The De Lange Syndrome.

This is a book which clinical geneticists and those interested in malformations will enjoy looking at and reading. It is probably best bought together with the companion volumes rather than in isolation. It supplements but does not replace other illustrated catalogues which have been recently published on the malformation syndromes. Alzheimer's disease is a moderately infrequent form of presenile dementia, with a well-defined course and clinical picture, and characteristic cerebral pathology. Genetically it is interesting because of the indications of genetic heterogeneity within this clinico-pathologically delimited syndrome. A number of families have been described, in his contribution to the symposium Pratt says 'more than a dozen', in which a completely typical form of autosomal dominant inheritance is shown, with equal sex representation, and nearly complete pene-trance. In comprehensive series, however, selected on a clinico-pathological basis, these typical families do not appear; and what one sees instead is a moderately raised familial incidence and a female preponderance of about 3:1, ie, the indications of a polygenic genetical basis. The genetical evidence, therefore, is strongly in favour of regarding the syndrome as being a mixture of at least two different and independent conditions. This is a conclusion which, for the most part, both clinicians and pathologists are unwilling to accept, as is made plain in these papers. The symposium reported here was predominantly a pathological one, with interesting and original pathological work. Participants came from Belgium, Ger-many, the Argentine, Sweden, Hungary, the USA (7) and Britain (10). Active work is going on in histology, histochemistry, and electron-microscopy. Most promising , perhaps, is the study of the ultramicroscopic structure, ie the abnormal intracellular microtubules, which differentiate more than one kind of lesion, and may lead to a successful breaking down of the clinico-pathological continuum extending into normal sene-scence, senile dementia, and cerebrovascular disease, by which most workers are at present both obsessed and bewildered. The reviewer would suppose that this book is an important one for the neuropathologist. Its genetical interest is not great. Apart from Pratt's paper reviewing the present state of genetical understanding, the main interest lies in the communication by Jacob (Marburg, Germany) of a family with 6 females in 3 generations showing a form of Alzheimer's disease with, in every case, the unusual feature of myoclonic twitchings appearing early in the course. The literature is reviewed by Jacob. The book is well produced, with an abundance of good pathological …