Showing papers by "Jean-Louis Mandel published in 1988"
TL;DR: The breakage events described here for the X chromosome should provide a minimal estimate for the frequency of chromosomal rearrangement events, such as breakage and inversion, which have affected autosomal synteny groups during the evolutionary period separating man from mouse.
60 citations
TL;DR: In this article, the authors performed linkage analysis in three families and found that at least two non-specific XLMR loci could exist, one in Xp22 and the other in the q12-q13 region.
Abstract: Epidemiological studies have suggested that non-specific X-linked mental retardation (XLMR) might be at least as frequent as the fragile X syndrome. The identification of all mutations causing XLMR would thus appear of prime importance. In the absence of other clinical signs the problem of genetic heterogeneity is acute. This can be partly overcome by the analysis of large families. We have been able to perform linkage analysis in 3 such families. The condition in family 1 was described as clinically resembling the fra (X) syndrome by Proops et al [1983]: the kindred includes 7 affected males in 3 sibships. Family 2 from Denmark has affected males in 4 generations; however, several affected relatives in this extended pedigree are deceased. Family 3 from France counts 6 affected males in two sibships. The families were analysed with about 25 X-linked markers. Linkage with markers in Xp22.2-p22.3 was found in family 1: z(theta) = 2.62 at theta = 0.06 for DXS85 (probe 782). Suggestion of linkage was found in family 2 with both the Duchenne muscular dystrophy region (DXS164 in Xp21.2) and with DXS1 (Xq11-q12). In family 3, DXS159 (Xq12-q13) gave a lod score of 2.53 at theta = 0; results were compatible with localisation of the putative XLMR locus in this family proximal to DXYS1 (Xq21). These data suggest that at least two non-specific XLMR loci could exist, one in Xp22 and the other in the q12-q13 region.
51 citations
TL;DR: The families as a whole showed genetic heterogeneity for linkage between F9 and fra(X), and the best multipoint distances were found to be DXS51-F9 and DXS52-DXS15.
Abstract: A multilocus analysis of the fragile X (fra(X)) syndrome was conducted with 147 families. Two proximal loci, DXS51 and F9, and two distal loci, DXS52 and DXS15, were studied. Overall, the best multipoint distances were found to be DXS51-F9, 6.9%, F9-fra(X), 22.4%; fra(X)-DXS52, 12.7%; DXS52-DXS15, 2.2%. These distances can be used for multipoint mapping of new probes, carrier testing and counseling of fra(X) families. Consistent with several previous studies, the families as a whole showed genetic heterogeneity for linkage between F9 and fra(X).
50 citations
TL;DR: A 5-point linkage analysis with many X-linked RFLP markers in 4 families of Coffin-Lowry syndrome found positive two-point lod scores with DXS28 and DXS41, and a multipoint lod score of 3.41 for a localisation in Xp22.2-p 22.1, between DXS43 andDXS41.
Abstract: The Coffin-Lowry syndrome (McKusick No. 30360) is a rare genetically transmitted disorder characterized by severe mental retardation, "coarse" facial appearance, thick soft skin, tapering fingers, and progressive skeletal abnormalities. X-linked inheritance is implied since the males are severely affected with variably mild manifestations in carrier women. We have performed a linkage analysis with many X-linked RFLP markers in 4 families. Positive two-point lod scores were obtained with DXS28 (z(theta) = 2.00 at theta = 0.05) and DXS41 (z(theta) = 1.26 at theta = 0.10). We performed a 5-point linkage analysis using the LINKMAP program assuming that DXS16 and DXS43 are a single locus and using the following fixed map (distances in centimorgans): DXS85 - 18cM - (DXS16, DXS43) - 13cM - DXS41 - 5cM -DXS28. This gave a multipoint lod score of 3.41 for a localisation in Xp22.2-p22.1, between DXS43 and DXS41.
47 citations
TL;DR: The characteristics of two new probes that detect BclI RFLPs useful for analysis of fragile X families and 34% of women are heterozygous both for the proximal marker DXS105 and for the distal markers DXS52 or the factor VIII gene are reported.
Abstract: We report the characteristics of two new probes that detect BclI RFLPs useful for analysis of fragile X families. With these two probes and a single blot, 34% of women are heterozygous both for the proximal marker DXS105 (closer to the fragile X locus than the factor IX gene) and for the distal markers DXS52 or the factor VIII gene. Combined with the analysis of previously described polymorphic markers, it is possible to have a majority of families fully informative for flanking markers using a limited number of probes and restriction digests.
37 citations
TL;DR: A DNA fragment is isolated that hybridizes to six further homologous X-specific genomic fragments that map to at least four different regions of the human X chromosome that is present with the same complexity and X specificity in macaques whereas no related sequences were detected in the mouse.
21 citations
TL;DR: Physical mapping places DSX159 proximal to the Xq12 breakpoint of an X autosome translocation found in a female with clinical signs of ectodermal dysplasia, which would appear the closest on the proximal side of the disease locus.
Abstract: Three families with anhidrotic ectodermal dysplasia (AED) have been studied by linkage analysis with seven polymorphic DNA markers from the Xp11-q21 region. Previously reported linkage to DXYS1 (Xq13-q21) has been confirmed (z(θ)=4.08 at θ=0.05) and we have also established linkage to another polymorphic locus, DXS159, located in Xq11-q12 (z(θ)=4.28 at θ=0.05). Physical mapping places DSX159 proximal to the Xq12 breakpoint of an X autosome translocation found in a female with clinical signs of ectodermal dysplasia. Of all markers that have been used in linkage analysis of AED, DXS159 would appear the closest on the proximal side of the disease locus.
14 citations
TL;DR: Two restriction fragment length polymorphisms (RFLP) are described that should be of use in linkage or population studies to test a possible involvement of the BCEI gene in genetic predisposition to breast cancer.
Abstract: The BCEI gene codes for a small secreted protein and is expressed in the human mammary tumour cell line MCF7 under oestrogen control and in some breast cancers. We have mapped the gene to chromosome 21 using a panel of somatic hybrid lines, and in situ hybridization has allowed a precise assignment to band 21q223. Two restriction fragment length polymorphisms (RFLP) are described that should be of use in linkage or population studies to test a possible involvement of the BCEI gene in genetic predisposition to breast cancer. This gene should also be a useful marker for the genetic and physical mapping of chromosome 21, and for a better definition of the region involved in the clinical phenotype of Downs syndrome.
12 citations
TL;DR: Most of the sequence was determined on at least two independent clones and sequence variants which might be due either to polymorphism or to cloning artefacts are presented in the table.
Abstract: Dystrophln cONA clones were isolated from a library constructed with poly A* RNA from leg muscle of 13 days old chicken (1). The sequence of 13575 base pairs contains an open reading frame beginning with ATG at nucleotide 151 and ending with TAG at nucleotide 11131, and encodes a 3660 amino acid protein (1). The 3 untranslated sequence (2442 nucleotides) does not contain the polyadenylation signal and may lack only about 50 nucleotides as shown by alignment with the human sequence (2). A previously sequenced exon (3) and two incompletely spliced cONA clones allow us to place exon limits at position 811-812, 993-994, 5310-5311, 8013-8014 (exon-1ntron junction sequence for the two last exons is given 1n the figure). Most of the sequence was determined on at least two independent clones (1). Sequence variants which might be due either to polymorphism or to cloning artefacts are presented in the table.
12 citations
TL;DR: The human retinoic acid receptor (hRAR) gene has been mapped in 17q21 by in situ hybridization (2) and invariant bands are detected under medium stringency conditions.
Abstract: POLYMORPHISM: PstI identifies a two allele polymorphism with bands at 3.0 kb (PI) or 2.6 kb + 0.4 kb (P2). Under medium stringency conditions (see below), invariant bands are detected at 5. CHROMOSOMAL LOCALISATION: The human retinoic acid receptor (hRAR) gene has been mapped in 17q21 by in situ hybridization (2).
6 citations