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E Niebuhr

Publications and source records attributed to E Niebuhr.

At least 19 recordsLinked to original sources
PubMed1992

[Preclinical and prenatal diagnosis of familial adenomatous polyposis].

In order to investigate the possibility of preclinical and prenatal genetic diagnosis of familial adenomatous polyposis (FAP) by means of DNA-systems and other markers, blood samples were collected from 246 persons in 29 families, including 90 with the clinical diagnosis FAP and 73 clinically unaffected first degree relatives (persons at risk). The material was studied with up to 4 DNA-marker systems located in the region around the disease gene. Among the first degree relatives eight (11%) had probably inherited the disease gene, while 31 persons (42%) in this risk group had probably not inherited the gene. It was not possible to evaluate the risk in the remaining 34 persons (47%). In 45 (85%) out of 53 persons under 40 years the DNA-systems were informative, so that it would be possible to offer the option of prenatal diagnosis. It is concluded that preclinical and possibly prenatal genetic diagnosis may be offered; but the current practice of prophylactic proctosigmoidoscopic surveillance should be maintained.

Adenomatous Polyposis Coli↗
PubMed1991

Sister-chromatid exchanges in cannabis smokers.

The genotoxicity of cannabis smoking was evaluated by means of the sister-chromatid exchange (SCE) test. The SCE test is considered to be a sensitive tool for the discovery of genotoxic agents in the environment. Twenty-two tobacco smokers and 22 persons smoking both tobacco and cannabis were compared. Our findings showed that smoking in itself enhanced the SCE level significantly (18.5%) compared to a group of non-smokers, but adding smoking of cannabis to tobacco smoking did not affect the SCE level further. Based on our observations cannabis smoking could not be considered genotoxic.

Adolescent↗
PubMed1990

Parental origin of chromosome 5 deletions in the cri-du-chat syndrome.

The parental origin of de novo deletions leading to the cri-du-chat syndrome has been investigated. Since the cri-du-chat syndrome is correlated with deletions involving the short arm of chromosome 5 (5p), DNA fragments known to detect restriction fragment length polymorphisms (RFLPs) along 5p were used to establish whether the paternal or the maternal chromosome had suffered the deletion. In cases where only one parent was available, somatic cell hybrids were used in conjunction with RFLP analysis to determine the origin of the deleted chromosome. The deleted chromosome 5 was of paternal origin in 20/25 cases.

Chromosome Deletion↗
PubMed1990

A deletion panel of the long arm of the X chromosome: subregional localization of 22 DNA probes.

Two males and two females with different but overlapping deletions on the proximal long arm of the X chromosomes have been investigated. Their karyotypes, which have been well characterized by high resolution banding techniques, are 46,Y,del(X)(pter----q21.1::q21.33----qter); 46,Y,del(X)(pter----q21.2::q21.31----qter); 46,X,del(X)(pter----q21.31::q24.3----qter) and 46,X,del(X)(pter----q21.1:). A deletion panel, which makes it possible to subdivide the long arm of the X chromosome into seven subregions, has been established using the genomic DNA from the four families, and applied to the fine subregional localization of the loci for 22 DNA probes. Based on the results obtained, the possible location of the loci in question has been narrowed down considerably, in some cases to an area of only 5% of the previously assigned region; hybridization to Southern blots of a panel with well-characterized chromosome deletions is thus a powerful means of localizing DNA probes, especially with respect to the X probes.

Blotting, Southern↗
PubMed1990

DXS26 (HU16) is located in Xq21.1.

We have localized a single-copy DNA probe, HU16 (locus DXS26), to Xq21.1. The probe was isolated from a human-mouse hybrid X;13 library and mapped with human-mouse hybrids containing different portions of the human X chromosome and DNA from male patients with different X-chromosomal deletions. The following order of loci is proposed: Xcen-(DXS72,DXS169)-(DXS232,DSX26)-DXS1 21-DXS233-DXS165-TCD-DXS95-DXYS1-Xqter. HU16 will be useful in the study of the putative genes that reside in Xq21 and whose defects lead to deafness and mental retardation.

Animals↗
PubMed1990

5p;12q translocation with manifestations of cri du chat syndrome and Marfanoid arachnodactyly.

A 12-year-old boy with a history of a mewing cry after birth, severe mental retardation, Marfanoid arachnodactyly, general osteomalacia and multiple bone fractures was found to have a de novo 5p;12q chromosomal translocation. The karyotype is 46,XY,t(5;12)(12qter----12q24.1::5p15----cen----5qt er; 12pter----cen----12q24.1). The karyotypes of other examined family members are normal. The manifestations of cri du chat syndrome are explained by the loss of a small segment of 5p15 which is responsible for the major stigmata of the syndrome, and the abnormalities of the osseous system may be the results of untreated vitamin D resistant rickets.

Child↗
PubMed1990

Exclusion mapping of 12 X-linked disease loci and 10 DNA probes from the long arm of the X-chromosome.

Specific chromosome rearrangements associated with disease entities are invaluable resources for physical mapping. A deletion on the X chromosome of a male leads to the nullisomy for X-linked genes, resulting in the onset of genetic diseases and/or the absence of the DNA probe detectable sequences. This permits the localization of these loci within the deleted area. On the other hand, the region for some other X-linked loci can be excluded from the deleted area according to the absence of the characteristic symptoms of the disease and/or the presence of the hybridization signals. An interstitial deletion on the long arm of the X chromosome of a male has been characterized by high resolution banding. The karyotype of the proband is 46,Y,del(X)(pter----q21.1::q21.33----qter). The regions for 12 X-linked disease loci as well as 10 DNA probes are excluded from the deleted area, and localized either proximally or distally to the deletion. The results also reveal a controversy in the present linkage data concerning the assignment of these loci.

Abnormalities, Multiple↗
PubMed1986

Choroideremia: further evidence for assignment of the locus to Xq13-Xq21.

Choroideremia is an X-linked hereditary retinal dystrophy leading to blindness in early adulthood. RFLP analyses in three Danish families were consistent with close linkage between choroideremia and the locus DXYS1, located at Xq13-Xq21. Measurable linkage was found between choroideremia and DXS17, at Xq22. Furthermore, choroideremia was diagnosed in a boy with an interstitial deletion at Xq13-Xq21, strongly suggesting the assignment of the locus for choroideremia to this region of the X chromosome. The deletion also covered DXYS1, but did not include DXS17.

Chromosome Mapping↗
PubMed1986

The frequency of false-positive and false-negative results in the detection of Y-chromosomes in interphase nuclei.

In blood smears from 527 females and 457 males examined for the presence of Y chromosomes in interphase nuclei, 0.6% false-positive results and 11% false-negative results were found. There was a clear tendency for the false-negative results to occur among those with small fluorescent or non-existing bands on the Y chromosome. The three false-positive females all had fluorescent chromosomal variants. In a comparison between female samples with and without chromosomal variants respectively, the former showed significantly higher false Y-body counts. There was a decrease in the number of Y-bodies with increasing age. There were no significant differences between staining with 0.1% Quinacrine mustard and 0.1% and 1% Mepacrine. This study provides a more solid basis for the use of Y chromosome detection in forensic medicine, for screening purposes etc.

Adolescent↗
PubMed1986

Linkage between the loci for cystic fibrosis and paraoxonase.

In a material of 22 Danish, 26 Canadian, 10 Australian, 5 English and 5 American families with at least 2 children affected with cystic fibrosis (CF) a combined positive LOD score of 3.46 was found for the relationship cystic fibrosis-paraoxonase (PON) at recombination fraction theta = 0.07 in males and theta = 0.13 in females. Assuming a three allele model for PON the LOD score was 4.50 at the same recombination fractions. This confirms our earlier finding of an indication of CF-PON synteny.

Alleles↗
PubMed1986

Choroideremia in interstitial deletion of the X chromosome.

An earlier reported family with a deletion of the proximal long arm of the X chromosome was reinvestigated with special attention to the presence of choroideremia. Two females were identified as carriers of choroideremia while a tapeto-retinal dystrophy was ascertained in a mentally retarded boy. RFLP analysis revealed that the interstitial deletion covered the locus DXYS1 and not DXS17. Chromosome studies indicated a deletion within the Xq21 area.

Abnormalities, Multiple↗
PubMed1979

Anthropometry in the Cri du Chat syndrome.

Anthropometric and cranial X-ray measurements of 35 individuals with a 5p- karyotype showed a general growth retardation. Height, weight, circumference of the thorax, pelvic breadth, and the size of the skull, face, hands and feet were all subnormal. Only the inner canthal distance was moderately increased, especially in young individuals, but there was no true hypertelorism. The palate was not high-arched. Large and small terminal deletions produced much the same anthropometric features; and the proband's sex did not have a major influence. Age variations within parameters examined followed the developmental pattern of normal individuals. A certain phenotypical variation in the Cri du Chat syndrome may therefore be attributed to normal changes or to intrapersonal conditions.

Adolescent↗
PubMed1978

The Cri du Chat syndrome: epidemiology, cytogenetics, and clinical features.

Data for 331 cri du chat cases, including 34 Danish probands, are reviewed. The incidence nad the prevalence among the mentally retarded population amounted to 1/45,000 and 1.5/1000, respectively. No striking association with prenatal events, parental ages, or birth order could be demonstrated. There was a significant excess of females. Parental translocations were present in slightly more than 10% of the families, while more rare cytogenetic aberrations (mosaicism, rings, and de novo translocations) accounted for less than 10% of all cases. The phenotypically relevant segment has been narrowed down to the midportion of the 5p15 band. Clinical, radiologic, and dermatoglyphic features are summarized and discussed, with special attention to the abnormal cry, which persists in many older probands, and to developmental abnormalities. No obvious correlation could be detected between clinical features and the localization of the deletion. No marker locus has yet been assigned to the short arm of chromosome 5. Treatment and prevention are briefly discussed.

Adolescent↗
PubMed1978

Cytologic observations in 35 individuals with a 5p- karyotype.

Chromosome investigation of 35 individuals with a 5p- karyotype and their families revealed the presence of 27 apparently terminal deletions, four interstitial deletions, and four translocations, including two familial cases. Four of the probands with simple deletions and one of the mother were mosaics. Unusual chromosomal heteromorphism, as rendered visible after acridine orange staining, was observed on the short arm of chromosome 14 in two cases and, after heterochromatin staining, on chromosome 19 in one family. Measurement studies, carried out in probands with simple deletions and in two control groups, showed a short-arm loss clustering between 32% and 62% of the normal short-arm length. Using at least two complementary staining methods per proband, we found that the midportion of the 5p15 segment probably must be deleted to develop the typical clinical features of the cri du chat syndrome.

Acridines↗
PubMed1978

Measurements on hand radiographs from 32 cri-du-chat probands.

Various measurements were performed on the hand radiographs of 32 Danish cri-du-chat probands. Mean pattern profiles were made for males, females, children, and adults. Metacarpal index and relative slenderness for metacarpals and proximal phalanges were calculated. The hands were smaller than in normal persons of the same sex and age. In most of the probands, the 3rd, 4th, and 5th metacarpals were disproportionately short, and the 2nd, 3rd, 4th, and 5th proximal phalanges were disproportionately long. Only 1 case had a positive metacarpal sign.

Adolescent↗
PubMed1978

Serologic markers and chromosome variants in a pair of chimeric twins.

A pair of chimeric twins, T.S. (male) and M.R. (female) first examined in 1970 are reinvestigated in order to determine if the proportions of admixture of red cells in their blood are unchanged, and if erythrocytes and leukocytes show the same percentage of admixture. T.S., M.R. and their family are investigated for HLA, serum types, and erythrocyte antigens and enzymes. A quantitative determination of 'foreign' cell populations in the blood of each twin is attempted for the systems ABO, and HLA, and for sex chromosomes in PHA stimulated lymphocytes. The results for the ABO system obtained by agglutination technique and by a double-layer immunofluorescence technique indicate that the population of M.R. erythrocytes in T.S. has decreased during the 7-year period, and is now below half the size found in 1970. Erythrocytes and leukocytes show the same percentage of admixture in both twins.

ABO Blood-Group System↗