Prenatal diagnosis: molecular genetics and cytogenetics.
The technologies developed for the Human Genome Project, the recent surge of available DNA sequences resulting from it and the increasing pace of gene discoveries and characterization have all contributed to new technical platforms that have enhanced the spectrum of disorders that can be diagnosed prenatally. The importance of determining the disease-causing mutation or the informativeness of linked genetic markers before embarking upon a DNA-based prenatal diagnosis is, however, still emphasized. Different fluorescence in situ hybridization (FISH) technologies provide increased resolution for the elucidation of structural chromosome abnormalities that cannot be resolved by more conventional cytogenetic analyses, including microdeletion syndromes, cryptic or subtle duplications and translocations, complex rearrangements involving many chromosomes, and marker chromosomes. Interphase FISH and the quantitative fluorescence polymerase chain reaction are efficient tools for the rapid prenatal diagnosis of selected aneuploidies, the latter being considered to be most cost-effective if analyses are performed on a large scale. There is some debate surrounding whether this approach should be employed as an adjunct to karyotyping or whether it should be used as a stand-alone test in selected groups of women.
Bui
The-Hung
TH
Department of Molecular Medicine, Clinical Genetics Unit, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden.
Blennow
Elisabeth
E
Nordenskjöld
Magnus
M
D025063:Chromosome Disorders / Q000175:diagnosis*; D020732:Cytogenetic Analysis / Q000379:methods; D004252:DNA Mutational Analysis / Q000379:methods; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis*; D005820:Genetic Testing / Q000379:methods*; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*