Screening of gene deletions by polymerase chain reaction in Japanese patients with Duchenne muscular dystrophy.

Gene deletions were screened in 49 Japanese Duchenne muscular dystrophy patients from 43 families, using the polymerase chain reaction. Enzymatic amplification was carried out on six regions prone to deletion. Fifteen of 43 families (33%) had gene deletions in at least one of the six regions. This frequency was almost the same as that previously reported in Caucasians. The mid-part of the dystrophin gene was the location most frequently deleted. The frequency of deletion of the region encompassing exon 45 was higher in Japanese families (18.4%) than in Caucasians.