Novel triplet repeat containing genes in human brain: Cloning, expression, and length polymorphisms
- Johns Hopkins Univ. Baltimore, MD (United States)
Human genes containing triplet repeats may markedly expand in length and cause neuropsychiatric disease, explaining the phenomenon of anticipation (increasing severity or earlier age of onset in successive generations in a pedigree). To identify novel genes with triplet repeats, the authors screened a human brain cDNA library with oligonucleotide probes containing CTG or CCG triplet repeats. Fourteen of 40 clones encoded novel human genes, and 8 of these inserts have been sequenced on both strands. All contain repeats, and 5 of the 8 have 9 or more consecutive perfect repeats. All are expressed in brain. Chromosomal assignments reveal a distribution of these genes on multiple autosomes and the X-chromosome. Further, the repeat length in two of the genes is highly polymorphic, making them valuable index linkage markers. The authors predict that many triplet repeat-containing genes exist; screening with the CTG probe suggests approximately 50-100 genes containing this type of repeat are expressed in the human brain. Since additional disorders, such as Huntington's disease, bipolar affective disorder, and possibly others, show features of anticipation, they suggest that these novel human genes with triplet repeats are candidates for causing neuropsychiatric diseases.
- OSTI ID:
- 6975540
- Journal Information:
- Genomics; (United States), Vol. 16:3; ISSN 0888-7543
- Country of Publication:
- United States
- Language:
- English
Similar Records
Isolation and characterization of human cerebellum cDNAs containing polymorphic CAG trinucleotide repeats
Demonstration by sequence analysis of a linkage disequilibrium between polymorphic CCG repeat and the CAG expansion in HD gene