Detection of triplet repeat expansion in the human genome by use of hybridization signal intensity.
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.
Sawada
K
K
Taisho Laboratory of Functional Genomics, Nara Institute of Science and Technology, Nagoya, Japan. ksawada@tsuru.med.nagoya-u.ac.jp
Doyu
M
M
Tanaka
F
F
Sobue
G
G
Kato
K
K
D000483:Alleles; D015139:Blotting, Southern; D016022:Case-Control Studies; D004252:DNA Mutational Analysis / Q000379:methods*; D005821:Genetic Techniques; D006801:Humans; D017827:Machado-Joseph Disease / Q000175:diagnosis / Q000235:genetics; D020191:Myoclonic Epilepsies, Progressive / Q000175:diagnosis / Q000235:genetics; D009693:Nucleic Acid Hybridization / Q000379:methods*; D020754:Spinocerebellar Ataxias / Q000175:diagnosis / Q000235:genetics; D019680:Trinucleotide Repeat Expansion