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Biomedical subjects

A Gal

Publications and source records attributed to A Gal.

260 records · Page 15Linked to original sources
PubMedDate not supplied

XLMR genes: update 1990.

We have identified 39 X-linked conditions in which mental retardation seems to be the primary characteristic, although pathogenesis is unknown. These conditions can be subdivided into syndromal and non-syndromal, depending on the existence of a recognizable pattern of minor anomalies and/or malformations, or lack thereof. Seventeen genes have been regionally mapped onto the X chromosome. However, in 14 instances the data were derived from a single family and most lod scores were less than 3.0.

Chromosome Mapping↗
PubMedDate not supplied

Gene for non-specific X-linked mental retardation maps in the pericentromeric region.

Linkage analysis was carried out in a large four-generation German family segregating for non-specific X-linked mental retardation. Affected males have moderate intellectual handicap. Speech delay, deviant behaviour, and hyperactivity have also been reported. Head circumference and testicular volumes are normal. Cytogenetic analysis failed to show evidence for fragile site or structural abnormality of the X chromosome. None of the obligatory carriers shows any clinical symptoms. Close linkage without recombination (lod scores 1.74 to 2.05) has been found between the disease locus (MRX1) and the polymorphic DNA loci DXS7 (Xp11.4-p11.3), MAOA (Xp11.3-p11.23), DXS255 (Xp11.22), and DXS159 (Xq12) suggesting that the gene responsible for the disease in this family maps in the pericentromeric region of the X chromosome. Linkage data obtained with the flanking marker loci OTC (Xp21.1) and DXS95 (Xq21.2-q21.3) also were compatible with this localization of the MRX1 gene. Close linkage to loci from Xp22, Xq22, Xq24-25, or Xq28 could be excluded.

Adult↗
PubMedDate not supplied

Gene localization in a family with X-linked syndromal mental retardation (Prieto syndrome).

A mapping study was performed on a 3-generation Spanish family with X-linked syndromal mental retardation. Affected males have a typical facial appearance, ear malformations, abnormal growth of teeth, clinodactyly, dimpled skin at the lower back, and patellar luxation. In pneumoencephalography a marked subcortical cerebral atrophy was evident. In the linkage studies with polymorphic DNA markers, no recombination was found between the disease locus and the loci OTC and DXS148, both assigned to Xp21.1. One or more recombinants were observed between the disease locus and loci from the distal part of Xp and the pericentromeric region. Close linkage to loci of Xq has also been excluded. The analysis of multiple informative meioses suggests that the disease locus maps between DXS255 (Xp11.22) and DXS84 (Xp21.1) on Xp.

Abnormalities, Multiple↗
PubMedDate not supplied

Homologous nonallelic recombinations between the iduronate-sulfatase gene and pseudogene cause various intragenic deletions and inversions in patients with mucopolysaccharidosis type II.

About 20% of patients with mucopolysaccharidosis type II (MPS II) have gross structural rearrangements involving the iduronate-sulfatase (IDS) gene in Xq27.3-q28. A nearby IDS pseudogene (IDS-2) promotes nonallelic recombination between highly homologous sequences. Here we describe major rearrangements due to gene/pseudogene recombination. In two unrelated patients, partial IDS gene deletions were found joining introns 3 and 7 of the IDS gene together with gene to pseudogene conversion in the area of breakpoints. In a third patient, a junction between intron 3 of IDS-2 and intron 7 of IDS was seen that was due to a deletion and inversion of the 5' part of the gene. Characterisation of breakpoints in six patients with large inversions revealed that all recombinations of this type occurred in the same area of homology between IDS and IDS-2; they were molecularly balanced, and accompanied by gene conversions in most cases. Apart from diagnostic implications, such naturally occurring recombination 'hot spots' may allow some insight into general features of crossover events in mammals.

Alleles↗
PubMedDate not supplied

Residual neurobehavioral impairment in a water technician exposed to hydrazine-containing mixtures.

Residual neurobehavioral impairment in concentration, comprehension, memory, task performance and mood status persisted in a water technician with respiratory and dermal exposures to hydrazine-containing mixtures prior to treatment with steroids for concurrent thrombocytopenia. The findings call attention to the possibility that residual neurobehavioral impairment may be an effect of exposure to hydrazine mixtures.

Adult↗