Locus-specific or gene-specific probes can be used to identify known aberrations that cause fetal or congenital abnormalities; for example, 22q11 deletions in DiGeorge syndrome, 7q11.23 deletions in Williams syndrome, and dystrophin mutations in Duchenne muscular dystrophy [19,20,21]. This evidence concerns the gene DMD and Duchenne muscular dystrophy.