Biomedical subjects

J Weissenbach

Publications and source records attributed to J Weissenbach.

349 records · Page 20Linked to original sources

PubMedDate not supplied

Chromosome Y-specific DNA in related human XX males.

Human 'XX males' are sterile males whose chromosomes seem to be those of a normal female. About 1 in 20,000 males has a 46, XX karyotype, and most cases are sporadic, that is, they are without familial clustering. It has long been argued that maleness in XX males may result from the undetected presence of a small, testis-determining fragment of the Y chromosome, and there is strong evidence for this in sporadically occurring XX males. Indeed, the genomes of three of four sporadic XX males tested were found to contain certain Y-specific DNA sequences. A pedigree in which three XX males occur has been interpreted as being consistent with autosomal recessive inheritance of maleness, and it has been argued that the basis of XX maleness in this family is fundamentally different from that in the sporadic cases. However, we report here that these related XX males, like the sporadic cases, contain portions of the Y chromosome. The portion of the Y chromosome present in one of the three XX males differs from that present in the other two.

Chromosome Mapping↗

PubMedDate not supplied

Pseudoautosomal DNA sequences in the pairing region of the human sex chromosomes.

A DNA probe from a human Y chromosome-derived cosmid detects a single-copy genomic DNA fragment which can appear in different allelic forms shared by both sex chromosomes. Variants at this DNA locus show an autosomal pattern of inheritance, undergo recombination with sexual phenotype and can therefore be described as 'pseudoautosomal'. Another probe from the same cosmid detects a sequence repeated 15-20 times per haploid genome. These repeats also appear pseudoautosomal and map exclusively to the short-arm terminal region of each sex chromosome.

Chromosome Mapping↗

PubMedDate not supplied

A gradient of sex linkage in the pseudoautosomal region of the human sex chromosomes.

Three independent pseudoautosomal loci are linked to sex determination at frequencies which define a gradient of linkage. The segregation patterns of these loci indicate that X/Y recombination results from a single obligatory meiotic crossing-over in the pseudoautosomal region. Recombination in male germ cells in the terminal regions of the short arms of the X and Y chromosomes in 10-fold greater than between the same regions of the X chromosomes in female germ cells.

Animals↗

PubMedDate not supplied

A sensorineural progressive autosomal recessive form of isolated deafness, DFNB13, maps to chromosome 7q34-q36.

Deafness is the most frequent sensorineural defect in children. The vast majority of the prelingual forms of isolated deafness are highly genetically heterogeneous with an autosomal recessive mode of inheritance. Using linkage analysis, we have mapped the gene responsible for a severe progressive sensorineural hearing loss, DFNB13, segregating in a large consanguineous family living in an isolated region in northern Lebanon. A maximum lod score of 4.5 was detected for markers D7S661-D7S498. Recombination events and homozygosity mapping by descent define a 17 cM gene interval in the chromosome region 7q34-q36, between the markers D7S2468/D7S2505, on the proximal side, and D7S2439, on the distal side.

Chromosome Mapping↗

PubMedDate not supplied

Genetic linkage of Meleda disease to chromosome 8qter.

Meleda disease (mal de Meleda) MIM *248300 is an autosomal recessive disorder, clinically characterised by transgressive palmoplantar keratoderma, hyperhidrosis and perioral erythema. It was first described on the Adriatic island of Meleda, where it was relatively common. The prevalence in the general population is estimated to be 1 in 100,000. Linkage analysis of two large consanguineous families from Algeria, including 10 affected individuals, showed strong evidence for localisation of Meleda disease to chromosome 8qter with a maximum two-point lod score for D8S1751 of 8.21 at theta = 0. Analysis of homozygosity regions and recombination events places the gene in a region of at least 3 cM, telomeric to D8S1727. A common haplotype was observed in the two families, suggesting a founder effect.

Chromosomes, Human, Pair 8↗

PubMedDate not supplied

Nephropathic cystinosis (CTNS-LSB): construction of a YAC contig comprising the refined critical region on chromosome 17p13.

A yeast artificial chromosome (YAC) contig was constructed encompassing the entire region on chromosome 17p13 where the autosomal recessive disorder infantile nephropathic cystinosis (MIM 21980, CTNS-LSB) has been genetically mapped. It comprises seven clones ordered by their content of a series of six sequence-tagged sites (STSs). Fluorescence in situ hybridisation (FISH) revealed two chimaeric clones. The order of four polymorphic STSs mapped with the contig was consistent with that of the known genetic map with the exception of markers D17S1583 (AFMb307zg5) and D17S1798 (AFMa202xf5) where a telomeric location of D17S1583 was inferred from the contig; two non-polymorphic STSs were localised within the marker frame-work. From the analysis of recombination events in an unaffected individual as defined by leucocyte cystine levels we support the high-resolution mapping of this region to a small genetic interval and show that it is entirely represented on a single, non-chimaeric YAC clone in the contig.

Chromosome Mapping↗

PubMedDate not supplied

Mapping of Papillon-Lefevre syndrome to the chromosome 11q14 region.

Papillon-Lefevre syndrome (PLS) is an autosomal recessive disease which belongs to the palmo-plantar keratoderma (PPK) group. It is characterized by a premature loss of primary and permanent teeth and early onset periodontitis. High consanguinity has been observed in over one-third of PLS families. No candidate genes or gene localizations have been described to date for this disorder. A primary genome-wide search by homozygosity mapping using samples from a large consanguineous family in which 4 siblings were affected by the disease showed homozygosity and linkage in the region of 11q14. Linkage was confirmed in 4 additional families with diverse ethnic and geographic backgrounds, 2 of which were consanguineous. A maximum two-point lod score of 8.19 was obtained for the marker AFM063yg1 (D11S901= for theta = 0. Analysis of recombination events places the gene within a 7-cM interval between AFM063yg1 and AFM269yg9 (D11S4175). No shared haplotype was found for the 5 families analysed.

Chromosome Mapping↗