Millions of children and adults around the world are affected by developmental disabilities. This has affected the cognitive, motor, and emotional aspects of their lives. Although there has been enormous progress in our understanding of the pathophysiological aspects of neurodevelopmental disorders, many aspects of these disorders remain unknown. For instance, there are 6 million people affected by Down syndrome around the world. While advances in clinical care and surgical techniques have led to a drastic increase in life expectancy of people with Down syndrome, no effective treatments are available to restore cognitive function in affected people. For this reason, there is an urgent need to better understand the mechanisms behind cognitive disability and develop new therapies for Down syndrome and similar neurodevelopmental disorders.
The purpose of the current book is to provide examples of methods for understanding the molecular mechanisms, clinical aspects, diagnosis, and management of behavioral abnormalities in people with intellectual disability.
The first chapter by Fang Xu and Peining Li discusses the role of cytogenomic abnormalities in people with intellectual disability. Following extensive review of the methodology used to perform cytogenetic and genomic analyses, they discuss in vitro cellular phenotyping and in vivo animal modeling of neurodevelopmental abnormalities.
In the second chapter, Adrienne Elbert and Nathalie Berube discuss the role of chromatin structure in people with intellectual disability. The chapter starts with the basic concept of chromatin organization and provides a few examples in which altered chromatin structure plays a significant role in the occurrence of the phenotype.
Chapters 3 and 4 provide examples of rare forms of cognitive disability in adults. These abnormalities are a combination of a variety of motor and cognitive dysfunctions. In Chapter 3, Danilo Moretti-Ferreira describes Magenis syndrome, a rare form of intellectual disability with extensive overlap with other forms of intellectual disability, particularly Down syndrome. This is followed by a chapter by Karaca, Tan, and Tan describing a rare form of intellectual disability with very characteristic motor problems.
The last chapter (Chapter 5) is dedicated to studying the effects of sexual maturation in people with severe and moderate intellectual disability. In this extensive chapter, Stanislava Mandzáková walks us through behavioral aspects of sexual maturation in people with developmental abnormalities and tests the effects of different factors on sexual behaviors in affected people and their caregivers.
Advances in automated full sequencing systems now enable genotyping in a large number of individuals. Sophisticated imaging systems now provide the ability to accurately study minor alterations in brain circuits, and increased availability of high-throughput assay systems allows testing the therapeutic and toxic effects of an incredibly large number of chemicals in vitro, further accelerating the process of understanding the pathogenesis of neuronal abnormalities and developing new therapeutic strategies for neurodevelopmental disorders.
I would like to dedicate this book to the families of individuals with intellectual disability. While they experience incredible pain and suffering, many do not wait for others to act. During my many years of work on neurodevelopmental disorders, I have come to the conclusion that without the contribution and active participation of parents, brothers and sisters, and other members of the immediate family of individuals with intellectual disability, it would not have been possible to get to where we are now. While developmental disabilities are not considered a top priority for funding and research by governments in many regions of the world, the last decade has witnessed multiple examples in which a few hard-working and persistent family members of individuals with intellectual disability made an enormous contribution through direct involvement and by persuading others to become involved. This has indeed made a difference in fundamental research, clinical care, and the development of treatments for many aspects of neurodevelopmental disorders. Dedicating this book to these family members is to thank them for believing that, once scientists are equipped with knowledge of the molecular mechanisms of brain function and the proper tools to modify the brain circuits involved in cognition, they can make a huge difference in all aspects of the lives of people with intellectual disability.
Dr. Ahmad Salehi Clinical Associate Professor Department of Psychiatry & Behavioral Sciences Stanford Medical School USA Contents
Cytogenomic Abnormalities and Dosage-Sensitive Mechanisms for Intellectual and Developmental Disabilities Fang Xu and Peining Li
Chromatin Structure and Intellectual Disability Syndromes Adrienne Elbert and Nathalie G. Bérubé
Chapter 3 Intellectual and Behavioral Disabilities in Smith — Magenis Syndrome Danilo Moretti-Ferreira
Humans Walking on All Four Extremities With Mental Retardation and Dysarthric or no Speech: A Dynamical Systems Sibel Karaca, Meliha Tan and Üner Tan
Sexuality and Sex Education in Individuals with Intellectual Disability in Social Care Homes Stanislava Listiak Mandzakova
Developmental Disabilities - Molecules Involved, Diagnosis, and Clinical Care Edited by Ahmad Salehi Contributors: Peining Li, Fang Xu, Danilo Moretti-Ferreira, Stanislava Mandzáková, Nathalie G. Berube, Adrienne Elbert, Uner Tan, Sibel Karaca, Meliha Tan Publishing Process Manager: Iva Simcic First published July, 2013 A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechopen.com ISBN 978-953-51-1177-1