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Biomedical subjects

B Arveiler

Publications and source records attributed to B Arveiler.

48 records · Page 3Linked to original sources
PubMed1987

Close linkage of random DNA fragments from Xq 21.3-22 to X-linked agammaglobulinaemia (XLA).

Linkage analysis of 15 families affected by X-linked agammaglobulinaemia (XLA) showed close linkage with three probes located towards the centre of the long arm of the X chromosome. No cross-overs were found using pXG12 (DXS94) lod 6.6 or S21 (DXS17) lod 4.4. One cross-over was found with 19.2 (DXS3). This confirms and extends a previous linkage study (Kwan et al. 1986) which demonstrated linkage with S21 and 19.2. Of the families 14 were informative for either pXG12 or S21 and these probes should thus be of great diagnostic value. No evidence of heterogeneity was found in the XLA families but several cross-overs within this region were detected in a family with the X-linked hyper-IgM syndrome confirming this disease as a separate clinical entity.

Agammaglobulinemia↗
PubMed1987

Multipoint genetic mapping of the Xq26-q28 region in families with fragile X mental retardation and in normal families reveals tight linkage of markers in q26-q27.

The q26-q28 region of the human X chromosome contains several important disease loci, including the locus for the fragile X mental retardation syndrome. We have characterized new polymorphic DNA markers useful for the genetic mapping of this region. They include a new Bell restriction fragment length polymorphism (RFLP) detected by the probe St14-1 (DXS52) and which may therefore be of diagnostic use in hemophilia A families. A linkage analysis was performed in fragile X families and in large normal families from the Centre d'Etude du Polymorphisme Humain (CEPH) by using seven polymorphic loci located in Xq26-q28. This multipoint linkage study allowed us to establish the order centromere-DXS100-DXS86-DXS144-DXS51-F9-FRAX+ ++-(DXS52-DXS15). Together with other studies, our results define a cluster of nine loci that are located in Xq26-q27 and map within a 10 to 15 centimorgan region. This contrasts with the paucity of markers (other than the fragile X locus) between the F9 gene in q27 and the G6PD cluster in q28, which are separated by about 30% recombination.

Chromosome Mapping↗
PubMed1987

Genetic mapping of nine DNA markers in the q11----q22 region of the human X chromosome.

We have ordered nine polymorphic DNA markers within detailed map of the proximal part of the human X chromosome long arm, extending from band q11 to q22, by use of both physical mapping with a panel of rodent-human somatic hybrids and multipoint linkage analysis. Analysis of 44 families (including 17 families from the Centre d'Etude du Polymorphisme Humain) provided highly significant linkage data for both order and estimation of map distances between loci. We have obtained the following order: DXS1-DXS159-DXYS1-DXYS12-DXS3-(DXS94 , DXS178)-DXYS17. The most probable location of DXYS2 is between DXS159 and DXS3, close to DXYS1 and DXYS12. The high density of markers (nine loci within 30 recombination units) and the improvement in the estimation of recombination frequencies should be very useful for multipoint mapping of disease loci in this region and for diagnostic applications.

Chromosome Banding↗
PubMed1987

Close linkage of the locus for X chromosome-linked severe combined immunodeficiency to polymorphic DNA markers in Xq11-q13.

The gene for X chromosome-linked severe combined immunodeficiency (SCID), a disease characterized by a block in early T-cell differentiation, has been mapped to the region Xq11-q13 by linkage analysis with restriction fragment length polymorphisms. High logarithm of odds (lod) scores were obtained with the marker 19.2 (DXS3) (z = 5.51 at a recombination fraction theta = 0.11) and with the marker cpX73 (DXS159) that showed complete cosegregation with the disease locus in the informative families analyzed (z = 5.27 at theta = 0.00). Other significant linkages were obtained with several markers from Xq11 to q22. With the help of a recently developed genetic map of the region, it was possible to perform multipoint linkage analysis, and the most likely genetic order is DXS1-(SCID, DXS159)-DXYS1-DXYS12-DXS3, with a maximum multipoint logarithm of odds score of 11.0. Our results demonstrate that the SCID locus (gene symbol IMD4) is not closely linked to the locus of Bruton's agammaglobulinemia (a defect in B-cell maturation). They also provide a way for a better estimation of risk for carrier and antenatal diagnosis.

Female↗
PubMedDate not supplied

Linkage analysis suggests at least two loci for X-linked non-specific mental retardation.

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.

Chromosome Mapping↗
PubMedDate not supplied

Improved DNA markers for efficient analysis of fragile X families.

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.

DNA Probes↗
PubMedDate not supplied

Analysis of deletions in DNA from patients with Becker and Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder for which the biochemical defect is as yet unknown. Recently, two cloned segments of human X-chromosome DNA have been described which detect structural alterations within or near the genetic locus responsible for the disorder. Both of these cloned segments were described as tightly linked to the locus and were capable of detecting deletions in the DNA of boys affected with DMD. In an attempt to determine more precisely the occurrence of these deletions within a large population of DMD patients and the accuracy of one of the segments, DXS164 (pERT87), in determining the inheritance of the DMD X chromosome, the subclones 1, 8 and 15 were made available to many investigators throughout the world. Here we describe the combined results of more than 20 research laboratories with respect to the occurrence of deletions at the DXS164 locus in DNA samples isolated from patients with DMD and Becker muscular dystrophy (BMD). The results indicate that the DXS164 locus apparently recombines with DMD 5% of the time, but is probably located between independent sites of mutation which yield DMD. The breakpoints of some deletions are delineated within the DXS164 locus, and it is evident that the deletions at the DMD locus are frequent and extremely large.

Chromosome Deletion↗
PubMedDate not supplied

Familial aggregation of vitiligo in the French West Indies (Isle of Martinique).

Environmental factors are thought to influence the genetic transmission of vitiligo, and may change in families of different extraction. Most studies on vitiligo have been performed in occidental countries or in India, therefore, our purpose was to study the familial vitiligo aggregation in Martinique (French West Indies). Data on 16 families were collected from 1995 to 1999. Information was compared to 36 controls affected with sporadic vitiligo, using the chi(2) test. The prevalence among relatives of patients was 7%, as compared to 0.34% in the general population (p < 0.001). The age of onset of vitiligo was 31 in family cases and 33 in controls. Vitiligo occurred before the age of 20 in 19% of family cases and in 36% of controls. Most families (75%) have no more than 2 affected members. No difference was observed in triggering and environmental factors in family cases and controls. Our observations are in agreement with the literature data, leading to the assumption that the environmental factors involved in the expression of vitiligo in our island do not differ from other areas.

Adolescent↗