Identification of Duchenne muscular dystrophy carrier by detecting junction fragments between the breakpoints of introns / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the value of the junction fragments between the breakpoints of introns in identifying deletional Duchenne muscular dystrophy (DMD) carriers.</p><p><b>METHODS</b>A DMD family (including the index patient III2 and the suspected carrier II3) and a sporadic DMD case (including the patient II1 and his mother I2) were studied. The patient III2 of the DMD family was identified as having exons 31-43 deletion of the DMD gene, and the sporadic patient II1 had exons 45-54 deletion. A PCR-based genome-walking method was used to locate the breakpoints in the corresponding introns. The junction fragments of the patients and their female relatives waiting for a diagnosis were amplified by PCR with primers adjacent to the deletion junctions.</p><p><b>RESULTS</b>PCR amplification yielded identical positive results for the female suspected carrier II3 of and the index patient of the DMD family, and the former was thus diagnosed as a carrier of DMD. PCR amplification of the sporadic patient's mother I2 showed a negative result, but the patient II1 had a positive result, so that the patient's mother was excluded as being a carrier of DMD.</p><p><b>CONCLUSION</b>Routine PCR technique for detecting the junction fragments allows identification of carriers among female relatives of patients with deletional DMD.</p>