[Gene technology from the viewpoint of genetic counseling]

Gentechnology detects genetic defects at the DNA level. Direct analysis, which may be performed without family investigations, is the most reliable and therefore the most desirable means of detection. Indirect analysis on the other hand-using restriction fragment length polymorphisms (RFLP) - requires family investigations and the pedigrees are not always informative; furthermore, meiotic recombination may occur leading to erroneous conclusions. Pre-symptomatic diagnosis of a severe disease may cause serious psychical and ethical problems. Prenatal diagnosis by gentechnology may be made after amniocentesis or chorionic villi sampling.