NEUTRAL POLYMORPHISMS IN THE DELETION PRONE REGIONS OF THE DYSTROPHINGENE

The single-strand conformational polymorphism technique was used to se arch for neutral polymorphisms in 18 PCR-amplified dystrophin gene fra gments. Out of the seven polymorphisms (six intronic and one exonic) d etected in Caucasians, one was absent from the Oriental population. Si gnificant differences in allele frequencies between the two population s were observed for three of the intronic polymorphisms, In Caucasians , one variant position occurred per 728 bp of the total DNA or one per 483 bp of the intronic sequence; the corresponding average heterozygo sities were 0.04 and 0.06%, respectively.