The clinical picture of diseases, caused by trinucleotide repeats, such as fragile X syndrome, myotonic dystrophy, Huntington's disease and forms of spinocerebella ataxia, provide the starting point for this authoritative review volume. The book proceeds to integrate the current understanding of the molecular pathologies of these diseases, their genotype-phenotype relationships, the mutational processes involved and the laboratory and clinical issues relating to genetic testing for these disorders. Clinicians and researchers in genetics, neuroscience, pediatrics and psychiatry will all benefit from the comprehensive overviews contributed by recognized world experts.