Molecular Mechanisms of Xeroderma Pigmentosum

To understand the molecular mechanisms of XP, XP mouse models have been used, and mice deficient in XPA, XPC, XPD, XPG, XPF, and XPA/CSB have been produced and analysed. A recent elegant technique of targeting gene replacement in mouse embryonic stem cells has provided researchers with the ability to generate mutant mice defective in any specific gene(s). 32 Animals generated in this way display phenotypes and symptoms of XP patients, and have provided valuable tools to understand how and where the deficiency in DNA repair may lead to tumor formation, and also in studies of developmental biology and the aging process. Mouse studies have recently contributed to our understanding of the role of ink4a-Arf in increasing the risk of melanoma photocarcinogenesis in an XPC mutant background. As with many other genetic defects, the distribution of XP globally is not uniform. In most cases the frequency of mutation of a particular trait depends when and where a specific mutation arose, and the longer ago that is, the greater the frequency of mutant in the population unless some selective pressure prevailed. Another factor responsible for the high incidence of any mutation is consanguinity. One of the last chapters analyzes the world distribution of XP and shows that Japan has the highest incidence of XP and of varying complementation groups. After Japan perhaps Egypt suffers most from this inborn error. Here it is also shown that the most common complementation groups are XPA and XPC followed by XPV. XPB and XPE are least frequent. In a recent publication, however, 16 Japanese patients with XPV have been diagnosed and confirmed both clinically and at the cellular level. There is no evidence that interest in XP is waning, and this book should provide both the expert and novice researcher in the field with an excellent overview of the current status of research and pointers to future research goals.

Sham im I. Ahma d is a Senior Lecturer at Nottingham Trent University, Nottingham, England. After obtaining his MSc from Patna University, India, and his PhD from Leicester University, England, he joined Nottingham Polytechnic which subsequently became Nottingham Trent University. For about three decades he has been working in the field of DNA damage and repair particularly on Near UV photolysis of biological compounds, production of free radicals and their implications on human health including skin cancer and xeroderma pigmentosum. Also compounds inducing double strand DNA damage, 8-methoxypsoralen +UVA, mitomycin C, and nitrogen mustard have been under investigation including their importance in psoriasis treatment and Fanconi anemia. Additional research included: thymineless death in bacteria, genetic control of nucleotides catabolism, development of anti-AIDS drug, control of microbial infections of burns, phages of thermophiles and microbial flora of Chernobyl after the accident. In 2003 he received a prestigious “Asian Jewel Award” in Britain for “Excellence in Education”. He is also the Editor of the book, Molecular Mechanisms of Fanconi Anemia, published by Landes Bioscience.Fumio Hanaoka is a Professor at the Graduate School of Frontier Biosciences, Osaka University and the Program Leader of the Solution Oriented Research for Science and Technology of the Japan Science and Technology Agency, Japan. He received his undergraduate and PhD degrees from the University of Tokyo and did his Postdoctoral at McArdle Laboratory for Cancer Research, University of Wisconsin, Madison, USA. He joined the University of Tokyo in 1980 and in 1989 moved to RIKEN Institute as the Head of the Radiation Research Laboratory. In 1995, he joined the Institute for Molecular and Cellular Biology (now known as Graduate School of Frontier Biosciences), Osaka University. His main research interests include the molecular mechanisms of DNA replication and repair in eukaryotes. He served as the President of Molecular Biology Society of Japan (2005-2007) and has been serving on several editorial boards, including Journal of Biological Chemistry and Genes to Cells.