Non-isotopic analysis ofsingle strand conformation polymorphism (SSCP)intheexon 13region ofthehumandystrophin gene

Morethan30%ofDuchenneandBecker muscular dystrophy (DMD/BMD)patients havenogrossDNA rearrangements like deletions orduplications. Thelargesize ofthecoding sequence ofthedystrophin gene(11kilobases) complicates systematic identification ofpointmutations. Recently reported approaches basedon genomic DNA or mRNA show thatchemical cleavage ofmismatchesisan effective but timeconsumingand technically demanding methodfortheidentification of pointmutations inthehumandystrophin gene.We haveusedafastandconvenient systemconsisting ofPCR amplification of genomicDNA,non-isotopic SSCPanalysis, anddirect sequencing ofPCR productsforthedetection ofmutations in exon13andadjacent intronsequences. Sixty-eight DMD patients withoutdetectable deletions orduplications were analysed, resulting intheidentification ofa pointmutationinthecodingsequenceandtwopolymorphisms inthe5' flanking intron. TheC toT changeofthe first nucleotide inthethirdtriplet leads toastopcodonandseemstobethecause ofthefunctional deficiency ofthegene product inthispatient. (J7 MedGenet1993;30:951-4)