ABSTRACT
Prenatal genetic diagnosis has been feasible for over 30 years, initially based on chromosomal or enzymatic analysis for disorders such as Down’s syndrome or Tay Sachs disease, but now feasible for a wide range of Mendelian conditions using molecular techniques. Originally only possible in mid-pregnancy through amniocentesis, the development of early (10-12 weeks) chorion villus sampling has greatly reduced the delays in obtaining a result, especially in those high-risk genetic situations in which the slightly greater risk of the procedure to the pregnancy may be a less critical factor.
