Detection of Triplet Repeat Expansion in the Human Genome by Use of Hybridization Signal Intensity

✍ Scribed by Ko-ichi Sawada; Manabu Doyu; Fumiaki Tanaka; Gen Sobue; Kikuya Kato

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 274 KB
• Volume: 286
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.2000.4786

✦ Synopsis

Triplet repeat disease is a group of hereditary neurodegenerative disorders caused by expansion of trinucleotide repeats such as CAG/CTG, CGG/CCG, and GAA/TTC. Direct detection of the expansion in the patient's genome shortcuts the tedious process needed for identification of disease genes by conventional approaches. Here we describe a method to detect triplet repeat expansion from the hybridization signal intensity. Using a digoxigenin-labeled (CTG)9 probe, the hybridization intensity and number of repeats showed a good linear correlation. The technique detected expansion in genomic DNA in all cases with moderate or large expansion. Even in the case of a small expansion, this method could detect the mutant fragment. The technique has advantages over related techniques because it is more sensitive and can be applied to cases where a small repeat expansion is involved.