I must admit that when I first volunteered to review Consanguinity in Context, I had confused consanguinity with ex-sanguinity. Expecting a book about porphyria, rabies, and other possible sources of vampire myths, I was quite surprised to instead start reading about inbreeding. However, far from being disappointed, I found Alan Bittles’ book to be extremely fascinating. Bittles provides an eye-opening and exhaustive review of the political, religious, economic, social, and biological factors impinging on consanguineous unions. His goal for this work is well summarized at the end of chapter one: “… to provide an appropriately extensive framework of information within which the subject [of consanguineous unions] can be rationally and dispassionately evaluated.” Consanguinity in Context admirably fulfills this objective.
Bittles’ book can be roughly divided into four parts. First, he discusses how people around the world feel about consanguineous unions, moving smoothly from historical examples to present-day prejudices. Next, he describes why inbreeding can evoke such strong emotional responses in people by describing the religious, legislative, and early medical edicts that have condoned or condemned marriage between relatives. The bulk of the text looks at the genetic and biological ramifications of consanguineous unions, focusing on first-cousin marriages, for which the most data is available. Finally, Bittles ends the book with a number of concrete recommendations for moving forward, both in terms of legislation as well as how genetic counseling services can be better tailored to specific societies.
In keeping with the historical perspective throughout Consanguinity in Context, there are myriad details in the book, particularly in the first two sections. However, periodic references back to previous material keep the reader grounded. Further, Bittles has the rare ability to elevate historical analysis to an intriguing account of personal lives and how they motivate national actions. In addition, the author has a wry sense of humor, and small jokes are scattered through the text like gifts for the attentive reader.
An overarching theme of Consanguinity in Context is the lack of properly performed medical studies on consanguineous unions. The genetics and biology section begins with a discussion of population genetics in general, laying out the difficulties associated with studying the effects of inbreeding and well as the criteria that should be met for a scientific study to be reliable. Numerous studies are then summarized that analyze the relationship between consanguineous marriages and, among other metrics, birth defects, infant and child mortality, and adult diseases. Few of these studies meet Bittles’ standards, however, further supporting his claims that additional analyses must be conducted. In fact, a secondary goal of the book seems to be prompting fledgling geneticists to address this informational gap. So go! Perform these studies! But please use appropriate multivariate analysis.