Genetic linkage study demonstrates the DMD locus lies between flanking markers on the X chromosome, indicating a genetic distance of 40 centimorgans.
Key Points
To establish a genetic linkage map of the short arm of the human X chromosome and define the location of the Duchenne muscular dystrophy (DMD) gene relative to cloned DNA markers.
Analyzed the inheritance and segregation patterns of two restriction fragment length polymorphisms (RFLPs) located at Xp21–Xp223 and Xp110–Xp113 relative to the DMD locus.
Estimated genetic recombination distances across the Xp110 to Xp223 region on the short arm of the human X chromosome.
Determined the genetic distance between Xp110 and Xp223 to be approximately 40 centimorgans (cM).
Confirmed that the DMD mutation is flanked between Xp223 and Xp110, providing experimental evidence that 1 cM corresponds to approximately 1,000 kilobase pairs in this chromosomal region.