Search PubMed⌕ Search

Biomedical subjects

V Allamand

Publications and source records attributed to V Allamand.

27 records · Page 2Linked to original sources

Mapping of a chromosome 15 region involved in limb girdle muscular dystrophy.

A gene responsible for an autosomal recessive form of limb girdle muscular dystrophy (LGMD2, MIM number 253600) has been localized on chromosome 15. After genotyping additional markers of this chromosome, two were found to flank the disease locus within an interval that was assessed as 7 centiMorgans. The screening of the CEPH YAC libraries with the corresponding probes allowed the isolation of YACs which were used in fluorescence in situ hybridization to define the LGMD2 cytogenetic interval as 15q15.1-15q21.1. Four different approaches were pursued for the establishment of the physical map of this area which allowed the assembly of an uninterrupted YAC contig spanning an estimated 10-12 megabases, with an average STS resolution of 140 kb or for the 25 polymorphic microsatellites on this map, of 400 kb. Twelve genes and 25 genetic markers were positioned in this contig, which is constituted of a minimum of 10 clones.

Chromosome Mapping↗

Autosomal dominant retinitis pigmentosa (adRP; RP6): cosegregation of RP6 and the peripherin-RDS locus in a late-onset family of Irish origin.

We recently reported the localization of a gene for late-onset autosomal dominant retinitis pigmentosa (adRP; RP6), on the short arm of chromosome 6, by linkage analysis in a large family of Irish origin. It is notable that the gene encoding peripherin-RDS, a photoreceptor-specific protein, recently has been physically mapped on 6p. In our own analysis, an intrageneic marker derived from this gene cosegregated with the adRP disease locus with zero recombination (lod score 5.46 at q = .00). Using the CEPH reference panel, we now report the mapping of the peripherin-RDS gene relative to other 6p markers in the CEPH data base. Incorporation of these data into a multipoint analysis produced a lod score for adRP of 8.21, maximizing at the peripherin-RDS locus. This study provides strong evidence suggesting a role for peripherin-RDS in the etiology of one form of adRP.

Base Sequence↗

Autosomal dominant retinitis pigmentosa: localization of a disease gene (RP6) to the short arm of chromosome 6.

DNA from members of an Irish pedigree presenting with late onset autosomal dominant retinitis pigmentosa (ADRP) have been typed with a series of genetic markers from chromosome 6p. Positive two-point lod scores have been obtained with five markers (D6S89: theta = 0.10, Z = 3.338; D6S109: theta = 0.10, Z = 3.932; D6S105: theta = 0.00, Z = 6.081; HLA-DRA: theta = 0.00, Z = 4.364; and RDS: theta = 0.00, Z = 5.376). In a series of overlapping multipoint analyses a lod score of 6.6 was obtained, maximizing at HLA-DRA and hence localizing the ADRP gene (RP5) segregating in this pedigree to 6p. These data provide direct evidence for an additional autosomal dominant RP locus and strongly implicate the human equivalent of the mouse retinal degeneration slow (rds) gene, peripherin-rds, as a candidate for autosomal dominant retinitis pigmentosa.

Base Sequence↗

Limb girdle muscular dystrophy type 2A (CAPN3): mapping using allelic association.

Recently a graphical study of linkage disequilibrium around the CAPN3 locus failed to refine the 1.3-Mb interval suggested by haplotype sharing. On the contrary, the Malecot model as implemented in the ALLASS program maps CAPN3 within 3 kb of its true location (23 kb from the locus midpoint), overcoming identified problems with small samples, interrelated sibships, and short duration.

Alleles↗