The Development of an Infrastructure to Facilitate the Use of Whole Genome Sequencing for Population Health

The clinical use of genomic analysis has expanded rapidly resulting in an increased availability and utility of genomic information in clinical care. We have developed an infrastructure utilizing informatics tools and clinical processes to facilitate the use of whole genome sequencing data for population health management across the healthcare system. Our resulting framework scaled well to multiple clinical domains in both pediatric and adult care, although there were domain specific challenges that arose. Our infrastructure was complementary to existing clinical processes and well-received by care providers and patients. Informatics solutions were critical to the successful deployment and scaling of this program. Implementation of genomics at the scale of population health utilizes complicated technologies and processes that for many health systems are not supported by current information systems or in existing clinical workflows. To scale such a system requires a substantial clinical framework backed by informatics tools to facilitate the flow and management of data. Our work represents an early model that has been successful in scaling to 29 different genes with associated genetic conditions in four clinical domains. Work is ongoing to optimize informatics tools; and to identify best practices for translation to smaller healthcare systems.

Ventricular arrhythmias and sudden cardiac death caused by mitral valve prolapse: should we operate and when?

Background

Several autopsy and observational studies have investigated the link between mitral valve prolapse (MVP) and sudden cardiac death (SCD) due to the well accepted yet rare occurrence of complex ventricular arrhythmia (VA) in this cohort. Few studies however have investigated whether arrhythmia burden and more importantly SCD are reduced following surgical correction of MVP.

Purpose

To investigate the impact of mitral valve surgery (MVS) (replacement or repair) on VA and SCD in patients with MVP.

Methods

A systematic review of the current literature was conducted using an electronic search of the PubMed database in October 2021. Studies were included if subjects had undergone mitral valve (MV) repair or replacement with documented rates of arrythmias/SCD pre- and post-intervention. Small patient numbers in individual reports precluded formal meta-analysis and results were reported on a per study basis.

Results

19 identified studies (10 cohort studies, nine case studies) comprised 1322 patients with a pooled mean age of 63.4 years and 38.9% were female. 748 of the 1322 patients underwent MVS: 263 MV repair, 18 MV replacement (one with leaflet and papillary muscle excision), two MV repair with Maze procedure, 177 percutaneous transcatheter MV repair, 45 annuloplasty with or without valve repair, and in 243 cases the surgical method was not specified.

Of the 10 included cohort studies, seven of the eight which investigated rates of VA post MVS concluded there was a significant reduction, while one reported the predisposition to arrythmia persisted after relieving the abnormal mechanical effects of non-ischaemic MR (75% due to MVP). One study reported a reduction in SCD post MVS. Each of the nine included case studies showed a reduction in VA post MVS. One study showed mitral annular disjunction (MAD) was independently associated with a higher risk of arrhythmic events, this link persisting with time dependent MVS although reduced compared to medical management.

Conclusions

The underlying mechanisms for VA and SCD associated with MVP are not completely understood, and guidelines for the surgical correction of MVP based on arrhythmic and SCD risk are lacking. This systematic review illustrates a possible reduction in VA following MVS. Further identification of patients at risk of SCD, and potential use of risk stratification algorithms, would allow for consideration of earlier management and appropriate use of implantable cardioverter-defibrillators (ICD) placement / MVS with an expected survival benefit.

Funding Acknowledgement

Type of funding sources: None.

Use of the Utah population database to evaluate statewide use of genetic testing for hereditary breast/ovarian cancer

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Background: Genetic testing for hereditary breast/ovarian cancer (HBOC) continues to be underutilized, and options for population-based assessment of testing barriers and outcomes are lacking. This project uses linkages between statewide data sources available through the Utah Population Database (UPDB) to establish an infrastructure for studying the use of HBOC cancer genetic testing across a state. Methods: Clinical HBOC testing data from 1994-2018 was obtained for the University of Utah Huntsman Cancer Institute, Intermountain Healthcare, Utah Cancer Specialists, and the Salt Lake Veterans administration via electronic imports of tests attributed to these healthcare systems from three commercial laboratories. Genetic testing was linked to external data through the UPDB to determine demographic and urban/rural designation. Cancer diagnoses were obtained from the Utah Cancer Registry, and genealogies from the Utah Resource for Genetic and Epidemiology Research. These variables were matched to data available for the individual at the date of testing. For individuals with multiple genetic tests, the date for the first test was used. Results: Testing data was available for 12983 individuals who linked to additional records within the UPDB. Tested individuals were 86% White, 9% Hispanic, and 16% lived in rural/frontier areas. 75% of tests were performed between 2011-2018. 1575 (12%) had >1 pathogenic variant (PVs) identified in an HBOC gene, with the majority of PVs being in BRCA1/2 (89%), and TP53, CHEK2, and ATM each accounting for 2% of PVs. 7178 cancers were diagnosed in 5980 individuals (46%, avg. 1.2 cancer/person). Cancer cases were evaluated to determine if National Comprehensive Cancer Network (HBOC 2018) criteria were met. Cancer cases who have a relative with BC < 50 years of age or a relative with ovarian cancer (OC) were more likely to have a have BRCA1/2 PV than cases not meeting those criteria (17.5% vs 6.1% and 22.3% vs. 6.3% respectively). Cancer cases meeting criteria due to family history of pancreatic cancer also had a higher rate of PVs (13.1% vs. 8.4%) predominately due to additional PVs in BRCA2. Conclusions: This project begins to address the challenge of population assessment of HBOC genetic testing. We established a regulatory infrastructure to share testing data between multiple healthcare systems. In collaboration with commercial laboratories, genetic testing data was obtained in a consistent, discrete format even though it is stored differently within each health care system. The majority (54%) of HBOC testing in Utah is happening in people who did not have cancer at the time of their test, and focusing on assessing testing of cancer patients will not provide comprehensive information on testing done in the state. Among individuals with cancer, access to family history information is crucial for assessing the rate of PVs and utility of testing criteria.

Unanswered Questions: Hereditary breast and gynecological cancer risk assessment in transgender adolescents and young adults

Transgender (TG) individuals have higher rates of mortality associated with cancer diagnoses, in part due to avoidance of gender-assigned cancer screenings resulting in later stages at diagnosis. Knowledge about the risks of breast or gynecological cancer in TG and nonbinary (NB) persons receiving gender-affirming hormone therapy is limited. Even less information exists regarding the subset of individuals with genetic predisposition for these malignancies. We performed a retrospective literature review of studies from the last 15 years on breast cancer rates and identified risks in TG persons. An accumulating body of data on breast cancer incidence in TG persons suggests higher than previously believed rates of breast cancer in TG women compared with cisgender men and risk correlating with duration of hormone use. Few studies have examined other cancer risks in TG populations. To date, only three publications address the association with BRCA1/2 mutation presence and breast cancer incidence in TG persons. Meanwhile, there is growing awareness and social acceptance of TG/NB identities coupled with recognition of gender dysphoria at increasingly earlier ages. No information directly addressing cancer risk counseling in TG/NB adolescents and young adults with a family history of cancer or hereditary cancer syndrome exists. Whether the presence of a known genetic predisposition or strong family cancer history may affect cancer risk in these populations is unknown, leading to significant gaps in clinicians' ability to accurately and appropriately estimate cancer risks and counsel those with genetic predisposition on the risks/benefits associated with surgical options and the initiation, duration, and dosing of gender-affirming hormone therapies. A series of three cases illustrates the utility of cancer risk assessment and genetic testing in TG/NB adolescents and young adults, and the unique challenges and unanswered questions that are encountered in the process.

Clinical and laboratory findings implicating palytoxin as cause of ciguatera poisoning due to Decapterus macrosoma (mackerel)

A near fatal case of ciguatera-related intoxication following consumption of smoked Decapterus macrosoma is documented. In addition to some of the hallmark symptoms of ciguatera poisoning, the patient exhibited acute respiratory distress and severe muscle spasms. Laboratory results showed large elevations in a number of blood enzymes, indicative of muscle damage. The responsible agent was extracted from corresponding fish samples and identified as palytoxin.