[Relationship of phenotype with type of deletion of dystrophin gene]

To detect the distribution characteristics of dystrophin gene deletions in the northeastern of China and the relationship of severity with type of deletion.

To screen deletion distribution of 124 DMD/BMD patients via multiplex PCR, male high-risk fetuses were detected deletion by the same method.

The deletion frequency was 49%. Deletions located in the regions of exons 45 - 53 and exons 8 - 19 were 41 (67%) and 13 (21%) cases respectively, and in 5 (8%) cases deletions were scattered over both regions, still 2 cases (3%) were checked up deletions lying in exons 34 and 43; there were 9 cases of in-frame deletions and 49 frameshift mutations in all deletions; of 30 high-risk fetuses 10 male ones were screened deletions, who had the same deletion-segments as their probands.

The distribution of dystrophin gene deletions in the northeastern of China cluster mainly in two hot-spots, neighboring regions of exon 8 might be a real deletion "hot spot" in this region; the phenotype is associated with the type of gene deletion, the phenotype is BMD when in-frame deletions occur; severe DMD when frameshift mutations occur. Multiplex PCR method provides the short-cuts for detecting patients and making prenatal gene diagnosis.