Translocation (4;11) in a case of malignant lymphoma.

The translocation t(4;11)(q21;q23) is considered a chromosomal marker of acute lymphoid leukemia. We report here a case of a well-differentiated B-cell type non-Hodgkin's lymphoma presenting the same (4;11) translocation.

[Role of karyotype in studying male infertility]. / Place du caryotype dans l'exploration de l'infertilité masculine.

The karyotype of 443 infertile males has been studied (infertility of unknown etiology). The sample has been divided in 3 groups according to the data of their spermogram: Gr 1--101 males with a normal spermogramm (selected through the sterility of their couple). Gr 2--185 infertile males with oligospermy (less than 20 millions spermatozoal/ml). Gr 3--157 infertile males with azoospermia. This study shows: --No significant difference in chromosomal aberration rate between group 1 and general male population. --A rate of 5% chromosomal aberration in group 2 (versus 0.7% in normal male population p less than or equal to 10(-8], nearly exclusively balanced translocations. --A rate of 21% chromosomal aberration in group 3, nearly exclusively 47, XXY or 46, XX (p less than or equal to -9). The karyotype is unlikely to bring any information in infertile males with normal spermogram; on the contrary it is of valuable interest in infertile males with abnormal sperm.

Reciprocal translocations: a way to predict the mode of imbalanced segregation by pachytene-diagram drawing.

The study of 151 reciprocal translocations associated with abnormal probands shows that the mode of imbalance at birth is determined by the nature of the involved chromosomes and by the position of the breakpoints. For each of the three modes (adjacent-1, adjacent-2, and 3:1) there is a corresponding pachytene diagram, so that for each translocation variety it is possible to predict the most probable mode of imbalance. The determining factor is the relative length of the different branches of the cross formed by the tetravalent. However, some heterochromatic regions (9qh, short arms of acrocentric chromosomes) and possibly R-negative regions have a minor role. The factors involved in these mechanisms seem to be the selection and the chiasma position; their respective roles are discussed.

Chromosome analysis of spermatozoa from a male heterozygous for a 13;14 Robertsonian translocation.

Cytogenetic analysis of 78 spermatozoa from a man heterozygous for a t(13;14) Robertsonian translocation was performed. R banding was applied for chromosomal identification. Incidence of normal and balanced complements were respectively 50% and 41.3%. Six unbalanced complements (7.7%) were observed, resulting from adjacent segregation. Although alternate segregation is the most common mode of distribution, the possibility of producing unbalanced zygotes exists. The frequency of abnormalities unrelated to the translocation was 16.5% including 12.8% hypohaploïdy, 2.5% hyperhaploidy, and 1.2% of structural aberrations. An excess of t(13;14) X complements was observed (24 with X versus 14 with Y). This may result from the close association between trivalent (13;14) and X chromosome observed in the pachytene spermatocyte nucleus.

Direct segregation analysis of reciprocal translocations: a study of 283 sperm karyotypes from four carriers.

Using the technique of in vitro human-hamster fertilization, sperm of four men heterozygous for 4 reciprocal translocations--t(4;17),t(5;13),t(6;7), and t(9;18)--was studied. Frequencies of numerical abnormalities unrelated to the translocations range from 8.3% to 13.3%, and the incidence of imbalances ranges from 23.0% to 66.0%. Results are pooled with data from the nine other reciprocal translocations reported elsewhere, and the combined data demonstrate that male meiotic segregation is not random: whatever the type of translocation may be, the distribution of imbalances in sperm is constant, with approximately 72.0% adjacent 1, 18.5% adjacent 2, and 9.5% 3:1 segregations. The same prevalence of adjacent 1 segregations as that reported at term for translocations of paternal origin is observed. There is a strong postzygotic elimination process; for a given translocation it affects selectively the maximum-imbalance zygotes so that imbalanced segregations observed at term are always predetermined.

[Cytogenetic analysis of the Bloom syndrome. A study of the exchange-break relationship]. / Analyse cytogénétique du syndrome de Bloom. Etude de la relation échange-cassure.

Cytogenetic study of a case of Bloom's syndrome (number 46 of the international registry) confirms the excess of exchanges in all cellular types with the exception of a minority of lymphocytes and of two lymphoblastoid cell lines. These exchanges are produced in an X or U fashion between sister chromatids or between homologous chromatids and produce both simple and complex figures for which symmetry is the common feature. Some of these structures are rearranged secondarily, producing centric or acentric fragments and marker chromosomes. Triradial configurations are considered to be the result of exchanges rather than of partial endoreduplication. Chromatid and chromosome breaks are interpreted to result from incomplete exchanges. It is suggested that the general propensity for exchanges is the primary event responsible directly or indirectly for the cytogenetic observations rather than a defect in one of the DNA-repair mechanisms. No increase in mitomycin C sensitivity appears in vitro. The excess of SCEs is partially correlated by contact in vitro with normal cells and to a lesser degree by the culture medium in which the cells were grown.

Partial trisomy for the long arms of chromosome no. 5 due to insertion and further 'aneusomie de recombinaison'.

Five members of a family with a balanced insertion (1;5)(q32;q11q22) are presented. The daughter of one of them shows multiple malformations and a partial trisomy for the long arms of chromosome No. 5 (5q11 to 5q22 segment) resulting from a 'aneusomie de recombinaison' in her mother. The propositus' karyotype is 46,XX,rec(1;5)ins (1;5)(q32;q11q22). This case is the first reported example of an insertion between two chromosomes followed by 'aneusomie de recombinaison'. It also is the first reported case of trisomy invovling the long arms of chromosome No. 5.

Achievement of meiosis in XXY germ cells: study of 543 sperm karyotypes from an XY/XXY mosaic patient.

Human sperm chromosomes from a 46,XY/47,XXY male were obtained using the technique of in vitro penetration of zona-free hamster eggs. The analysis of 543 sperm complements shows a significantly increased incidence (0.9%) of hyperhaploid gonosomal 24,XY sets, with a lack of the expected corresponding gonosomal hypohaploidies, and a normal rate of autosomal non-disjunctions. These results support the suggestion that 47,XXY cells are able to go through meiosis and to form spermatozoa. Only 24,XY sperm chromosomal constitutions were observed suggesting a preferential pairing of homologous sex chromosomes in 47,XXY spermatocytes.

[Ring chromosome 14 in monozygotic twins]. / Chromosome 14 en anneau chez des jumelles monozygotes.

An r(14) is observed in monozygotic twins, with psychomotor retardation and no obvious somatic malformation.

[Ring-20 chromosome: a new syndrome]. / Chromosome 20 en anneau: un nouveau syndrome.

A comparative study of five observations of a r (20) syndrome characterized by facial dysmorphism, the absence of severe malformations, and rather late onset of encephalopathy and seizures.

[Mechanism of duplication formation relating to a case of 10q22 to q25 duplication]. / Mécanismes de formation des duplications a propos d'une observation de duplication 10q22àq25.

A duplication 10q22q25 was studied in the fetus of a mother carrier of a t(14q21q). On this occasion, duplications reported in the literature are reviewed. Chromosomal rearrangements involving two breaks always result in tandem duplications, while three break- rearrangements result in tandem or mirror adjacent duplications, or in non adjacent direct or inverted duplications, or in direct or inverted autointerstitial duplications.

[Reciprocal translocation at the origin of a Robertsonian translocation 15;22 by the loss of a metacentric chromosome. Genetic counseling]. / Translocation réciproque à l'origine d'une translocation Robertsonienne 15;22 par perte d'un chromosome métacentrique. Conseil génétique.

One of the children of a t(15;22) (q111;p11) woman has lost the minute metacentric der(15) without any clinical consequence, indicating the inocuity of the 15pter----q111 and 22pter----p11 monosomies. The segregation mechanism of this monosomy and, from this family, the relation between reciprocal translocations and Robertsonian translocations are discussed. Another subject with r(22) in the same family questions on an hypothetic common origin.

[Demonstration of human spermatozoa chromosomes in a heterospecific system: technical difficulties]. / Mise en évidence des chromosomes de spermatozoïdes humains dans un système hétérospécifique: difficultés techniques.

The incidence of chromosomal abnormalities at conception has been estimated to be very high about 40%; these estimations have been made on indirect evidence provided by karyotyping spontaneous abortions products. Now direct evidence is available, consisting in sperm chromosome analysis by using fertilization of zona-free eggs of the golden hamster. In our experience 175 assays have been performed with modifications of the technique described by Martin et al. (1982) and by Brandriff et al. (1984). Consistent results are obtained since the last 30 assays, using for the first time an R banding technique. Chromosomal analysis of 48 spermatozoa from 7 normal males is reported. The frequency of abnormal sperm complements (21%) is higher than reported by previous reports.

[Cytogenetic aspects of diffuse scleroderma : structural anomalies and sister chromatid exchanges (author's transl)]. / De la sclérodermie généralisée aspects cytogénétiques: anomalies structurales et échanges de chromatides-soeurs.

Structural chromosome anomalies (1 477 cells examined) and sister chromatid exchanges after two replication cycles with BrdU (771 cells studied) were evaluated in 12 patients with diffuse scleroderma and having received no recent or important irradiation. The increase of structural anomalies, chromatidic as well as chromosomal, is always low, inconstant and cannot be considered as having a diagnostic value. Increase of sister chromatid exchanges could be a more sensitive method of investigation. In particular, it is not influenced by low doses of diagnostic X-rays.

[Cytogenetic aspects of diffuse scleroderma. Structural anomalies and sister chromatid exchanges]. / Aspects cytogénétiques de la sclérodermie généralisée. Anomalies structurales et échanges de chromatides-soeurs.

Structural chromosome anomalies (1 477 cells examined) and sister chromatid exchanges after two replication cycles with BrdU (771 cells studied) were evaluated in 12 patients with diffuse scleroderma and having received no recent or important irradiation. The increase of structural anomalies, chromatidic as well as chromosomal, is always low, inconstant and cannot be considered as having a diagnostic value. Increase of sister chromatid exchanges could be a more sensitive method of investigation. In particular, it is not influenced by low doses of diagnostic X-rays.

[Encephalopathy related to X fragility: neither inactivation nor deletion of the distal fragment q28 to qter. Enzymatic and morphometric evidence]. / L'éncéphalopathie liée à la fragilité de l'X: ni inactivation, ni délétion du fragment distal q28 leads to qter. Arguments enzymatiques et morphométriques.

Hypothesis on the nature of the fragile site Xq28 and its relations with the specific phenotype are discussed. The roles of a local inactivation (tested by G6-PD activity in 9 patients) or of a deletion Xq28 leads to qter (studied by morphometric evaluations on 2 patients and their heterozygotic mother) are not confirmed.