Prenatal genetic testing 2: diagnostic tests

Prenatal genetic testing can be divided into two categories: screening and diagnosis. Prenatal genetic screening tests are used to assess carrier status or as a fetal risk assessment for a particular genetic disorder [1]. Prenatal genetic diagnostic testing is used to diagnose particular genetic conditions with as much certainty as possible [1,2]. This review will focus on the diagnostic side of prenatal genetic testing.

Next generation sequencing (NGS) has revolutionized prenatal genetic diagnostic testing. NGS methods are becoming more advanced and accurate as more genetic information is being linked to genetic conditions.

Prenatal genetic diagnostic testing involves clinicians invasively obtaining tissue via amniocentesis or chorionic villus sampling to identify if a fetus has a genetic condition. This testing has traditionally been done through fluorescence in-situ hybridization, karyotype, or chromosomal microarray analysis. However, genetic testing is in a time of rapid technologic expansion and new methods like NGS, which includes targeted gene panels, whole exome sequencing, and whole genome sequencing are being used too. In this time of growth, it is important that providers educate themselves on the research support and indication behind each type of genetic diagnostic test.