New distal marker closely linked to the fragile X locus

Abstract

We have isolated II-10, a new X-chromosomal probe that identifies a highly informative two-allele TaqI restriction fragment length polymorphism at locus DXS466. Using somatic cell hybrids containing distinct portions of the long arm of the X chromosome, we could localize DXS466 between DXS296 and DXS304, both of which are closely linked distal markers for fragile X. This regional localization was supported by the analysis, in fragile X families, of recombination events between these three loci, the fragile X locus and locus DXS52, the latter being located at a more distal position. DXS466 is closely linked to the fragile X locus with a peak lod score of 7.79 at a recombination fraction of 0.02. Heterozygosity of DXS466 is approximately 50%. Its close proximity and relatively high informativity make DXS466 a valuable new diagnostic DNA marker for fragile X.

IDS gene-pseudogene exchange responsible for an intragenic deletion in a hunter patient

“…Pseudogene exons I1 and 111 hybridize both with the 7.5-kb EcoRI fragment and with the 2.7-kb and the 6.4-kb Hind111 fragments, respectively. 10, locus DXS 465 (Hulsebos et al, 1991); probe U6.2, locus DXS 304 (Dahl et al, 1989); probe VK21A, locus DXS 496 (Suthers et al, 1989); and specific exon probes obtained from pB2Sc17 by PCR with the following sets of primers: exon 11: EII.5' and EII.3' (135 bp); exon 111: EIII.5' and EIII.3' (115 bp). Microsatellite at locus DXS1113 was analyzed as described by Weber et al (1993).…”

Mutations of the iduronate-2-sulfatase (IDS) gene in patients with hunter syndrome (mucopolysaccharidosis II)

“…All patients have been characterized by Southern blotting (Wehnert et al, 1992, Schroder et al, 1993, using a partial cDNA clone of the IDS gene (pc2S15, Wilson et al, 1990) and three flanking polymorphic markers (VK21A, VK23B and 11-10 as probes (Yu et al, 1990;Suthers et al, 1991;Hulseboes, 1991).…”

Hunter syndrome: Gene deletions and rearrangements

“…Hunter patients using a partial IDS cDNA clone (pc2S15) and three flanking polymorphic markers (VK21A, 11.10, and U6.2) (Dahl et al, 1989;Suthers et al, 1989;Hulsebos et al, 1991) which established order is cen-VK21A-IDS-II.1O-U6.2tel (Davies and Craig, 1991). Patients were also tested for the 1327 C-T mutation described by Sukegawa et al (1992).…”