Showing papers by "Marcy E. MacDonald published in 1992"

The Huntington's disease candidate region exhibits many different haplotypes.

Abstract: Analysis of 78 Huntington's disease (HD) chromosomes with multi-allele markers revealed 26 different haplotypes, suggesting a variety of independent HD mutations. The most frequent haplotype, accounting for about one third of disease chromosomes, suggests that the disease gene is between D4S182 and D4S180. However, the paucity of an expected class of chromosomes that can be related to this major haplotype by assuming single crossovers may reflect the operation of other mechanisms in creating haplotype diversity. Some of these mechanisms sustain alternative scenarios that do not require a multiple mutational origin for HD and/or its positioning between D4S182 and D4S180.

A novel G protein-coupled receptor kinase gene cloned from 4p16.3

Abstract: Within the Huntington's disease (HD) candidate region of 4p16.3, the D4S127 locus displays strong linkage disequilibrium with the defect and anchors a conserved haplotype found on many HD chromosomes. To isolate genes from this region we have applied the exon amplification technique to overlapping cosmids spanning D4S127. Here, we report the discovery of a new gene encoding a novel member of a family of protein kinases that specifically phosphorylate the activated forms of G protein-coupled receptors. Such kinases are thought to participate in desensitization of specific receptors, thereby blocking further signal transduction. This gene must now be carefully scrutinized to determine whether it might be involved in HD.

Characterization of a yeast artificial chromosome contig spanning the Huntington's disease gene candidate region.

Abstract: The Huntington's disease (HD) gene has been localized by recombination events to a region covering 2.2 megabases (Mb) DNA within chromosome 4p16.3. We have screened three yeast artificial chromosome (YAC) libraries in order to isolate and characterize 44 YAC clones mapping to this region. Approximately 50% of the YACs were chimaeric. Unstable YACs were identified across the whole region, but were particularly prevalent around the D4S183 and D4S43 loci. The YACs have been assembled into a contig extending from D4S126 to D4S98 covering roughly 2 Mb DNA, except for a gap of about 250 kilobases (kb). The establishment of a YAC contig which spans the region most likely to contain the HD mutation is an essential step in the isolation of the HD gene.

A recombination event that redefines the Huntington disease region

Abstract: We report both a recombination event that places the Huntington disease gene proximal to the marker D4S98 and an extended linkage-disequilibrium study that uses this marker and confirms the existence of disequilibrium between it and the HD locus. We also report the cloning of other sequences in the region around D4S98, including a new polymorphic marker R10 and conserved sequences that identify a gene in the region of interest.

DNA encoding a protein-coupled receptor kinase

Abstract: This invention relates to a DNA segment which encodes at least one member of the family of mammalian G protein-coupled receptor kinases, which maps to the Huntington's disease region within the terminal cytogenic subband of the short arm of chromosome 4, 4p163, between DNA marker D4S10 and the telomere region Further, this invention provides the substantially purified expression product of a gene from the Huntington's disease region of the chromosome, as well as related diagnostic and therapeutic uses

The alpha-subunit of the skeletal muscle sodium channel is encoded proximal to Tk-1 on mouse chromosome 11.

Abstract: Recent evidence suggests that the human neuromuscular disorders, hyperkalemic periodic paralysis and paramyotonia congenita, are both caused by genetic defects in the α-subunit of the adult skeletal muscle sodium channel, which maps near the growth hormone cluster (GH) on Chromosome (Chr) 17q. In view of the extensive homology between this human chromosome and mouse Chr 11, we typed an interspecies backcross to determine whether the murine homolog (Scn4a) of this sodium channel gene mapped within the conserved chromosomal segment. The cytosolic thymidine kinase gene, Tk-1, was also positioned on the genetic map of Chr 11. Both Scn4a and Tk-1 showed clear linkage to mouse Chr 11 loci previously typed in this backcross, yielding the map order: Tr J-(Re, Hox-2, Krt-1)-Scn4a-Tk-1. No mouse mutant that could be considered a model of either hyperkalemic periodic paralysis or paramyotonia congenita has been mapped to the appropriate region of mouse Chr 11. These data incorporate an additional locus into the already considerable degree of homology observed for these human and mouse chromosomes. These data are also consistent with the view that the conserved segment region may extend to the telomere on mouse Chr 11 and on human 17q.

Linkage, but not gene order, of homologous loci, including alpha-L-iduronidase (Idua), is conserved in the Huntington disease region of the mouse and human genomes.

Abstract: α-L-iduronidase (IDUA), which when deficient causes mucopolysaccharidosis type I, is located near the Huntington disease locus (HD) on human Chromosome (Chr) 4p16.3, approximately 106 base pairs (bp) from the telomere. As part of our continuing efforts to define a detailed comparative map for this chromosomal segment in mice and humans, we have used an interspecific backcross between C57BL/6J and an inbred strain derived from Mus spretus to map Idua, the mouse homolog of IDUA. We also mapped the mouse homolog of D4S115, an anonymous locus approximately 250 kb proximal to IDUA. As expected, both Idua and D4S115h are located on the proximal portion of mouse Chr5 near homologs for other loci on human Chr 4p. Comparison of gene order in mice and humans demonstrates, however, that a chromosomal rearrangement within this conserved synteny has occurred since divergence of lineages leading to mice and humans.