OBJECTIVETo establish an efficient method which can be easily used for detecting CTG trinucleotide repeats in myotonic dystrophy type 1 (DM1).

METHODSTri-primer polymerase chain reaction (TP-PCR) combined with electropherogram was used to detect CTG repeats in the 3'-untranslated region of DMPK gene. Twenty non-related DM1 patients and 24 healthy controls were selected.

RESULTSAll patients were found to have carried pathologic alleles containing more than 100 CTG repeats, while the healthy controls have carried 5-37 CTG repeats.

CONCLUSIONTP-PCR combined with electropherograms may provide a highly sensitive, specific and accurate method which is less time-consuming and easier to perform for the detection of pathologic alleles in DM1 patients.