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 Bec ker muscular dystrophies were analysed blind by restriction fragment l ength polymorphisms (RFLPs) and a new, non-radioactive direct test bas ed on competitive polymerase-chain-reaction (PCR) amplification. All o bligate carriers were correctly diagnosed by RFLPs and competitive PCR , and 7 women with a 99% risk of being carriers were also diagnosed ca rriers by competitive PCR. There were no false positives or false nega tives. Only 1 PCR result was non-informative. Our test allows rapid, p recise, and direct carrier diagnosis of women whose relatives have a k nown deletion of the dystrophin gene.