New molecular methods in prenatal invasive diagnostics

Abstract

New diagnostic techniques employed in laboratories all over the world enable to create new tests for prenatal genetic diagnosis. They include cytogenetics, molecular-cytogenetics and molecular methods. Chromosomal numerical aberrations (aneuploidies) remain to be the most frequent genetic changes diagnosed prenatally. Therefore, our paper presents the latest methods used mainly in prenatal diagnosis of the most common chromosome numerical changes, as well as other methods applicable in detecting chromosome structural changes or gene mutations. One of the main advantages of these new approaches is the short period of time needed to obtain a result. Some of these techniques are used world-wide: QF-PCR (Fluorescence Quantitive Polymerase Chain Reaction) – based on the analysis of the short polymorphic sequences characteristic for each individual; MLPA (Multiplex Ligation-dependent Probe Amplification) - based on the probes ligation to complementary genomic fragments in patient DNA; microarray CGH (Comparative Genomic Hybridization) - based on genomic hybridization to microarray, which enables analysis of the entire genome. Other new methods are also gradually introduced to invasive prenatal diagnosis: NGS (Next-generation DNA sequencing) - for the analysis of the whole genome at the DNA level; BoBs (BACS-on-Beads) – molecular-cytogenetic technique based on hybridization of probes immobilized on polystyrene microspheres with fetal DNA. Nowadays, rapid diagnosis of the most common chromosomal aneuploidies is not a standard procedure in Poland, as opposed to cytogenetics (karyotyping). However, for specific clinical indications, fast and reliable methods of genetic analysis present are likely to become standard procedures in prenatal diagnosis.