At the moment, the only reliable way of diagnosing chromosomal irregularities during pregnancy is to use invasive prenatal methods. This causes miscarriage in about one per cent of these risky surgical procedures.
Scientists from the Center for Prenatal Diagnosis and Human Genetics, Kudamm-199, in Berlin have been working with scientists from GATC Biotech AG and LifeCodexx AG to develop a non-invasive diagnostic test based on Next Generation Sequencing which reliably detects a fetal trisomy 21 (Down syndrome). The test is based on the sequencing of cell free fetal DNA from the maternal blood, and in the foreseeable future it could become a no-risk alternative to the invasive prenatal examinations such as the analysis of amniotic fluid (amniocentesis) which are currently used.
The pilot study involved the development of an analytical method based on the publications by Chiu et al. which was verified with more than forty clinical samples. Analyses carried out with the Illumina Genome Analyzer IIx Next Generation Sequencing system unambiguously detected all eight positive samples. The test had a sensitivity and a specificity of 100%. The results were confirmed by conventional karyotyping.