Noninvasive prenatal diagnosis using ccffDNA in maternal blood: state of the art.

Owing to the risk of fetal loss associated with prenatal diagnostic procedures, the last decade has seen great developments in noninvasive prenatal diagnosis (NIPD). The discovery of circulating cell-free fetal DNA (ccffDNA) in maternal plasma has opened new lines of research in alternative technologies that may facilitate safe diagnosis. Because ccffDNA represents only a small fraction of all DNA present in maternal plasma and it is masked by the background of maternal DNA, the scope of NIPD was, until recently, limited to the study of paternal DNA sequences (i.e., detection of SRY sequences, RhD gene in RhD-negative women and paternally inherited single-gene disorders, such as cystic fibrosis and Huntington's disease). However, new discoveries and technology are making NIPD a real option for patients and providing for an array of clinical applications, such as molecular studies in high-risk families, general screening and pregnancy management.