Isolation of a random cosmid clone, cX5, which defines a new polymorphic locus DXS148 near the locus for Duchenne muscular dystrophy

Abstract

We have isolated a random cosmid cX5 (DXS148), which maps into a small Xp21 deletion associated with Duchenne muscular dystrophy (DMD), chronic granulomatous disease (CGD), retinitis pigmentosa (RP) and McLeod syndrome, cX5 maps proximally outside several other deletions associated with DMD, glycerol kinase deficiency (GK) and adrenal hypoplasia (AHC). The following order of loci is proposed: centromere-OTC-cX5 (DXS148)-754 (DXS84)-PERT87 (DXS164)/DMD-telomere. A subclone cX5.7, isolated from this cosmid, identifies an MspI RFLP, with a minor allele frequency of 35%. This probe forms an important adjunct to the existing RFLPs for family studies in Duchenne muscular dystrophy.

Single-strand conformational polymorphisms (SSCP): detection of useful polymorphisms at the dystrophin locus

“…Because SSCP analysis does not necessarily detect all D N A variants (Orita et al 1990b), these figures therefore represent a minimum estimate. The intronic variation in the dystrophin gene observed here (heterozygosity of 0.08% per nucleotide position) is in the same range as other estimates, 0.09% for the X chromosome using restriction site polymorphisms (Hofker et al 1986), 0.07% for the retinoblastoma gene region (Yandel et al 1989) and 0.03%-0.06% for other autosomal loci using SSCP (Orita et al 1990b). These values are low as compared, for example, to the divergence of 0.38% between two independently determined sequences from pseudo-eta-globin gene locus (Bailey et al 1991).…”

Isolation and characterization of cell hybrids containing human Xp-chromosome fragments

“…and pERT469 ; pERT87-l and pERT87-30 ( Monaco et al. 1985): pX j-l.l (Rayet al, 1985); 754 (Hofkeret al, 1985), cX5.7 and cX5.4 (Hofker et al. 1986); OTC cDNA (Horwich et al.…”

Direct analysis of single‐nucleotide polymorphism on double‐stranded DNA by pyrosequencing

“…Single‐nucleotide polymorphism (SNP) can be characterized as a substitution, insertion or deletion at a single base position on a DNA strand. There is expected to be on average one SNP for every 1000 bases of the human chromosomes [1–3], and some variations located in genes are suspected to alter both protein structure and expression level. The number of detected SNPs at the DNA level has expanded dramatically in the last decade due to the increase in sequencing data from different species.…”