BOOK REVIEWS 567 Prenatal Diagnosis and Selective Abortion. By H. HARRIS. London: Nuffield Provincial Hospitals Trust, 1974. Pp. 101. 11.75. U.S. publisher, Harvard University Press. The recent introduction of prenatal detection of genetic disorders has raised a variety of ethical and biological questions. This book not only reviews a number of problems with intrauterine diagnosis, including the scope of the procedure and its effects on the incidence of genetic diseases, but it also raises a number of ethical questions which have generated considerable discussion in both professional and nonprofessional fields. The text is authored by an acknowledged expert in the field of human genetics. Harris has divided his thesis into three major chapters. The first presents an overview of the present state of knowledge of intrauterine diagnosis as it relates to chromosomal abnor- malities, X-linked disorders, metabolic diseases, and congenital malformations. This section does not contain an extensive review of the literature but does highlight many of the more important aspects. The second section deals with effects on the incidence of genetic disease. It outlines both the potential short- and long-term effects that are expected to follow from selective abortion whether the abnormality is a single gene or classical Mendelian condition, a gross chromosomal defect, or a disorder regarded as multifactorial in origin. The last section, which is the most interesting in my opinion, deals with the question of ethics. Harris not only clearly points out the ethical and moral questions of selective abortion, including the undesirable aspects, but he also describes the visible benefits which, in his opinion, make intrauterine detection a valuable advance in medicine. The book is well written, easy to read, and reflects Harris's wide experience in the field of human genetics. The second and third chapters are especially clear, and the argu- ments presented are easily followed. While little in the book can be considered new or original, since many of the comments and observations have been discussed in numerous recent reviews, the style and clarity should make this book a valuable contribution to the field. The book should form a good introduction to the scope and problems of antenatal diagnosis for students in biology, genetics, and ethics. HENRY L. NADLER Children's Memorial Hospital Chicago, Illinois Heritable Disorders of Amino Acid Metabolism: Patterns of Clinical Expression and Genetic Variation. Edited by W. L. NYHAN. New York: John Wiley & Sons, 1974. Pp. 765. $39.00. This 765-page textbook represents the latest of several recently published texts con- cerned with methods of diagnosis, treatment, and biochemical insight into human meta- bolic pathways offered by studies of the inborn errors of aminoacid metabolism (cf. Duncan's Diseases of Metabolism edited by P. K. Bondy and L. E. Rosenberg, 7th ed., 1974; The Metabolic Basis of Inherited Disease edited by J. B. Stanbury, J. B. Wyn- gaarden, and D. S. Fredrickson, 3d ed., 1972; Amino Acid Metabolism and Its Disorders by C. R. Scriver and L. E. Rosenberg, 1973; and Laboratory Techniques for the Detec- tion of Hereditary Metabolic Disorders by V. E. Shih, 1973). The book contains 33 568 BOOK REVIEWS chapters from 38 contributors. It is subdivided into 11 parts: an introduction by Nyhan; disorders of branched chain amino and organic acid metabolic pathways; phenylketonuria, tyrosinemia, and albinism; histidinemia and carnosinemia; glycinemia and prolinemia; urea cycle defects and lysinemia; sulfur-containing aminoacidopathies; pyroglutamic acidemia; transport defects; nutrition and growth; and methods for screening and investi- gating inborn errors of aminoacid metabolism. The choice of authors for these sections reflects a clear emphasis on practical clinical diagnosis and care. They are pediatricians or clinical biochemists whose practical experience lends an authoritativeness to each chapter. Because newborn screening for inborn errors of metabolism is now mandated in most states, and with the advent of gas chromatography linked with mass spectrometry, this new group of individually rare but collectively important disorders demands broader participation by the community of health care professionals. This text provides a practi- cal resource for these individuals. It has detailed clinical descriptions of patients affected by disorders of aminoacid metabolism, including quantitative values for specific metabo- lites contained in normal and abnormal physiologic fluids. Most chapters are arranged like a traditional clinical textbook with a brief historical review of the given disorder, a description of the phenotype, a discussion of the biochemical pathways involved, a statement of the pathology where indicated, and a description of diagnostic methods including enzyme assays of various tissues. Perhaps the most unique aspect is the inclu- sion of detailed descriptions of diets and therapy where applicable. Many chapters contain specific tables listing model diets with specific aminoacids, lipids, carbohydrates, minerals, and vitamins in table form. The less common disorders which as yet are not clearly defined with respect to diagnosis, mechanism, or treatment are not neglected. There is an excellent review of uncommon disorders of sulfur aminoacid metabolism by J. C. Crawhall and of pyroglutamic acidemia by L. Eldjarn and colleagues. The chapter on aminoacid transport in kidney by C. R. Scriver and M. Bergeron represents a scholarly culmination of several chapters on this subject by these authors which have appeared previously. A chapter by S. Synderman on aminoacid requirements in the infant and that by L. Schmidt on biochemical detection of metabolic disease place the finishing touches on this practical textbook. A few criticisms can be brought to bear, however. The authoritative emphasis on clinical aspects of disease expression, pathogenesis, and treatment produces an optimistic aura of completeness which is not yet warranted. This aura may beguile the reader who is not intimately involved in this field into believing that the facts are all available. Thus, the tabulation of a defect in leucine-isoleucine transamination or the statement that defec- tive electron transfer systems produce sarcosinemia when sarcosine dehydrogenase assays are normal are neither supported by objective evidence or followed by statements of healthy skepticism. The emphasis on diagnosis of metabolic disorders through detection of accumulated precursors in blocked metabolic pathways tends to distract the reader from concern over the primary genetic defect-the proteins (enzymes) involved in these blocked metabolic pathways. Such an emphasis does not lend itself to future research and treatment such as enzyme replacement and genetic engineering. The chapter on homo- cystinuria by T. L. Perry followed by a discussion of selected aspects of enzymes and metabolism related to homocystine metabolism by S. H. Mudd represents a good com- promise between clinical and investigative interests and an example which, if followed in other sections, would have supported the overall textbook. In summary, this book pro- BOOK REVIEWS 569 vides a timely compilation for the diagnosis and treatment of inborn errors of aminoacid metabolism and deserves a place on the shelf with the previous texts on this subject. Louis J. ELSAS, II Emory University Atlanta Georgia The Genetic Structure of Populations. By A. JACQUARD. Translated by D. and B. CHARLESWORTH. Biomathematics, vol. 5. New York: Springer-Verlag, 1974. Pp. 569. $39.40. This book is an English translation of Jacquard's earlier French work Structures genetiques des populations, but it includes a number of new chapters and sections. It is concerned mainly with mathematical theories of population genetics with emphasis on man, though in the last chapter some data analyses are presented. The main topics dis- cussed are random mating populations, inbreeding and assortative mating, some quantita- tive genetics, natural selection, migration, and genetic distance. There are appendixes on difference equations and matrix algebra. Compared with Crow and Kimura's book on the same subject, An Introduction to Population Genetics Theory, the material covered is not so wide ranging. But some topics such as overlapping generations and genetic distance are discussed more extensively than in any other current book. The mathematics used is not very sophisticated. Nearly half of this book is devoted to the theory of inbreeding. Jacquard's treatment of this subject differs somewhat from that of most other textbooks and includes a great deal of mathematical detail and formality. In order to explain the effect of inbreeding he introduces three different concepts of genetic structure which are not really required: genotypic structure, genotypic probability structure, and probability structure of an individual. In the study of relatedness of individuals he considers 15 different types of gene identity between two individuals, which are later condensed into nine cases. The explanation of these identity measures is clear, but because of the recognition of so many different cases, his treatment of this subject becomes very complicated. If we note that Cotterman's k statistics (three cases) are sufficient for most practical purposes, I wonder whether it is worth the extensive discussion. Jacquard also devotes considerable space to a study of the frequencies of consanguine- ous marriages expected under