This Article  • Full text  • PDF  • Reply to article  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citation map  • Citing articles on HighWire  • Citing articles on ISI (48)  • Contact me when this article is cited  Related Content  • Similar articles in this journal  Social Bookmarking   What's this?

Russell L. Margolis, MD; Melvin G. McInnis, MD; Adam Rosenblatt, MD; Christopher A. Ross, MD, PhD

Arch Gen Psychiatry. 1999;56:1019-1031.

Trinucleotide, or triplet, repeats consist of 3 nucleotides consecutively repeated (eg, CCG CCG CCG CCG CCG) within a region of DNA, a not uncommon motif in the genome of humans and other species. In 1991, a new type of genetic mutation was discovered, known as a dynamic or expansion mutation, in which the number of triplets in a repeat increases and the length becomes unstable. During the past decade, nearly 20 diseases—including Huntington disease, 2 forms of the fragile X syndrome, and myotonic dystrophy—caused by trinucleotide repeat expansions have been identified. The unstable nature of the expanded repeat leads to remarkable patterns of inheritance in these diseases, distinctly at odds with traditional notions of mendelian genetics. We review the clinical and genetic features of these disorders, with a particular emphasis on their psychiatric manifestations. We also critically examine the hypothesis that expansion mutations may have an etiologic role in psychiatric diseases such as bipolar disorder, schizophrenia, and autism.

From the Department of Psychiatry and Behavioral Sciences, Divisions of Neurobiology (Drs Margolis, Rosenblatt, and Ross) and Psychiatric Genetics (Dr McInnis), Department of Neuroscience (Dr Ross), and Program in Molecular and Cellular Medicine (Dr Ross), Johns Hopkins University School of Medicine, Baltimore, Md.

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati     What's this?

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Phenotypic and genetic complexity of psychosis: Invited commentary on ... Schizophrenia: a common disease caused by multiple rare alleles
Craddock et al.
Br. J. Psychiatry 2007;190:200-203.
ABSTRACT | FULL TEXT  

The Cerebellum in Schizophrenia: A Case of Intermittent Ataxia and Psychosis--Clinical, Cognitive, and Neuroanatomical Correlates
Turner and Schiavetto
J. Neuropsychiatry Clin. Neurosi. 2004;16:400-408.
ABSTRACT | FULL TEXT  

Diagnosis of Huntington Disease
Margolis and Ross
Clin. Chem. 2003;49:1726-1732.
ABSTRACT | FULL TEXT