Chromosome abnormalities in 150 couples with multiple spontaneous abortions

One hundred fifty consecutive couples with recurrent abortions with or without fetal deaths, malformations, or healthy infants were evaluated cytogenetically with a G-band method. Seven couples (4.7%) showed a chromosome aberration in one partner (5 translocations, 1 inversion, and 1 gonosomal mosaicism). Of the couples with a pure abortion history, 2.9% had a chromosomal abnormality. A high incidence of chromosomal rearrangements in the groups of couples with abortions plus fetal deaths or malformations was found. In contrast to other reports, a high incidence of cytogenetic abnormalities was also found in couples with abortions and healthy infants. Chromosome analysis is advocated as a primary tool in the evaluation of couples with repetitive fetal wastage.

Differential fluorescent staining of porcine heterochromatin by chromomycin A3/distamycin A/DAPI and D 287/170

R banding of porcine chromosomes by chromomycin A3 plus distamycin A and DAPI (DA-DAPI) revealed two distinct types of heterochromatin: The GC-rich centromeric heterochromatin of the biarmed autosomes (Nos. 1-12) and of the X chromosome exhibited bright chromomycin A3 fluorescence, while the heterochromatin of the acrocentric chromosomes (Nos. 13-18) stained brightly by DA-DAPI. The latter also fluoresced brightly when stained by D 287/170. In addition, significant fluorescent polymorphism was observed among both acrocentric and metacentric chromosomes.

[Polymorphisms of the human chromosome no. 15 (author's transl)]

The short arm of the human chromosome No. 15 is composed of various heterochromatic regions. By using silver staining, mithramycin, Da-DAPI and quinacrine mustard fluorescence staining at least 5 different regions may be differentiated. All these components show independent heteromorphisms allowing easy individual identification of a given chromosome No. 15. These features may be useful for studies on heredity including affiliation cases.

[Cytogenetic findings in habitual abortion. Chromosomal analysis in 123 couples (author's transl)]

From the 1st of April 1974 till the 30th of September 1979 a consecutive series of 123 couples with a history of recurrent abortion was studied cytogenetically with modern banding techniques. 8 chromosomal aberrations were detected (6.5%); 3 women were found to be balanced reciprocal translocation carriers; the karyotype of 3 women and one man showed a pericentric inversion, one women was found to be a mosaic for 46 XX/45 X0. It is concluded from the results of this report that cytogenetic evaluation is indicated in cases of habitual abortion. The expected rate of chromosomal aberrations is especially high in couples with a mixed history of abortions, intrauterine fetal deaths and malformations. In case a chromosomal aberration is detected the patients have to be counselled individually according to the type of anomaly.

Effects of counterstaining with DNA binding drugs on fluorescent banding patterns of human and mammalian chromosomes

Pairs of fluorescent A-T specific dyes and nonfluorescent agents with similar or complementary base pair binding specificity were used to analyse the extent to which banding patterns in human chromosomes obtained by fluorescent staining can be modified by counterstaining. By testing a variety of different combinations of drugs, essentially three types of alterations were observed. Enhanced contrast of specific heterochromatic regions was obtained with pentamidine, or netropsin, in conjunction with the fluorescent stains Hoechst 33258, DAPI or DIPI, the resulting banding patterns being similar to that reported for distamycin A plus DAPI (DA-DAPI banding [21]. Uniform quenching of Hoechst 33258, DAPI or DIPI fluorescence was induced by counterstaining with stilbamidine or berenil. The combination of echinomycin with DAPI resulted in an improved contrast of DAPI banding on chromosome arms and pale fluorescence on major autosomal C band regions. In addition, a subdivision of the heterochromatic part of the Y chromosome may be discerned by this latter technique.

[Amniocentesis for antenatal diagnosis. A report on an initial series of 180 cases (author's transl)]

The results are presented of amniocentesis for diagnostic genetic purposes in 180 patients. A diagnosis was obtainable in 170 cases (94%). Genetic abnormalities were detected in 11 cases; one patient miscarried 3 days after amniocentesis. Antenatal diagnosis of certain genetic disorders can be considered a routine method nowadays and should be offered to any woman at risk. It therefore seems necessary to supply the practitioners with the relevant information on this topic.

[Amniocentesis for antenatal diagnosis. A report on an initial series of 180 cases (author's transl)]

The results are presented of amniocentesis for diagnostic genetic purposes in 180 patients. A diagnosis was obtainable in 170 cases (94%). Genetic abnormalities were detected in 11 cases; one patient miscarried 3 days after amniocentesis. Antenatal diagnosis of certain genetic disorders can be considered a routine method nowadays and should be offered to any woman at risk. It therefore seems necessary to supply the practitioners with the relevant information on this topic.

Antenatal diagnosis of a de novo reciprocal translocation 46,XX,t(3;7)(q21;q11)

A de novo reciprocal translocation 46,XX,t(3;7)(q21;q11), detected at amniocentesis performed because of advanced maternal age, is presented. Both parents showed a normal karyotype. The girl was delivered and has shown no phenotypic abnormality in the first year after birth. Problems encountered with the prediction of the fetal outcome in balanced structural rearrangements are discussed.

Structure and variability of human chromosomes analyzed by recent techniques

Besides the AT-specific fluorochromes, GC-specific fluorescent antibiotics are now available for chromosomal analysis. Chromosomal bands represent large accumulation of DNA sequences with similar AT:GC ratio. These uniform differences from the mean AT:GC ratio in the bands can be explained only by at least partial repetition of short DNA sequences in these regions. By comparison of various staining techniques more information also on the constitutive heterochromatin in man becomes available. The human NOR region exhibits a complex organization when studied by various base-specific fluorochromes and silver staining. The DNA-specific fluorochromes are also useful tools in cytophotometric DNA measurements.

The nature of the Ag-staining of nucleolus organizer regions. Electron- and light-microscopic studies on human cells in interphase, mitosis, and meiosis

Electron micrographs reveal that the Ag-stainable substance is located on the outside of NOR's or around them but not in the chromosomes themselves. In association figures, the Ag-positive material lies between the acrocentric chromosomes. Light-microscopic studies show that the Ag stainability of the nucleolus in interphase is correlated with the function of the NOR, as seen from inactive and activated lymphocytes. Much more Ag-positive material is seen in prophase than in meta- and anaphase. It starts to increase again in late telophase. In male meiosis the NOR's remain Ag-positive until pachytene. First and second metaphase figures are negative. Experiments using RNase, TCA, and trypsin indicate that the Ag-stainable substance is an acidic protein. The precipitation of Ag granules in interphase nuclei seen in the electron microscope is greatest over the fibrillar component of the nucleolus. The most likely interpretation is that the Ag-stainable material is a component of ribonucleic protein accumulating around active NOR's. In mitosis some of this material remains at the NOR's. In first meiosis it is completely removed before diakinesis.

Frequency of Ag-stained nucleolus organizer regions in the acrocentric chromosomes of man

The Ag-stainability of the nucleolus organizer region (NOR) was studied in the acrocentric chromosomes identified by Q-banding of cultured lymphocytes in 51 karyotypically normal persons (31 males and 20 females). A consistent pattern of Ag-positive NORs was found in each individual. Ninety percent of individuals have a model number of 8--10 Ag-positive NORs per cell. The frequency of Ag-positive NORs is similar in all five acrocentrics. A statistically nonsignificant lower frequency is found in chromosome 22. Ag-negative NORs on both homologues were found in four cases. The observed frequency distribution of individuals with homozygous NOR-positive, heterozygous, and homozygous negative acrocentric chromosomes was in accordance with the Hardy-Weinberg law in all five pairs of the acrocentric chromosomes as well as in total. No sex difference was observed on our material.

Mithramycin and DIPI: a pair of fluorochromes specific for GC-and AT-rich DNA respectively

The AT specificity of the fluorochromes DIPI and DAPI and the GC specificity of mithramycin are evidenced by observations in human, mouse, and bovine chromosomes. DIPI and DAPI produce a pattern similar to Hoechst 33258 in all three species, whereas mithramycin results in a reverse pattern. The AT-rich centromeric heterochromatin in mouse is brilliantly stained by DIPI or DAPI and remains nearly invisible after mithramycin staining. In the GC-rich centromeric heterochromatin of cattle the opposite behavior is observed.

DIPI and DAPI: fluorescence banding with only negliglible fading

DIPI and DAPI produce distinct fluorescent bands in human chromosomes similar to quinacrine banding patterns. Additionally, the AT rich secondary constrictions in the chromosomes Nos. 1, 9 and 16 are brightly fluorescent. On the other hand the brilliantly fluorescent regions after staining with quinacrine mustard in the chromosomes Nos. 3 and 4, satellites and some other regions in the acrocentric chromosomes are less striking. The distal part of the Y, however, is clearly discernible. Thus DIPI and DAPI seem to be strictly AT specific fluorochromes like Hoechst 33258. In interphase nuclei the Y chromosome can be identified. However, quinacrines are superior for Y-body analysis in buccal, hair cell and sperm smears. BrdU labeled chromatids show reduced fluorescence intensity. The difference, however, is less apparent than after staining with Hoechst 33 258. DAPI and especially DIPI are highly resistant to UV-irradiation; there is almost no fading within 30 min when using DIPI. Moreover, fluorescence intensity is stronger than in quinicrines. When photographing, exposure times may be reduced to about one quarter compared to quinacrine mustard.

[Catamneses of YY carriers in prison]

Among the 700 inmates of a big Austrian prison 5 cases of XYY caryotype were detected by means of the Quinacrinfluorescence method and subsequent lymphocyte culture. Keeping in mind that, if at all, only a small amount of criminal behavior may be explained by chromosomal factors three hypotheses about possible links between the XYY abnormality and criminal behavior are discussed in this paper. 1. the connection is a spurious one, as both criminal behavior and the XYY caryotype are more frequent in a working class population without being necessarily linked causally. 2. criminal behavior may be a consequence of the bodily abnormalities connected with the XYY abnormality. 3. the XYY type may contribute to criminal behaviour by acting upon neuro-endocrinological structures.

A photometric method for quantifying the polymorphisms in human acrocentric chromosomes

Photometric measurements on photomicrographs of quinacrine mustard--stained metaphase chromosomes, processed by a reverse developing procedure provide quantitative data on the polymorphisms of human acrocentric chromosomes. The method described is intended for population studies. The method is easily reproducible, allowing comparisons of data obtained by different laboratories.

[Translocation (13; 18) (q22; p 11) and prenatal diagnosis (author's transl)]

A balanced translocation (13; 18) (q 22; p 11) was diagnosed in two generations. Out of 10 pregnancies in these two translocation carriers, mother and daughter, only two phenotypically normal childern were born. One of these, namely the daughter, showed balanced translocation, whilst a normal karyotype was diagnosed prenatally in the second case. The other eight pregnancies ended either in spontaneous abortions, in intrauterine death or in lethal malformations. In the present translocation the formation of unbalanced gametes seems to be enhanced.

8-methoxypsoralen and UVA promote sister-chromatid exchanges

8-Methoxypsoralen (8-MOP) and long-wave UV light (UVA 365 nm) are now being use to treat vitiligo and psoriasis. Cultured human lymphocytes exposed to these agents in vitro show an increased infrequency of sister chromatid exchanges, related to 8-MOP-DNA photoadducts. Although these data raise questions regarding the biologic consequences of this therapeutic regimen, it is unknown whether 8-MOP and UVA cause mutations or extracutaneous somatic cell recombinants in vivo. Exchanges may represent cellular repair of DNA damage.

Increased sister chromatid exchange events in the human late replicating X

Human female blood cultures were labeled with BrdU for detecting sister chromatid exchanges (SCEs) by the Hoechst 33258 fluorescence technique. Late labeling with 3H-thymidine and autoradiography allowed the identification of the late replicating X. The mean number of SCEs in the cells was 13. The isopycnotic X showed an exchange frequency according to its relative length in the karyotype; in the late replicating X a doubled number of SCE events was observed.

Origin of the extra chromosome no. 21 in Down's syndrome

Eighteen of 38 examined families with children with Down's syndrome showed polymorphisms of chromosome 21 elucidating the origin of the extra chromosome 21. Maternal origin was found in 10 cases and paternal origin in 8 cases. In both sexes errors occurred both in the first and in the second meiotic division.

5-methylcytosine in heterochromatic regions of chromosomes in Bovidae

The centromeric regions of cattle, goat and sheep chromosomes bind anti-5-MeC as revealed by immunofluorescence technique, indicating concentration of 5-MeC at these heterochromatic regions. The centromere of the submetacentric X of cattle remains nearly unstained and so do the centromeres of the acrocentric X chromosomes in goat and sheep. The short arm of the cattle Y exhibits strong anti-5-MeC binding whereas the tiny Y chromosomes of goat and sheep contain no brightly fluorescent material.

[New methods in cytogenetic diagnosis (author's transl)]

Several different methods for identifying human chromosomes were developed over the past years. These methods include fluorescence techniques using quinacrine mustard, acridine orange or Hoechst 33 258 and special methods using Giemsa staining. Studies on replication of chromosomes were greatly improved by using BUdR labelling.