RAPID DIRECT DIAGNOSIS OF DELETIONS CARRIERS OF DUCHENNE AND BECKER MUSCULAR-DYSTROPHIES

13 families and 34 women at risk of being carriers of Duchenne and Becker muscular dystrophies were analysed blind by restriction fragment length polymorphisms (RFLPs) and a new, non-radioactive direct test based on competitive polymerase-chain-reaction (PCR) amplification. All obligate carriers were correctly diagnosed by RFLPs and competitive PCR, and 7 women with a 99% risk of being carriers were also diagnosed carriers by competitive PCR. There were no false positives or false negatives. Only 1 PCR result was non-informative. Our test allows rapid, precise, and direct carrier diagnosis of women whose relatives have a known deletion of the dystrophin gene.