Molecular Bases of Nucleotide Expansions -- Mechanisms of DNA Repeat Expansion -- Disorders Associated with Non-coding Repeats -- Molecular Correlates of Fragile X Syndrome and FXTAS -- The Neglected Fragile X Mutations: FRAXE and FRAXF -- Friedreich Ataxia -- Dodecamer Repeat Expansion in Progressive Myoclonus Epilepsy 1 -- Myotonic Dystrophies Types 1 and 2 -- Spinocerebellar Ataxia Type 8 -- Recent Progress in Spinocerebellar Ataxia Type 10 -- Disorders Associated with Coding Repeats -- Polyglutamine Diseases -- The Enigma of Spinocerebellar Ataxia Type 6 -- Disorders Associated with Repeats in an Undetermined Location -- Spinocerebellar Ataxia Type 12 and Huntington's Disease-Like 2: Clues to Pathogenesis -- Postscript -- Current Issues and Therapeutic Prospects. Human neurological and neuromuscular disorders caused by nucleotide expansion, first discovered in 1991, are the focus of growing interest of practicing physicians and of interested biomedical researchers. This volume represents a comprehensive and up-to-date description of many of the better-studied disorders. The expert authors discuss molecular, clinical and pathological aspects of the diseases as well as our current understanding of their underlying mechanisms. Of special interest are ideas and initial results of the different therapeutic strategies that can be employed to overcome some of the disorders. As a summary of the state-of-the-art research in this field, this book is of value to human geneticists, molecular biologists and biochemists as well as to practicing neurologists and pediatricians.