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S Luscombe

Publications and source records attributed to S Luscombe.

4 recordsLinked to original sources

U-type exchange in a paracentric inversion as a possible mechanism of origin of an inverted tandem duplication of chromosome 8.

A mentally retarded male with dysmorphic features was found to have a de novo 46,XY,inv dup(8) (p.23.1-->12). Confirmation of the segments duplicated in the rearrangement was achieved by biochemical analysis of glutathione reductase, which maps to 8p21.1, and DNA studies using the chromosome specific probe y-19-1D (D85131), which maps to 8p21. Assay of cathepsin B, which has been localised to 8p22, did not differ from controls with normal chromosomal constitution. DNA studies using the Defensin 1 gene probe, which maps to 8p23, showed a previously undetected deletion of that segment. We propose that the inverted tandem duplication/deletion arose as a single U-type exchange within an inversion loop.

Abnormalities, Multiple↗

Newborn screening for sickle cell and other hemoglobinopathies: a Canadian pilot study.

We estimated incidence of HbS disease in Quebec. It is approximately 9 cases per 100,000 births (equivalent to the incidence of the hyperphenylalanemias). Accordingly, we performed a voluntary pilot study in 9 self-identified ethnic groups; 3528 families were counselled about the relevance of newborn screening for hemoglobinopathies; and 2779 cord blood samples were collected (participation rate, 78.7%) and analyzed for Hemoglobin S and other hemoglobin variants by cellulose acetate electrophoresis. There were 95 (3.42%) positive tests on the initial (cord blood) samples, of which only 40 could be confirmed because of low participation in follow-up. We identified 8 false-positive tests; 7 had been classified initially as alpha-thalassemia trait and one as HbC heterozygosity on the first test. The relative frequency of hemoglobinopathy genes (confirmed) was: 52.5% HbS; 22.5% alpha-thalassemia; 22.5% other mutation; all but one patient with sickle cell disease were heterozygotes; the majority (71%) of HbS genes were accounted for by the 7% of screened newborns who were Black; a further 24% of the HbS genes were accounted for by 7% with Central American ancestry. Record linkage of the findings in heterozygotes for use later in life is an unsolved problem. Seventy five first-degree relatives of the 48 probands were screened in follow-up studies (64% of parents participated); 5 couples at risk for having a future child with a hemoglobinopathy were identified. Attitudes toward follow-up varied among the ethnic groups. The single family with an affected newborn (sickle cell anemia) was counselled effectively; the infant received penicillin prophylaxis.(ABSTRACT TRUNCATED AT 250 WORDS)

Anemia, Sickle Cell↗

Internal proteins of influenza virus: 35S-methionine peptide maps as genetic markers.

Methods are described for the preparation in vivo of 35S-methionine-labelled influenza viruses, the purifiction of the nucleoprotein (NP) and matrix (M) proteins and the separation of peptides obtained by protease digestion by two-dimensional thin-layer chromatography. The maps of the M proteins of A/Okuda/57(H2N2) and A/Finland/4/74(H3N2) were very similar overall but differed in three peptides. Hence they could be clearly distinguished. Maps of the NP proteins of the same strains showed a greater number of differences. A recombinant strain having the haemagglutinin and neuraminidase of the A/Finland/4/74 parent and the virulence of the A/Okuda/57 parent was shown to have the M and P proteins of A/okuda/57.

Chromosome Mapping↗