title: Isolation of probes detecting restriction fragment length polymorphisms from X chromosome-specific libraries: potential use for diagnosis of Duchenne muscular dystrophy.
abstract: We have isolated 23 human X chromosome-specific DNA fragments from lambda libraries, prepared from flow-sorted X chromosomes. To increase diagnostic potential for X-linked genetic disorders, including Duchenne muscular dystrophy (DMD), the fragments were tested for restriction fragment length polymorphisms (RFLPs) with six restriction enzymes. All fragments were regionally mapped to segments of the X chromosome with a panel of somatic cell hybrids and with human cell lines carrying unbalanced chromosomal abnormalities. Two of the isolated probes detected a high frequency RFLP. One, 754, maps between Xp11.3 and Xp21 and detects a PstI polymorphism with an allele frequency of 0.38. The other, 782, maps between Xp22.2 and Xp22.3 and reveals an EcoRI polymorphism with an allele frequency of 0.40. According to a pilot linkage study of families at risk for Duchenne muscular dystrophy, 754 gives a maximum Lod score of 7.6 at a recombination fraction of 0.03. Probe 782 lies telomeric to DMD with a maximum Lod score of 2.2 at a recombination fraction of 0.17. Using our X-chromosomal probes and a set of autosomal probes, isolated and examined in an identical way, we found a significantly lower RFLP frequency for the X chromosome as compared to the autosomes.
authors.forename: M H
authors.initials: MH
authors.lastname: Hofker
authors.forename: M C
authors.initials: MC
authors.lastname: Wapenaar
authors.forename: N
authors.initials: N
authors.lastname: Goor
authors.forename: E
authors.initials: E
authors.lastname: Bakker
authors.forename: G J
authors.initials: GJ
authors.lastname: van Ommen
authors.forename: P L
authors.initials: PL
authors.lastname: Pearson
mesh_terms: D000818:Animals; D002460:Cell Line; D002874:Chromosome Mapping; D006224:Cricetinae; D004262:DNA Restriction Enzymes; D005260:Female; D006580:Genetic Carrier Screening; D008040:Genetic Linkage; D005819:Genetic Markers; D006801:Humans; D006822:Hybrid Cells; D008297:Male; D009136:Muscular Dystrophies / Q000175:diagnosis / Q000235:genetics*; D010375:Pedigree; D011110:Polymorphism, Genetic; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014960:X Chromosome
chemical_list: D005819:Genetic Markers; D004262:DNA Restriction Enzymes