Book reviews Journal of Medical Genetics, 1979, 16, 238-244 Medical Genetic Studies of the Amish. Selected Papers By V. A. McKusick. (Pp. x + 525; Figures + Tables. £19-25.) Baltimore and London: Johns Hopkins University Press. 1978. To read this edited collection of papers is both a fascinating experience and, for one already familiar with the Amish, a pleasurable reminder of the persistence and success of their remarkable way of life in 20th century America. A visitor to the Moore Clinic at Johns Hopkins Hospital in the late 1960s might have been excused if he had thought that the Amish formed a majority of the Baltimore popula- tion, but this book shows clearly how worthwhile the intensive study of this group has proved in both medical and population genetics. The papers are reproduced unchanged, but their value is greatly increased by the addition of notes on subsequent developments. They are grouped into those dealing with general and population genetics, studies of previously recognised Mendelian syn- dromes, and (the largest section) 'new recessively inherited entities, many of which would have been difficult, if not impossible, to recognise outside the setting of a defined, closed, and well documented community as provided by the Amish'. Among these delineations of new disorders, that of 'cartilage hair hypoplasia' still stands out for its clarity and its masterly combination of clinical and genetic information. The value of the studies in this book extends far beyond the demonstration that the disorders in question are recessively inherited. The range of clinical expression produced by what clearly must be a single gene is something that is difficult to document in the more heterogeneous patients seen in most populations. The studies of autosomal recessive limb-girdle muscular dystrophy and of the 'Troyer syndrome' provide excellent examples of this. Another particularly impressive feature of the Amish studies is the detail and accuracy of the genealogical and demographic work which underlies them, much of it due to the attachment of Amish people themselves to this type of documentation. It is of interest that a number of the main contributors to the book are themselves of Amish origin, and it is fortunate that the Amish antipathy to further education has not prevented the emergence of those individuals to transmit the unique aspects of Amish culture to the world in general. Anyone working in medical genetics to whom the Amish are unfamiliar should read this book without delay; it will be a revelation as to the value of studying genetic isolates. Those who do know of the Amish will not need encouragement to refresh their memory of the subject and gain new ideas. It should also serve as a stimulus for people to study their own equivalents of the Amish. Though few of us have access to such an ideal population, there are many minority groups which would repay much closer investigation, where studies of genetic diseases have not been attempted. Many of these groups, less robust than the Amish, may soon disappear for ever if the opportunity is not taken soon. P. S. HARPER British Medical Bulletin: The HLA System Vol. 34, No. 3, September 1978. Scientific Editor, W. F. Bodmer. (Figures + Tables. £5O00.) London: The British Council. 1978. Medical journals are now replete with articles on HLA and, though weary voices have been heard to exclaim 'not HLA again', we should take heart. Cytogenetics had similarly inauspicious beginnings when, 20 years ago, pictures of 'squashed spiders' began to appear in medical journals. There are many aspects of HLA which are relatively simple, though others seem comprehensible only to experienced travellers in the exotic lands of lymphomania. The latest issue of the British Medical Bulletin provides an excellent overview of the HLA system and will do much to enlighten the weary. It is a convenient introductory package for this fascinating genetic system. I recommend reading 'Evolution and Function of the HLA System' at an early stage as, in it, central issues relating to the system are dealt with succinctly and comprehensibly. The other articles can be divided into several categories. Firstly, the 'technology' of HLA: serology, cellular typing, the chemistry of HLA antigens, and the 'new' HLA- DRW locus are considered in 4 articles. Secondly, the role of HLA as part of the major histocom- patibility system (MHS) is discussed in 2 articles devoted to complement genetics and to the immune response. Thirdly, the somewhat variable importance of HLA in human organ transplantation is described objectively. The fourth category, that of the associa- tion between HLA and various diseases, takes up a large part of the Bulletin in a total of 8 papers 238 o n A p ril 5 , 2 0 2 1 b y g u e st. P ro te cte d b y co p yrig h t. h ttp ://jm g .b m j.co m / J M e d G e n e t: first p u b lish e d a s 1 0 .1 1 3 6 /jm g .1 6 .3 .2 3 8 -a o n 1 Ju n e 1 9 7 9 . D o w n lo a d e d fro m http://jmg.bmj.com/ reviewing arthropathies, multiple sclerosis, diabetes whole, as a few examples will show. Single immuno- mellitus, coeliac disease, liver disease, acute leuk- globulin polypeptides are coded for by two or more aemia and Hodgkin's disease, and finally tropho- genes; families of multiple closely linked genes are blastic tumours. Unfortunately, the genetic linkage characteristic of immunology, but may well be a between HLA and 21-hydroxylase deficiency was basic phenomenon of mammalian germ lines; discovered too late for inclusion in the Bulletin. immunoglobulins demonstrate the importance of 21-hydroxylase deficiency is a paradigm of genetic somatic mutations; the interaction between different disease as the genetics, biochemistry, and treatment lymphocyte types exerts control over protein syn- are so well worked out. Never before have we had thesis, presumably by some form of genetic feedback. such razor-sharp dissection of a segment of a human Last, but not least, allelic exclusion (involving auto- chromosome and been able to discern, even if we do somes) was discovered in a study of antibody not always fully understand, the interactions of molecules. closely linked genes, the effects of linkage disequili- Fudenberg's book covers all these areas with great brium, and the emergence of disease associations. clarity, tackling with skill a plethora of experimental Without doubt, HLA will be of the greatest practical data from both comparative and human studies. An importance in the prediction of those at risk of abundance of tables and diagrams is a particularly developing many diseases with a clear genetic basis praiseworthy feature of the book. As in the first but which depend on environmental triggers. As our edition, chapter 1 is an introductory essay which is understanding of this system increases, we will be well worth reading. Chapter 2 describes immuno- able to detect and potentially remove offending globulin structure and evolution and goes on to a environmental agents thus allowing true prevention. lucid exposition of the admittedly complicated This issue of the British Medical Bulletin is first genetics of immunoglobulin molecules. Chapter 4 rate and is obligatory reading for every clinical tackles the generation of antibody variability and geneticist. It is remarkable value at £5-00 and is describes what is known of the genetics of antibody perfectly complementary to 'Basic Immunogenetics' specificity. Chapter 5 deals succinctly with lymphoid by Fudenberg and his colleagues which is reviewed membrane antigens including their genetic control below. and relation to immune response, T and B cells, and R. HARRIS lymphocyte interactions. The potted version of mouse H-2 is excellent. Chapter 6 is an adequate Basic Immunogenetics review of the human blood group systems and the 2nd Edition. By H. H. Fudenberg, J. R. L. Pink, book finishes, as before, with a number of useful An-Chuan Wang, and S. D. Douglas. appendices. (Pp. ix + 262; Figures + Tables. £3*95.) The index is generally good, though there are New York and Oxford: Oxford University Press. occasional omissions. For example, I encountered 1978. 'Fd' in the text but could not find an entry in the index or in the appendices. This edition went to press Since the first edition was published in 1972, a great before the Seventh International Histocompatibility deal has happened in the field of immunogenetics Workshop and before most of the new information and it is remarkable that Dr Fudenberg and his on HLA-DW and -DRW loci became available. colleagues have managed to limit the expansion of (This gap is filled admirably by 'The HLA System' the second edition to only 48 pages. The use of finer in No. 3 of Vol. 34 of the British Medical Bulletin quality paper has also kept the overall dimensions which should be read in parallel with this book and of the book about the same. One has to confess at is reviewed above.) The section on HLAwill no doubt the outset that immunogenetics is difficult. I wonder, be extended in a third edition. These criticisms do not for example, howmany immunochemists feel at home detract significantly from 'Basic Immunogenetics' in the new and rapidly expanding sister-field of cell which remains an essential for the libary of gene- immunology? Taken together, the subject matter of ticists of all persuasions, both graduate and under- this book, which covers the chemistry and genetics graduate. of antibody molecules, cell mediated immunology, R. HARRIS and human blood group serology, is a highly concentrated collection of facts and theories. One The Genetics of Agig should not, however, succumb to the temptation of Edited by E. L. Schneider. (Pp. xvi + 424; leaving immunogenetics to the experts in the hope Figures + Tables. $39-00.) New York and that it will become easier as time goes by, for already London: Plenum Press. 1978. the subject has produced a number of unexpected Homer likened the generation of man to the fall of observations with wide relevance to genetics as a leaves. Addison introduced a continuous stochastic Bo-ok reviews 239 o n A p ril 5 , 2 0 2 1 b y g u e st. P ro te cte d b y co p yrig h t. h ttp ://jm g .b m j.co m / J M e d G e n e t: first p u b lish e d a s 1 0 .1 1 3 6 /jm g .1 6 .3 .2 3 8 -a o n 1 Ju n e 1 9 7 9 . D o w n lo a d e d fro m http://jmg.bmj.com/