Statistics from Altmetric.com
Preimplantation genetic diagnosis (PGD) was first carried out at the Hammersmith Hospital in London by Robert Winston and Alan Handyside, who developed a way of determining the sex of the human embryo before implantation, thereby reducing the risk of X linked disease. PGD is yet another example of a technological advance that originated in the UK but because of lack of resources and investment has been extensively taken up and developed elsewhere in Europe and particularly in the USA. As the authors of this Atlas state, in the ensuing 10 years, as many as 40 PGD centres have been established, in 17 countries; to date these centres have performed approximately 2000 clinical IVF cycles for PGD resulting in nearly 500 pregnancies. More than two thirds of these cycles were performed in the USA; the largest number (almost 1000) was contributed by the Reproductive Genetics Institute, Chicago, to which the authors belong.
The Atlas is technically detailed and beautifully illustrated. It consists of two sections; the first is entitled “A Review of Methods and Experience in PGD”, the second is “PGD Illustrated”. The written text is brief, consisting of 50 pages, but as befits an atlas the second section extends over 100 pages. The early part covers normal and abnormal preimplantation development, from oocyte maturation onwards. This part is particularly revealing and useful for the reader with a genetic rather than an embryological background. Next is the chapter on micromanipulation and biopsy of polar bodies and single blastomeres from cleavage stage embryos. Step by step instructions are given for making the necessary tools for polar body removal, although only one other centre besides their own uses polar bodies for PGD. Similarly, the following chapter on nuclear transfer techniques for visualisation of chromosomes in polar bodies and blastomeres describes esoteric technology that is not carried out in any other centre and is of limited clinical use, although it has many research applications. There follow the two chapters that cover the Chicago group's approaches to chromosome analysis by FISH and single cell DNA analysis for the detection of dominant and recessive disorders.
The atlas is described as “An illustrated textbook and reference for clinicians”. It will best fulfil that role, since it is of limited use to either the embryologist or geneticist already working in the growing field of PGD. It will enable the clinician to understand better the complexity of the task facing the laboratory professionals when a patient is referred for genetic diagnosis before the embryo implants.