Genomic Testing for Prenatal Clinical Evaluation of Congenital Anomalies

Abstract

Congenital anomalies occur in about 2-3% of liveborn and 20% of stillborn infants. They constitute a serious public health and epidemiological problem. The etiology of congenital anomalies is complex; they can result from genetic factors, environmental factors, or a combination of both. It is estimated that genetic factors represent an important cause of congenital anomalies and may be due to different genetic mechanisms: aneuploidies, deletions and duplications of DNA segments, and single gene disorders. Due to the genetic complexity, the targeted prenatal genetic diagnostics of congenital anomalies is usually problematic and challenging. In recent years new diagnostic algorithms for prenatal genetic testing are being developed with the advent of new genomic technologies, like molecular karyotyping and next-generation sequencing. These technologies offer testing options that exceed conventional karyotyping and targeted molecular genetic testing with better diagnostic yield. In this chapter, an overview of the conventional genetic diagnostic approach and the use of new genomic technologies in the diagnostic algorithm of prenatally detected congenital anomalies are discussed.