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Biomedical subjects

T Gedde-Dahl

Publications and source records attributed to T Gedde-Dahl.

At least 73 records · Page 4Linked to original sources

Hepatoblastoma and familial adenomatous polyposis.

Eleven children have been identified as having hepatoblastoma and a family history of adenomatous polyposis, and 14 additional instances of this association have been collected from the literature. Among the 11 survivors of hepatoblastoma in the combined series, adenomatous lesions have been sought in seven and detected in six patients at ages 7 to 25 years. Five of these patients also have congenital hypertrophy of the retinal pigment epithelium, a marker for carriers of the polyposis gene. These findings strengthen the association between hepatoblastoma and familial adenomatous polyposis and have led to the establishment of the Hepatoblastoma-Adenomatous Polyposis Registry.

Adenomatous Polyposis Coli↗

Restriction fragment length polymorphisms of the complement component C4 loci on chromosome 6: studies with emphasis on the determination of gene number.

Restriction fragment length polymorphisms of the C4 region of human chromosome 6 have been studied in family material where the haplotypes are defined with regard to other genetic markers in this region. Employing one near full-length C4 probe and the combination of BglII and XbaI enzymes, five different C4 genes were characterized. Studies of the segregation of DNA patterns in families made possible the reliable determination of DNA C4 haplotype pattern including gene number. In the total material of 76 haplotypes, 13 different types with regard to number and/or DNA type of C4 gene(s) were encountered. Twelve of the haplotypes had one C4 gene only, 58 had two genes, while 6 had three C4 genes. This fits fairly well with the hypothesis that the one- and three-gene haplotypes have originated through unequal crossing-over between chromosomes carrying duplicated C4 genes.

Blotting, Southern↗

VNTR (variable number of tandem repeats) markers show loss of chromosome 17p sequences in human colorectal carcinomas.

Restriction fragment length polymorphisms at 53 autosomal loci were screened for heterozygosity in 40 colorectal cancer patients. The DNA pattern in constitutional versus tumor/polyp tissue was compared. More than half of the markers tested were of the VNTR (variable number of tandem repeats) type, giving the patient panel a higher informational content, since the frequency of individuals heterozygous for a particular marker is increased. Loss of alleles was revealed in 40% of the tumors from constitutionally heterozygous patients at the chromosome 17p loci, identified by the markers YNH37 and YNZ22. Similar losses were also detected on other autosomes, but at a significantly lower frequency. Our results suggest that hemi/homozygosity of 17p alleles plays a role in the development of a major subset of colorectal carcinomas. Similar observations regarding other autosomal loci may be interpreted as random losses in these tumors, or they may indicate loci important to minor clinical subclasses of colon carcinomas.

Carcinoma↗

The Kidd (JK) blood group locus assigned to chromosome 18 by close linkage to a DNA-RFLP.

The close linkage between the PstI-restriction fragment length polymorphism (RFLP) disclosed by the L2.7 genomic DNA probe and the Kidd blood group locus is described. The maximum lod score is +8.53 at recombination fraction theta = 0.03. The upper probability limit of the recombination fraction is theta 1 = 0.11. The L2.7 probe, previously assigned provisionally to chromosome 17, is by the present study assigned to chromosome 18. This also assigns the Kidd blood group locus (JK) to chromosome 18. Accepting previous deletion mapping, the shortest regions of overlap (SRO) for JK is 18q11-12, whereas one of our hybrids assigns L2.7 to 18p11-pter, suggesting centromeric localisation of the linkage group. JK has been assigned previously to chromosome 2 because of its provisional linkage to IGK which in turn has been mapped to 2p12. Our own JK-IGK linkage data do in fact support the previous positive lod scores at high recombination fractions (total lods +4.12 at theta1 = 0.30). No obvious explanation for the conflicting gene mapping data is found.

Blood Group Antigens↗

Chromosome 13 instability and esterase D expression in an osteosarcoma cell line.

In order to assess the involvement of the 13q14 region in the development of osteosarcoma, both osteosarcoma tumor cells and normal tissue from a retinoblastoma patient previously used in restriction fragment length polymorphism studies, and sarcoma cells and normal fibroblasts from other tumor patients, have been investigated with respect to esterase D (E.C. 3.1.1.1) expression and chromosome pattern. In spite of an increased number of apparently normal chromosomes #13, a 50% reduction in esterase D activity in osteosarcoma cells from the retinoblastoma patient was observed. This suggests that loss of the RB1 gene or an OSRC gene closely linked to the ESD and RB1 gene loci is involved in the development of the osteosarcoma tumor. No reduction in esterase D expression was seen in four other sarcoma cell lines.

Carboxylesterase↗

Loss of one chromosome #13 during development of a polyposis tumor.

A cell panel from six different familial cancers, where both normal and tumor tissues were available, was examined for genotypic changes with polymorphic DNA probes. Seventeen probes were tested, representing chromosomes #1, #2, #5, #6, #13, #14, #17, and #19. One probe, p7F12 (D13S1, at 13q12-q14) revealed loss of heterozygosity in two tumors: an osteosarcoma from a patient with retinoblastoma that had been included as a control, and one polyposis tumor that had been established in nude mice from a duodenal carcinoma biopsy. Loss of heterozygosity was observed in the first passage of the mouse tumor. Chromosome analysis in later passages revealed loss of one whole chromosome #13 as the single consistent karyotypic change.

Adenomatous Polyposis Coli↗

Confirmation of the close linkage between the loci for human apolipoproteins AI and AIV by the use of a cloned cDNA probe and two restriction site polymorphisms.

We have isolated a cDNA probe for human apolipoprotein AI (apoAI) and used two DNA polymorphisms detected by this probe to analyse the inheritance of the apoAI gene in families informative for apoAIV protein variants. We have thereby increased the lod score for this linkage from 3.01 to 6.32 at a recombination fraction of zero.

Alleles↗

Gelatinase expression in generalized epidermolysis bullosa simplex fibroblasts.

The use of gelatinase expression in dermal fibroblast cultures as a marker for generalized epidermolysis bullosa simplex (D-EBS-Köbner) has been tested. None of the 6 Köbner patients tested (from 3 families) produced reduced amounts of gelatinase compared with their healthy relatives and other control groups. This shows that a reduced production of gelatinase from dermal fibroblasts is not uniformly a marker for D-EBS-K.

Epidermolysis Bullosa↗

The C8A and C8B loci are closely linked on chromosome 1.

Close linkage was demonstrated between the loci governing the polymorphisms of complement component C8 alpha-gamma (C8A) and beta (C8B). Both C8 loci were linked to the chromosome 1 marker loci PGM1 and Rh. The distance between the two C8 loci and PGM1 appeared identical in males and females. A female/male ratio of 1.6 was observed between the two C8 loci and Rh. No evidence for linkage between the C8 loci and Fy was found. Preliminary results of this study were presented at the Eighth International Workshop on Human Gene Mapping, Helsinki, August 1985 (Rogde et al. 1985b).

Chromosomes, Human, Pair 1↗

Very close linkage between D2S1 and ACP1 on chromosome 2p.

The genomic DNA-probe L2.30 was used to assign D2S1 to 2p23-pter by in situ hybridization. The RFLP revealed by BglII was then used for linkage studies in the Oslo-NHIK families segregating for the acid phosphatase ACP1 protein polymorphism. Evidence for very close linkage was found by a lod score of +17.17 at recombination fraction theta = 0.01. By this close linkage 92 informative meioses could be inferred from the families and with only a single crossover. The upper probability limit to the recombination fraction is 0.06 according to the HGM 8 criterion. No association between ACP1 alleles and D2S1 BglII alleles was found. The Norwegian gene frequencies for D2S1 were A1 (9.0 kb) = 0.65 and A2 (6.3 kb) = 0.35.

Acid Phosphatase↗

Testicular neoplasms occurring in four brothers. A search for a genetic predisposition.

Four brothers who developed testicular neoplasms, one bilaterally, are described. Histologic examination showed four of the tumors to be seminomas and one to be a mixed germ cell tumor. Three of the brothers are alive. Apart from a late-onset bladder carcinoma in their father and a pulmonary cancer in a maternal uncle, cancers were not recorded in the extended kindred. One patient, a sister, and the parents had normal frequency of sister chromatid exchange (SCE) and chromosome aberrations, whereas the two patients sampled after radiation showed increase in one or both. The father was found heterozygous in 12 and the mother in 8 genetic marker systems among 25 tested. For the blood group gene loci JK and MNSs, and the erythrocyte enzyme locus GPT the father had given the same allele to all three affected sons examined. The mother had given different alleles to the sons in all of her informative markers. On the model of a recessively acting susceptibility gene, only JK and GPT remained consistent with linkage without recombination. These investigations did not add support to a genetic etiology for the unusual family occurrence of testicular cancer. An apparent birth-order effect on time at onset/diagnosis in this and published families suggests time-limited environmental factors. Nevertheless, JK, MNSs, and GPT should be included in future testis cancer families to test the model of a "dominant" genetic predisposition.

Adult↗