The prenatal exome - a door to prenatal diagnostics?

INTRODUCTION Prenatal exome sequencing (ES) allows parents the opportunity to obtain a rapid molecular diagnosis of monogenic etiology when their fetus is found to have structural anomalies detected on prenatal ultrasound. Such information can improve antenatal and neonatal counselling, decision making and management, and expand reproductive options in subsequent pregnancies.Areas covered:This review appraises the evidence, from a comprehensive search of bibliographic databases, for the introduction of ES into the fetal medicine care pathway when investigating congenital malformations. The perspectives of clinical geneticists, clinical scientists, fetal medicine specialists and patients are explored in relation to the novel investigation and the benefits and challenges of its use in ongoing pregnancies with particular reference to UK medical practice.Expert opinion:ES provides a genetic diagnosis for more than 1 in 10 fetuses with structural differences on ultrasound and normal conventional tests (karyotype or chromosomal microarray) in carefully selected cases. The diagnostic rate increases for certain phenotypes and can range between 6 and 80% where conventional cytogenetics have not detected a diagnosis. Expert oversight is required to ensure that patients receive high quality, evidence-based care and accurate counselling, supported by a multidisciplinary team familiar with the test and its implications.