Choosing Genes for Future Children: Chapter 2 - The Science and Clinical Utilisation of Pre-Birth Genetic Testing, with Particular Focus on PGD

Abstract

It would be very unusual indeed for a person not to be aware (at least to some degree) of genetics and heredity. Phrases such as “you have your mother’s eyes” or “they’re a chip off the old block” are age-old in our society. Traits that may be inherited include physical, behavioural and medical characteristics. There is a widespread appreciation that children will inherit various features from their parents and it is this fact that forms the basis of genetic testing.The goal of this part of the report is to provide the scientific and clinical background to enable rational discussion of prebirth testing and its benefits, consequences and limitations. Other parts will discuss the legal, ethical and cultural aspects and implications of the analytical techniques outlined here.This section of the report includes an overview of genetics and the inheritance of genetic disorders and a review the current technologies used in clinical prenatal genetic testing, namely amniocentesis and chorionic villus sampling (CVS). The current extent and usage of preimplantation genetic diagnosis (PGD) internationally will be explored, followed by a summary of future technologies and the New Zealand situation. The report concludes with the current limitations of these technologies and analyses them with respect to concerns raised about positive selection and “designer” children.