When a Gene Makes You Smell Like a Fish

Advances in genetics mean that the genes behind a large number of medical conditions are being discovered. In lWhen a Gene Makes You Smell Like a Fish: ...and Other Amazing Tales about the Genes in Your Body Lisa Seachrist Chiu tells the stories of some of these.

The book starts with the story of the 'fishy' gene of the title FMO3. Chiu goes on to look at the different ways in which genes can go wrong. Some of the best known examples are recessive genes, such as that for phenylketuria, in which people can carry one defective gene without a problem, but someone with two defective copies has a problem. However, sometimes the defective gene is dominant, in which case only one copy is needed. An example of this is porphyria, which supposedly was responsible for the madness of King George III. The book goes on to describe diseases such a hemophilia, where the defective gene is on the X-chromosome, and at how one or other of the pair of genes can be turned off (known as imprinting), giving results such as the calico cat. One chapter considers how, despite the fact that most traits are the result of many genes, a single gene can still have an effect, and this is followed by a look at how the gene pool has evolved over time, caused by things such as the Black Death.

I have to say that I didn't really find that this book grabbed my interest. Chiu generally devotes just two or three pages to each gene, and a would have preferred a more extensive discussion of fewer genes. Although the book is accessible to a non-technical readership, sometimes technicalities are necessary, and I feel that if this were diluted then the book would be more readable. I think the book will mainly appeal to those readers who see this as a start and wish to learn more about some of the genes - there are plenty of references at the end of the book.