Expert Review 02
Detecting mosaicism with QF-PCR by Dr Kathy Mann
Mosaicism in prenatal samples is a complex but important phenomenon. Optimal use of QF-PCR will identify most clinically significant cases of mosaicism, and also provide additional information regarding the origin of the abnormal cell line.
Authored by Dr. Kathy Mann, pioneer in prenatal QF-PCR analysis, it includes useful sections on: assay design, sample processing, limitations and much more.
What you'll learn
- Origin of mosaicism
- Significant benefits of the genotyping aspect of QF-PCR
- Why the use of dissociated cells is now recommended as part of UK best practice
- How optimal use of QF-PCR will identify most clinically significant cases of mosaicism and more
Mosaicism was first described by Curt Stern in the 1930s and denotes the presence of two or more populations of cells with different genotypes that have developed from a single fertilised egg. This phenomenon is a widely recognised complication of prenatal diagnosis with between 1 and 2% of prenatal karyotypes found to be mosaic (ACC Working Party, 1994), usually manifesting as the presence of normal and aneuploid cell lines with an individual-specific distribution within the placenta and/or fetus. Although mosaicism is confined to the placenta in more than 80% of cases, it is important to identify the presence of both cell lines; either or both cell lines may be present in the fetus, modifying phenotype expression, whilst an abnormal cell line confined to the placenta may result in placental insufficiency and growth restriction in the fetus.