1. Mosaicism-overview Chromosome mosaicism, the existence of two cell lines with differing chromosomal constitutions derived from a single fertilization, may be observed in amniotic fluid (AF) or chorionic villus (CVS) samples at prenatal diagnosis or in blood or skin samples of individuals referred for a variety of medical conditions. The diagnosis of mosaicism, particularly when […]
In the 1980s, the development of in situ hybridization techniques, particularly those utilizing fluorescent markers (FISH) (see Article 22, FISH, Volume 1) (Pinkel et al., 1988), led to the discovery of the first cryptic deletion syndromes, that is, those in which the missing material was not visible using conventional microscopy. Discovery of most microdeletion syndromes […]