How genomics is changing the practice of prenatal testing

Area of Science:

• Genetics
• Prenatal Diagnosis
• Genomic Medicine

Background:

• Genomic laboratory technologies, including microarrays and high throughput sequencing (HTS), have fundamentally changed prenatal diagnosis.
• Advances in sonography have improved fetal phenotype assessment, while non-invasive prenatal testing (NIPT) reliably identifies pregnancies at high risk for common trisomies.

Purpose of the Study:

• To provide an overview of current practices and policies in prenatal diagnosis in Switzerland.
• To discuss the impact of new genomic testing options on clinical practice and decision-making.

Main Methods:

• Review of current genomic laboratory technologies (microarrays, HTS, NIPT, CMA, WES).
• Analysis of advancements in sonographic imaging and processing.
• Discussion of screening and diagnostic options for prenatal conditions.

Main Results:

• HTS enables preconceptional comprehensive carrier screening.
• Chromosomal microarrays (CMA) offer enhanced resolution for detecting chromosomal anomalies and copy number variations (CNV).
• Gene panel or whole exome sequencing (WES) is increasingly used for follow-up of ultrasound-detected anomalies after CNV exclusion.

Conclusions:

• Invasive testing remains necessary for definitive fetal diagnosis for most conditions.
• The complexity of new genomic testing options presents challenges for informed decision-making.
• Effective communication of benefits and limitations is crucial for patients navigating prenatal genetic testing.