Determination of carrier status in Duchenne and Becker muscular dystrophies by quantitative polymerase chain reaction and allele-specific oligonucleotides

Detection of carriers of Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD), in the deletion cases, involves calculating gene dosage from Southern blots. We show that the analysis of dosage can also be made from the polymerase chain reaction (PCR) with use of allele-specific oligonucleotides (ASOs). The deletion-prone exons are amplified, transferred to a membrane, and hybridized with ASOs complementary to the exons; the autoradiographic bands are then quantified with a densitometer. After determining the quantitative conditions of the amplification reaction, we were able to identify deletions in a DMD/BMD carrier female. The determination of carrier status via PCR removes several of the technical limitations of Southern analysis and is also cost- and labor-effective.