Statistics from Altmetric.com
Edited by Joyce Whittington and Tony Holland. Cambridge University Press, 2004, pp 213, £60.00 (hardback). ISBN 0-521-84029-5
In their preface to this roughly 200 page book, which chronicles the Cambridge Prader-Willi syndrome (PWS) study, the authors Tony Holland (Chair in Learning Disabilities) and Joyce Whittington (Senior Research Assistant) describe their study as “a process of discovery that included getting to know many people with Prader-Willi syndrome and their families”. Following a thorough and painstaking process of identification and ascertainment, the authors managed to identify 96 patients within the Anglia and Oxford Health regions in whom the diagnosis of PWS was secure, enabling the birth prevalence (1 in 20 000) and population prevalence (1 in 50 000) to be calculated. The authors then carried out home visits with completion of a detailed semi-structured questionnaire in 61 of these patients. A further 42 PWS patients from outside the study area were studied as were 32 subjects with learning disability who did not have PWS. The information gathered was used to determine predictive features for diagnosis, the behavioural and cognitive phenotypes, and the incidence and nature of psychiatric disorders.
The combination of rigorous diagnostic ascertainment, detailed first hand information, and thorough analysis make this a landmark study. The book is well written, the authors beginning with a succinct description of various aspects of PWS, including the genetic neuroendocrine, satiety, sleep, temperature, and neuroimaging abnormalities. The genetic and neuropathology sections are particularly commended for being intelligible to readers with little knowledge in these fields.
Only a brief mention of some of the study findings can be given here. Ninety nine per cent of patients with PWS can be diagnosed correctly if all four of the following features are present: floppy at birth; weak cry/inactivity in infancy; poor suck at birth; and childhood obesity. Psychometric testing confirmed a roughly 40 point downward shift in global IQ. Patients with disomy (inheritance of two maternal chromosomes 15 and hence loss of the paternal contribution in the critical 15q11–13 region) showed higher verbal abilities than patients with PWS caused by a deletion on the paternal chromosome 15. Disappointingly, perhaps, the celebrated ability of PWS individuals to complete complicated jigsaw puzzles did not related to enhanced ability and probably reflects plenty of practice related to the repetitive behaviour patterns of the condition! A striking feature was the prevalence of psychotic illness in older patients. After the age of 28 years, 7 of 15 patients had experienced a major psychotic episode. This included all of the five patients with disomy. This latter finding, which has considerable therapeutic implications, calls for further collaborative study.
This book is compulsory reading for anyone with a serious interest in PWS—I have ordered a copy for each member of the Yorkhill multidisciplinary Prader-Willi Clinic! Those seeking more information on this fascinating and elusive disorder will find plenty of factual information to dip into. Anyone attempting to write a paper about PWS will be greatly helped by the numerous references given and the intelligent discussion that accompanies them.