Cost-effectiveness frameworks for comparing genome and exome sequencing versus conventional diagnostic pathways: A scoping review and recommended methods

Implementation of a National Prenatal Exome Sequencing Service in England: Cost-Effectiveness Analysis

OBJECTIVE

Prenatal exome sequencing (pES) for diagnosing fetal structural anomalies commenced in the English National Health Service (NHS) in 2020. We evaluated cost-effectiveness to the healthcare system, and costs to families, of pES in addition to standard testing, compared to standard testing alone.

DESIGN

A cost-effectiveness analysis combining costs, outcomes, parent and professional interview and professional survey data.

SETTING

The English NHS Genomic Medicine Service.

SAMPLE

413 families with fetal anomalies with a suspected genetic cause referred for pES from 01 October 2021 to 30 June 2022.

METHODS

We costed the incremental resource required to deliver the pES clinical pathway. We calculated the diagnostic yield (proportion of cases with pathogenic variants). We divided the total incremental cost by the number of cases with a diagnosis to calculate cost-effectiveness. We estimated the annual NHS budget requirement based on case numbers. We determined parental costs from interviews.

MAIN OUTCOME MEASURES

Incremental costs of pES to the NHS and families, incremental cost per additional diagnosis and NHS budget impact.

RESULTS

Of 413 referred cases, 241 were tested, at a cost of £2331 (95% credibility interval £1894-£2856) per referred case or £3592 (£2959-£4250) per case that proceeded with testing. The incremental cost per diagnosis (yield 35.3%) was £11 326 (£8582-£15 361). Based on referrals data 01 October 2022 to 30 September 2023, pES costs the NHS £1.8 m annually. Family costs could not be separated from other pregnancy-related appointments but were not considered burdensome; most appointments were concurrent or remote.

CONCLUSION

pES costs the English NHS £11 326 for each additional diagnosis. Incremental costs to families are negligible.

Exome sequencing of 18,994 ethnically diverse patients with suspected rare Mendelian disorders

We investigated the effectiveness of exome sequencing (ES) in diagnosing ethnically diverse patients with rare genetic disorders. A total of 18,994 patients referred to a single reference laboratory for ES between 2020 and 2022 were studied for the diagnostic rate and factors influencing the diagnostic rate. The overall diagnostic rate was 31.8%. Dermatological disorders, skeletal disorders, and neurodevelopmental disorders disease categories, early age-of-onset, presence of consanguinity, and the presence of parental sequencing data were found to be correlated with a higher diagnostic rate. Nearly 68K variants were identified in our dataset at a higher frequency than that observed in gnomAD 4.0. Of these, 507 variants could be classified as likely benign, representing 0.04% of non-benign variants in ClinVar (507/1,433,904) and 0.20% of the non-benign ClinVar variants observed at least once in our cohort (507/276,777). The overall diagnostic rate is comparable to that observed in other large cohort studies with less diverse ethnic backgrounds.

Impact of prenatal genomics on clinical genetics practice

Genetic testing for prenatal diagnosis in the pre-genomic era primarily focused on detecting common fetal aneuploidies, using methods that combine maternal factors and imaging findings. The genomic era, ushered in by the emergence of new technologies like chromosomal microarray analysis and next-generation sequencing, has transformed prenatal diagnosis. These new tools enable screening and testing for a broad spectrum of genetic conditions, from chromosomal to monogenic disorders, and significantly enhance diagnostic precision and efficacy. This chapter reviews the transition from traditional karyotyping to comprehensive sequencing-based genomic analyses. We discuss both the clinical utility and the challenges of integrating prenatal exome and genome sequencing into prenatal care and underscore the need for ethical frameworks, improved prenatal phenotypic characterization, and global collaboration to further advance the field.

Cost-effectiveness of exome sequencing and chromosomal microarray for low-risk pregnancies

BACKGROUND

Chromosomal microarray analysis (CMA) has been central to prenatal genetic diagnosis, detecting copy number variants with a ∼1% yield in low-risk cases. Next-generation sequencing (NGS), including exome sequencing (ES), enhances diagnostic capabilities with higher yields (8.5-10%) but at greater cost and complexity. While ES's cost-effectiveness is studied in high-risk pregnancies, data for low-risk pregnancies remain lacking. This study evaluates the cost-effectiveness of ES in low-risk pregnancies.

OBJECTIVE

This study aimed to investigate the cost-effectiveness of exome sequencing compared with chromosomal microarray analysis.

STUDY DESIGN

Costs, utilities, and quality-adjusted life years were modeled for prenatal testing with chromosomal microarray analysis or chromosomal microarray analysis + exome sequencing. Average costs and utilities were discounted at 3%. In addition, 2 strategies for screening were compared using the Markovian decision analysis model: (1) chromosomal microarray analysis only (an abnormal result leads to a termination of pregnancy, and a normal test has a 1 to 160 chance of developing into a severe disorder) and (2) exome sequencing after a normal chromosomal microarray analysis (a positive result leads to a termination of pregnancy). Of note, 1-way sensitivity analysis was performed for all variables. The outcome measures included quality-adjusted life years after abortion, costs of chromosomal microarray analysis and exome sequencing, and health expenses of a critically ill infant. The time horizon of the model was 20 years.

RESULTS

The total costs were $1348 for chromosomal microarray analysis and $3108 for chromosomal microarray analysis + exome sequencing. The quality-adjusted life years with a time horizon of 20 years were 14.15 for chromosomal microarray analysis and 14.19 for chromosomal microarray analysis + exome sequencing, with an incremental cost-effectiveness ratio of $46,383 per quality-adjusted life years. Sensitivity analysis revealed that the time horizon and the disutility of moderate/severe disability of the genetic disorder have an effect on the incremental cost-effectiveness ratio. For example, the incremental cost-effectiveness ratios are $84,291 per quality-adjusted life years for a relatively small disutility of moderate/severe disability and $94,148 per quality-adjusted life years for a shorter time horizon of 10 years.

CONCLUSION

Exome sequencing has the potential to be cost-effective compared with chromosomal microarray analysis alone. Our research provides data regarding the cost-effectiveness of exome sequencing without a specific indication, which will become increasingly important in the near future as whole exome sequencing becomes the first-tier test in prenatal diagnosis.

High-throughput omics technologies in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing intestinal disease. Elucidation of the pathogenic mechanisms of IBD requires high-throughput technologies (HTTs) to effectively obtain and analyze large amounts of data. Recently, HTTs have been widely used in IBD, including genomics, transcriptomics, proteomics, microbiomics, metabolomics and single-cell sequencing. When combined with endoscopy, the application of these technologies can provide an in-depth understanding on the alterations of intestinal microbe diversity and abundance, the abnormalities of signaling pathway-mediated immune responses and functionality, and the evaluation of therapeutic effects, improving the accuracy of early diagnosis and treatment of IBD. This review comprehensively summarizes the development and advancement of HTTs, and also highlights the challenges and future directions of these technologies in IBD research. Although HTTs have made striking breakthrough in IBD, more standardized methods and large-scale dataset processing are still needed to achieve the goal of personalized medicine.

Outcomes and Associated Extracardiac Malformations in Neonates from Colombia with Severe Congenital Heart Disease

Congenital heart disease (CHD) is a common structural anomaly, affecting ~ 1% of live births worldwide. Advancements in medical and surgical management have significantly improved survival for children with CHD, however, extracardiac malformations (ECM) continue to be a significant cause of morbidity and mortality. Despite clinical significance, there is limited literature available on ECM in neonates with CHD, especially from Latin America. A cross-sectional study of neonates with severe CHD evaluated by the medical-surgical board team at Fundación Cardiovascular de Colombia from 2014 to 2019 was completed to characterize morbidity, mortality, surgical outcomes, and ECM. Demographics and surgical outcomes were compared between neonates with and without ECM. Medical record data were abstracted and descriptive statistical analysis was performed. Of 378 neonates with CHD, 262 had isolated CHD (69.3%) and 116 had ECM (30.7%). The most common ECM was gastrointestinal (n = 18, 15.5%) followed by central nervous system (n = 14, 12%). Most neonates required a biventricular surgical approach (n = 220, 58.2%). Genetic testing was performed more often for neonates with ECM (n = 65, 56%) than neonates with isolated CHD (n = 14, 5.3%). Neonates with ECM had lower birth weight, longer hospital stays, and higher postsurgical complications rates. There was no difference in survival between groups. Overall, Screening for ECM in neonates with CHD is important and identification of ECM can guide clinical decision-making. These findings have important implications for pediatric healthcare providers, especially in low- and middle-income countries, where the burden of CHD is high and resources for managing CHD and extracardiac malformations may be limited.

The evolution of cancer genomic medicine in Japan and the role of the National Cancer Center Japan

The journey to implement cancer genomic medicine (CGM) in oncology practice began in the 1980s, which is considered the dawn of genetic and genomic cancer research. At the time, a variety of activating oncogenic alterations and their functional significance were unveiled in cancer cells, which led to the development of molecular targeted therapies in the 2000s and beyond. Although CGM is still a relatively new discipline and it is difficult to predict to what extent CGM will benefit the diverse pool of cancer patients, the National Cancer Center (NCC) of Japan has already contributed considerably to CGM advancement for the conquest of cancer. Looking back at these past achievements of the NCC, we predict that the future of CGM will involve the following: 1) A biobank of paired cancerous and non-cancerous tissues and cells from various cancer types and stages will be developed. The quantity and quality of these samples will be compatible with omics analyses. All biobank samples will be linked to longitudinal clinical information. 2) New technologies, such as whole-genome sequencing and artificial intelligence, will be introduced and new bioresources for functional and pharmacologic analyses (e.g., a patient-derived xenograft library) will be systematically deployed. 3) Fast and bidirectional translational research (bench-to-bedside and bedside-to-bench) performed by basic researchers and clinical investigators, preferably working alongside each other at the same institution, will be implemented; 4) Close collaborations between academia, industry, regulatory bodies, and funding agencies will be established. 5) There will be an investment in the other branch of CGM, personalized preventive medicine, based on the individual's genetic predisposition to cancer.