Identification of disease-causing point mutations in DMD patients' dystrophin gene without large deletions/duplications / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To detect the disease-causing point mutations in the dystrophin gene of Duchenne muscular dystrophy (DMD) patients.</p><p><b>METHODS</b>The approach of denaturing high performance liquid chromatography (DHPLC) coupling with sequencing was used to screen the point mutations of 79 exons and the untranslated regions of dystrophin gene without large deletions/duplications, which was in 6 unrelated DMD probands from 6 DMD families.</p><p><b>RESULTS</b>Five disease-causing mutations, 697-698insGT, C616T, G1255T, C4279T, and C2302T, were ides created the new stop codons in downstream sites of mutations, respectively. In addition to the disease-causing point mutations, a point mutation T5586+61A in intron 39 was also found at patient 3, and a missense mutation A694T in exon 8 was detected at patient 5. Four point mutations, C2168+13T, 5740-13dupG, G5234A and C5280T, were also detected at patient 6 whose causative point mutation was unavailable. Seven point mutations have not been reported previously. Bi-directional PCR amplification of specific alleles (Bi-PASA) method was established to distinguish the haplotypes of heterozygote or homozygote in a single PCR reaction.</p><p><b>CONCLUSION</b>Via automated DHPLC screening or detecting the subexonic mutations in dystrophin gene is feasible to clinical laboratories, and also is a superior method in terms of sensitivity and efficiency.</p>