Whole exome sequencing (WES) and Whole genome sequencing (WGS) have been increasingly adopted as the primary prenatal genetic diagnostic strategy due to the higher diagnostic yield and cost-effectiveness, offering a flexible option to analyse the whole genome leading to higher detection rates than were previously attainable.
The greater diagnostic yield of WES and WGS greatly benefits fetal outcomes for all parents and clinicians but it uniquely benefits ethnic minority groups as the screening allows for the detection of significant variants which were not being analysed by the previously commonly used targeted panels. For example, a panel that detects the 23 most common CFTR pathogenic variants fails to identify nearly three-quarters of affected pregnancies in Hispanic persons compared to full sequencing of the gene with deletion and duplication analysis (Shum, 2021).
Whole Exome Sequencing
Whole-exome sequencing (WES), which captures the ‘protein-encoding’ regions (exons) of the DNA offers broader possibilities to evaluate foetus with structural anomalies, improving the delineation of the prognosis, yield and accuracy of diagnoses, providing better clinical utility and allowing better options for genetic counselling for parents (Kilby, 2021). In addition, it is also possible that the identification of prenatal pathological variants associated with structural anomalies might facilitate opportunities for antenatal therapies in some cases (e.g. mesenchymal stem cell transplantation).
egSEQ Exome Panels are specially optimised to capture CDS regions comprehensively with market-leading effective coverage of up to 99.88%, offering customers highly customisable and cost-effective whole Exome solutions for prenatal testing.
Whole Genome Sequencing
Whole Genome Sequencing (WGS) detects the complete genome sequence at one time and provides the most comprehensive collection of an individual’s genetic variation based on the human reference genome. The DNA library is whole genome sequenced (WGS) at a chosen depth based on cost, throughput and data output requirements
With egSEQ library prep solutions, Edinburgh Genetics offers healthcare providers and clinicians offering NGS solutions with market-leading capability in prenatal testing.
Kilby, M. D. (2021) ‘The role of next-generation sequencing in the investigation of ultrasound-identified fetal structural anomalies’, BJOG: An International Journal of Obstetrics and Gynaecology, 128(2), pp. 420–429.
Shum, B. O., Bennett, G., Navilebasappa, A., & Kumar, R. K. (2021). Racially equitable diagnosis of cystic fibrosis using next-generation DNA sequencing: a case report. BMC pediatrics, 21(1), 1-5.