Carrier detection of Duchenne/Becker muscular dystrophy: computer-assisted direct quantitation of gene amplification products.

An improved method by quantitative dystrophin gene deletion analysis was developed for the detection of Duchenne/Becker muscular dystrophy (DMD/BMD) carriers. Exon 52, which had been found to be deleted in DMD probands, was amplified for female family members, together with exon 60 as a reference, at the exponential phase of polymerase chain reaction. The products were separated by electrophoresis, the band intensities on gel photographs were quantitated, and the target/control ratios were calculated. The values for three heterozygous mothers were approximately half those for normal individuals and two definite non-heterozygous mothers. This procedure is easy, rapid and useful for the carrier diagnosis of DMD/BMD.