies met inclusion criteria. Data from quantitative studies were converted into "qualitized data" and pooled together with thematic data from qualitative studies to produce a set of integrated findings.

RESULTS

Synthesis of results revealed that (1) Asian Americans are under-referred but have high uptake for genetic services, (2) linguistic/communication challenges were common and Asian Americans expected more directive genetic counseling, and (3) Asian Americans' family members were involved in testing decisions, but communication of results and risk information to family members was lower than other racial groups.

CONCLUSION

This study identified multiple barriers to genetic counseling, testing, and care for Asian Americans, as well as gaps in the research literature. By focusing on these barriers and filling these gaps, clinical genetic approaches can be tailored to meet the needs of diverse patient groups, particularly those of Asian descent.

The Clinical Sequencing Evidence-Generating Research Consortium: Integrating Genomic Sequencing in Diverse and Medically Underserved Populations

The Clinical Sequencing Evidence-Generating Research (CSER) consortium, now in its second funding cycle, is investigating the effectiveness of integrating genomic (exome or genome) sequencing into the clinical care of diverse and medically underserved individuals in a variety of healthcare settings and disease states. The consortium comprises a coordinating center, six funded extramural clinical projects, and an ongoing National Human Genome Research Institute (NHGRI) intramural project. Collectively, these projects aim to enroll and sequence over 6,100 participants in four years. At least 60% of participants will be of non-European ancestry or from underserved settings, with the goal of diversifying the populations that are providing an evidence base for genomic medicine. Five of the six clinical projects are enrolling pediatric patients with various phenotypes. One of these five projects is also enrolling couples whose fetus has a structural anomaly, and the sixth project is enrolling adults at risk for hereditary cancer. The ongoing NHGRI intramural project has enrolled primarily healthy adults. Goals of the consortium include assessing the clinical utility of genomic sequencing, exploring medical follow up and cascade testing of relatives, and evaluating patient-provider-laboratory level interactions that influence the use of this technology. The findings from the CSER consortium will offer patients, healthcare systems, and policymakers a clearer understanding of the opportunities and challenges of providing genomic medicine in diverse populations and settings, and contribute evidence toward developing best practices for the delivery of clinically useful and cost-effective genomic sequencing in diverse healthcare settings.

Impact of delivery models on understanding genomic risk for type 2 diabetes

BACKGROUND

Genetic information, typically communicated in-person by genetic counselors, can be challenging to comprehend; delivery of this information online--as is becoming more common--has the potential of increasing these challenges.

METHODS

To address the impact of the mode of delivery of genomic risk information, 300 individuals were recruited from the general public and randomized to receive genomic risk information for type 2 diabetes mellitus in-person from a board-certified genetic counselor or online through the testing company's website.

RESULTS

Participants were asked to indicate their genomic risk and overall lifetime risk as reported on their test report as well as to interpret their genomic risk (increased, decreased, or same as population). For each question, 59% of participants correctly indicated their risk. Participants who received their results in-person were more likely than those who reviewed their results on-line to correctly interpret their genomic risk (72 vs. 47%, p = 0.0002) and report their actual genomic risk (69 vs. 49%, p = 0.002).

CONCLUSIONS

The delivery of personal genomic risk through a trained health professional resulted in significantly higher comprehension. Therefore, if the online delivery of genomic test results is to become more widespread, further evaluation of this method of communication may be needed to ensure the effective presentation of results to promote comprehension.

Delivering pharmacogenetic testing in a primary care setting

Pharmacogenetic testing refers to a type of genetic test to predict a patient’s likelihood to experience an adverse event or not respond to a given drug. Despite revision to several labels of commonly prescribed drugs regarding the impact of genetic variation, the use of this testing has been limited in many settings due to a number of factors. In the primary care setting, the limited office time as well as the limited knowledge and experience of primary care practitioners have likely attributed to the slow uptake of pharmacogenetic testing. This paper provides talking points for primary care physicians to discuss with patients when pharmacogenetic testing is warranted. As patients and physicians become more familiar and accepting of pharmacogenetic testing, it is anticipated that discussion time will be comparable to that of other clinical tests.

To tell or not to tell - what to do about p.C282Y heterozygotes identified by HFE screening

Hereditary hemochromatosis (HH) is a common preventable disorder of iron overload that can result in liver cirrhosis and reduced lifespan. Most HH is due to homozygosity for the HFE p.C282Y substitution. We conducted a study of screening for p.C282Y in high schools where p.C282Y heterozygotes (CY) individuals were informed of their genotype by letter. We studied whether these individuals understood the implications of their genotype, whether this resulted in anxiety or reduced health perception and whether cascade testing was higher in families of CY than wild-type homozygous (CC) individuals. We found 586 of 5757 (1 in 10) screened individuals were CY. One month after receiving their result, 83% correctly answered that they have one copy of p.C282Y. There was no adverse change in anxiety or health perception from prior to screening to 1 month after receiving results. Significantly more family members of CY individuals than CC individuals were informed about HH and had testing for HH. In conclusion, we found that informing CY individuals of their genotype does not increase anxiety and the implications are generally well understood. This leads to cascade testing in a minority of families. CY individuals should be informed of their genetic status when identified by population screening.

Effect of ambiguous hemochromatosis gene test results on physician utilization

BACKGROUND

Genetic test results may be available to greater numbers of people through genetic screening projects and other means. The effects of widespread genetic testing and notification of genetic test results, particularly added costs through increased physician utilization, have not been clearly established.

METHODS

A primary care-based cohort of 20,306 participants (Hemochromatosis and Iron Overload Study, Ontario site) were tested for the C282Y and H63D mutations of the HFE gene and for abnormal serum ferritin (SF) and transferrin saturation levels. The primary outcome variable was the total number of physician claims per patient after genetic test notification by mail. Multiple Poisson regression was used to adjust for age, sex, baseline SF, diagnoses of arthritis, diabetes, heart failure and impotence, self-rated health, and the number of claims during the 12 months before notification of results. The reference group had no HFE mutations (wild type) and normal transferrin saturation/SF values.

RESULTS

Participants with an ambiguous hemochromatosis gene test and normal iron levels had statistically significantly higher average physician utilization of 3.0%. Participants with HFE mutations (excluding C282Y homozygotes) and elevated iron values showed a 6% increase in physician utilization.

CONCLUSIONS

The health effects, if any, of increased utilization in heterozygotes or those with mild ferritin elevations are unknown but are unlikely to be large at the population level. Ambiguous genetic test results are associated with increased physician service use and should be considered when assessing the complete societal costs of widespread genetic testing.

Screening for iron overload: lessons from the hemochromatosis and iron overload screening (HEIRS) study

BACKGROUND

The HEmochromatosis and IRon Overload Screening (HEIRS) Study provided data on a racially, ethnically and geographically diverse cohort of participants in North America screened from primary care populations.

METHODS

A total of 101,168 participants were screened by testing for HFE C282Y and H63D mutations, and measuring serum ferritin concentration and transferrin saturation. In the present review, lessons from the HEIRS Study are highlighted in the context of the principles of screening for a medical disease as previously outlined by the World Health Organization.

RESULTS

Genetic testing is well accepted, with minimal risk of discrimination. Transferrin saturation has high biological variability and relatively low sensitivity to detect HFE C282Y homozygotes, which limits its role as a screening test. Symptoms attributable to HFE C282Y homozygosity are no more common in individuals identified by population screening than in control subjects.

CONCLUSIONS

Generalized population screening in a primary care population as performed in the HEIRS Study is not recommended. There may be a role for focused screening in Caucasian men, with some debate regarding genotyping followed by phenotyping, or phenotyping followed by genotyping.

Potential nonresponse bias in a clinical examination after initial screening using iron phenotyping and HFE genotyping in the hemochromatosis and iron overload screening study

BACKGROUND

Little is known about the factors affecting participation in clinical assessments after HEmochromatosis and IRon Overload Screening.

METHODS

Initial screening of 101,168 primary care patients in the HEmochromatosis and IRon Overload Screening study was performed using serum iron measures and hemochromatosis gene (HFE) genotyping. Using iron phenotypes and HFE genotypes, we identified 2256 cases and 1232 controls eligible to participate in a clinical examination. To assess the potential for nonresponse bias, we compared the sociodemographic, health status, and attitudinal characteristics of participants and nonparticipants using adjusted odds ratios (ORs) and 95% confidence interval (CI).

RESULTS

Overall participation was 74% in cases and 52% in controls; in both groups, participation was highest at a health maintenance organization and lowest among those under 45 years of age (cases: OR = 0.68; 95% CI 0.53, 0.87; controls: OR = 0.59; 95% CI 0.44, 0.78). In controls only, participation was also lower among those over 65 years of age than the reference group aged 46-64 (OR = 0.64; 95% CI 0.47, 0.88). Among cases, participation was higher in HFE C282Y homozygotes (OR = 3.98; 95% CI 2.60, 6.09), H63D homozygotes (OR = 2.79; 95% CI 1.23, 6.32), and C282Y/H63D compound heterozygotes (OR = 1.82; 95% CI 1.03, 3.22) than in other genotypes, and lower among non-Caucasians and those who preferred a non-English language than in Caucasians and those who preferred English (p < 0.0001).

CONCLUSIONS

Subjects with greatest risk to have iron overload (C282Y homozygotes; cases > or =45 years; Caucasians) were more likely to participate in a postscreening clinical examination than other subjects. We detected no evidence of strong selection bias.

Ethical issues of predictive genetic testing for diabetes

With the rising number of individuals affected with diabetes and the significant health care costs of treatment, the emphasis on prevention is key to controlling the health burden of this disease. Several genetic and genomic studies have identified genetic variants associated with increased risk to diabetes. As a result, commercial testing is available to predict an individual's genetic risk. Although the clinical benefits of testing have not yet been demonstrated, it is worth considering some of the ethical implications of testing for this common chronic disease. In this article, I discuss several issues that should be considered during the translation of predictive testing for diabetes, including familial implications, improvement of risk communication, implications for behavioral change and health outcomes, the Genetic Information Nondiscrimination Act, direct-to-consumer testing, and appropriate age of testing.