Bilateral congenital diaphragmatic hernia: Differentiation between Pallister‐Killian and Fryns syndromes

Many types of chromosome mosaicism have been identified in cases of hypomelanosis of Ito, often in association with chromosome instability; however, there have been very few cases with diploid–tetraploid mosaicism described in the literature. We present a patient with a tetraploid mosaicism: a 17‐year‐old girl who has hypomelanosis of Ito in association with diploid/tetraploid/t(1;6) mosaicism. She had multiple congenital anomalies of omphalocele, exstrophy of bladder, duodenal web, and imperforate anus. These features have not been described previously in diploid–tetraploid mosaicism. © 2002 Wiley‐Liss, Inc.     

Diploid/tetraploid/t(1;6) mosaicism in a 17-year-old female with hypomelanosis of Ito,multiple congenital anomalies,and body asymmetry

Many types of chromosome mosaicism have been identified in cases of hypomelanosis of Ito, often in association with chromosome instability; however, there have been very few cases with diploid-tetraploid mosaicism described in the literature. We present a patient with a tetraploid mosaicism: a 17-year-old girl who has hypomelanosis of Ito in association with diploid/tetraploid/t(1;6) mosaicism. She had multiple congenital anomalies of omphalocele, exstrophy of bladder, duodenal web, and imperforate anus. These features have not been described previously in diploid-tetraploid mosaicism.     

Interphase-FISH study in three patients with tetraploid/diploid mosaicism

We report tetraploid/diploid mosaicism in a boy and two girls detected by cultured skin fibroblasts. In all these children, interphase-FISH using DXZ1 probe confirmed the original karyotype. Tetraploid mosaicism was also confirmed by alpha-satellite probes from chromosomes 2, 6, 7, 9, 10, 17, 18 and Y in fibroblasts from the boy. The common features in these children are failure to thrive, slight mental deficiency and some degree of body asymmetry. The advantage of using interphase-FISH is the possibility of analysing a great number of cells in short time, thus giving a more precise percentage with regard to abnormal cells.     

Diploid/Tetraploid Mosaicism in the Offspring of a 46XX/47XXX Mosaic Mother

A 10½-year-old boy with an IQ of 71, short stature, and isolated growth hormone deficiency was found to have diploid/tetraploid mosaicism. He was born to a 46xx/47xxx mosaic mother. The mother was found to be moderately mentally retarded but showed no other abnormalities. A review of literature pertinent to this case is presented.     

Establishment of proliferative tetraploid cells from telomerase‐immortalized normal human fibroblasts

Aneuploidy is observed in the majority of human cancers and is considered to be causally related to carcinogenesis. Although malignant aneuploid cells are suggested to develop from polyploid cells formed in precancerous lesions, the mechanisms of this process remain elusive. This is partly because no experimental model is available where nontransformed polyploid human cells propagate in vitro. We previously showed that proliferative tetraploid cells can be established from normal human fibroblasts by treatment with the spindle poison demecolcine (DC). However, the limited lifespan of these cells hampered detailed analysis of a link between chromosomal instability and the oncogenic transformation of polyploid cells. Here, we report the establishment of proliferative tetraploid cells from the telomerase‐immortalized normal human fibroblast cell line TIG‐1. Treatment of immortalized diploid cells with DC for 4 days resulted in proliferation of cells with tetraploid DNA content and near‐tetraploid/tetraploid chromosome counts. Established tetraploid cells had functional TP53 despite growing at almost the same rate as diploid cells. The frequency of clonal and sporadic chromosome aberrations in tetraploid cells was higher than in diploid cells and in one experiment, gradually increased with repeated subculture. This study suggests that tetraploid cells established from telomerase‐immortalized normal human fibroblasts can be a valuable model for studying chromosomal instability and the oncogenic potential of polyploid cells. © 2016 Wiley Periodicals, Inc.     

Cytogenetic and dermatoglyphic findings in a familial case of hypomelanosis of Ito (incontinentia pigmenti achromians)

Cytogenetic and dermatoglyphic investigations were performed in a mother (M.B.) and her daughter (D.B.), who were both suffering from hypomelanosis of Ito (incontinentia pigmenti achromians; HI). Whereas quite normal chromosomal results could be obtained after culture of peripheral lymphocytes, a diploid/tetraploid mosaicism (46,XX/92,XXXX) was found in cultured skin-fibroblasts derived from a hypopigmented skin area of M.B., with a slowly decreasing tetraploidy rate in the course of passaging: #2 23%, #5 11%, #11 and #14 6% and #18 and #21 2%. In cultures of normally pigmented skin, only single tetraploid cells could be detected. Dermatoglyphic examinations in both patients showed single transverse creases, a high number of secondary creases and a longitudinal alignment of the main line A bilaterally, and there was a tricentric fingertip pattern on the right digit III of M.B., i.e. a pattern which occurs very seldom in human beings. The results are discussed in respect to the clinical-diagnostic overlap of HI and incontinentia pigmenti Bloch-Sulzberger.     

The changing phenotype in diploid/triploid mosaicism may mimic genetic syndromes with aberrant genomic imprinting: follow up in a 14-year-old girl

Diploid/triploid mosaicism is a rare chromosome aberration characterized by growth and mental retardation, muscular hypotonia, clinodactyly, syndactyly of fingers and toes, asymmetry of the body and the face, truncal obesity, and pigmentary anomalies of the skin. Many patients initially present with severe growth retardation and develop truncal obesity later in life. Variable phenotype expression during development and restriction of triploid cells to certain tissues explain why the diagnosis of diploid/triploid mosaicism is often delayed. Here, we report on a moderately retarded 14-year-old girl with diploid/triploid mosaicism due to inclusion of the second polar body, whose changing phenotype overlaps considerably with different genetic disorders associated with aberrant genomic imprinting. The observation that triploid cells, which in our patient show remarkably variable distribution in different tissues, may also be present in easily accessible tissues such as urinary sediment or buccal smear may contribute to an earlier diagnosis of this rare syndrome.     

Monozygotic twin girls with diploid/triploid chromosome mosaicism and cutaneous pigmentary dysplasia

Diploid/triploid mosaicism is an uncommon clinical syndrome with a subtle but distinctive phenotype. Characteristic features include prenatal and postnatal asymmetric growth deficiency, triangular and/or asymmetric facies, micrognathia, finger and/or toe syndactyly, clinodactyly, single transverse palmar creases, male genital anomalies, hypotonia and psychomotor retardation. This disorder is underdiagnosed because in 70% of cases the triploid cell line is only seen in fibroblasts. In cases in which a triploid cell line is found in lymphocytes, it usually occurs in less than 5% of cells. While some reports of diploid/triploid mosaicism have mentioned unusual skin pigmentary patterns, including hypomelanosis of Ito, it was only recently recognized that this is a helpful diagnostic clue in mosaic chromosome disorders. We report monozygotic twin girls with diploid/triploid mosaicism whose cutaneous pigmentary dysplasia led to their diagnosis.     

Mosaicism in the inner cell mass of human blastocysts

Although mosaicism was shown to be a normal feature in cleaving embryos, its consequences for the late preimplantation stages are unknown. We performed blastocyst immunosurgery, followed by fluorescent in-situ hybridization (FISH), to determine the number of cells and degree of mosaicism in the inner cell mass (ICM) of human blastocysts. Of 47 ICM samples analysed, 20 had aneuploid cells, and two also had a few tetraploid cells. The average degree of aneuploidy in the ICM was similar to the overall blastocyst mosaicism, suggesting that there is probably no selection for euploid ICM. The lower degree of blastocyst mosaicism, compared with the cleavage-stage embryos, may be due to a mechanism of selection against the embryos with high frequency of mosaicism, leading to elimination of these embryos prior to blastocyst formation.      

Feulgen-DNA-values in transitional cell carcinoma of the human urinary bladder.

Feulgen-stained imprint smears from 24 biopsy specimens from transitional cell carcinoma of the human urinary bladder were examined by means of scanning cytophotometry. One hundred randomly selected nuclei were measured from each biopsy specimen and the results compared with analogous measurements of nuclei from normal urinary transitional cell epithelium (13 cases in the control group). 97% of the nuclei in the control group were diploid. Well differentiated transitional cell carcinoma of the bladder mainly had a diploid DNA-stemline comprising 85% or more of the cells. One case of a well differentiated bladder cancer with a tetraploid DNA-stemline was found. The different cases of moderately differentiated bladder cancer showed diploid, triploid, tetraploid and hexaploid DNA-stemlines, while 4 out of 5 poorly differentiated tumours had a diploid DNA-stemline. The fifth extremely de-differentiated bladder carcinoma did not have any DNA-stemline at all. Together with these changes of the ploidy of the DNA-stemlines, increasing undifferentiation of the tumour tissue was combined with a reduced number of cells belonging to the tumour DNA-stemline, and increasingly scattered distribution of cells not contributing to the DNA-stemline. This indicates increased proliferative activity and/or chromosomal instability of the poorly differentiated cell population. Predominance of cells in the diploid, tetraploid and or octoploid intervals without marked frequency of DNA-values in the intermediary classes seemed to be a sign of clinical more "benign" bladder tumours, while a clinically more "malignant" tumour is characterized by increase of DNA-values in the triploid and hexaploid classes.     

Changes in pancreatic acinar cell nuclear number and DNA content during aging in the rat

Pancreatic acinar cells from rats 5 to 658 days (94 weeks) of age were isolated by enzymatic dissociation and stained with the DNA specific fluorochrome Hoechst 33258. The nuclear DNA content and the incidence of binucleation were estimated in these cells. Total pancreatic weight, RNA, protein and DNA, and the incorporation of ³H-thymidine into pancreatic acinar cell DNA were also estimated in similar animals as measures of pancreatic growth. From 5 to 17 days after birth, 95% of the cells were mononucleate diploid and 5% were binucleate diploid; but during the period of rapid pancreatic growth over the following 39 days, acinar cells became increasingly binucleate. By 56 days after birth, 64% of cells were binucleate with a diploid DNA content per nucleus; and the incidence of binucleation then remained constant. At 28 days of age, 4% of mononucleate cells were tetraploid, increasing to 6% at 658 days of age. At this time 3% of binucleate cells contained dual tetraploid nuclei. There is thus a rapid development towards diploid binucleate acinar cells in the growing, postnatal pancreas; and in the adult pancreas a small proportion of these cells develop tetraploid nuclei.     

Chromosomal mosaicism throughout human preimplantation development in vitro: incidence, type, and relevance to embryo outcome

BACKGROUND: A large percentage of in-vitro generated cleavage stage human embryos are chromosomally mosaic, consisting of both normal (diploid) and abnormal (non-diploid) cells. The present study characterized mosaicism at each stage of cleavage division and examined its effect on preimplantation development in vitro. METHODS: A total of 216 normally fertilized (two-pronucleate) embryos which were not selected for transfer to the patients were analysed for chromosomal abnormalities using multi-colour fluorescence in-situ hybridization DNA probes specific for three to five of nine different chromosomes (X, Y, 2, 7, 13, 16, 18, 21, 22). RESULTS: Overall, 48.1% of embryos were mosaic. The frequency of mosaic embryos increased from 15.2 to 49.4 to 58.1%, from the 2-4-cell to 5-8-cell to morula stages respectively, and the types of non-diploid cells detected were mostly aneuploid or chaotic. The incidence of mosaicism at the blastocyst stage was 90.9%; however, most of the mosaicism comprised diploid and polyploid cells. Arrested mosaic embryos had a higher incidence of chaotic abnormalities, and higher proportions of abnormal cells compared with the non-arrested group. CONCLUSIONS: Post-zygotic errors leading to mosaicism may occur, and persist throughout preimplantation development in vitro. Our results suggest that mosaicism involving multiple chromosomal imbalances and/or imbalances affecting a high proportion of cells in an embryo appear to impair development to the blastocyst stage.     

Erythropoiesis in the Diploid and Tetraploid Odontophrynus americanus: An Evolutionary Approach in These Cryptic Species (Amphibia, Anura, Leptodactylidae)

Polyploidy is one of Nature’s strategies to create diversity among fauna and flora, resulting in new species. We have used light, scanning and transmission electron microscopy to perform morphometric analyses in maturing erythroid cells of the cryptic species diploid and tetraploid Odontophrynus americanus frogs. Normal blood of both specimens contained 97%–99% erythrocytes and 1%–3% reticulocytes, besides thrombocytes and leucocytes. Mature erythrocytes were flattened, ellipsoidal, nucleated, with cytoplasm rich in haemoglobin. Five days after being made anaemic, 15% and 33% of diploid and tetraploid red blood cells respectively, were in an immature stage, basically proerythroblasts. These cells were also seen at the 10th day, in addition to basophilic and polychromatophilic erythroblasts. By day 15 a higher number, 75% and 89% of reticulocytes in earlier maturation stage was found, respectively. At day 20 of recovery from anaemia, there were 63% and 85% of reticulocytes, respectively, most in an advanced stage of maturation. The number of immature cells then gradually decreased at days 30 and 50. Cytoplasmic inclusions similar to Heinz bodies were found in these cells associated with RNA or RNP. Morphometric analysis showed that the tetraploid erythroid cells synthesise 30% more ribosomes than the diploid erythroid cells. The density of ribosomes/μm² allowed these cells to be classified into seven classes: proerythroblasts, basophilic erythroblasts I and II, polychromatophilic erythroblasts I and II, reticulocytes and erythrocytes. Such morphometric strategy suggested that gene activity was more intense in the tetraploid maturing erythroid cells, despite the marked tendency of these tetraploid cells towards diploidisation of the genome expression.     

Tetraploidy and Y chromosome loss in acute mixed-lineage leukemia

An unusual case of acute leukemia with mixed phenotype was followed up from diagnosis to death for about 12 months. The first cytogenetic examination revealed about 80% of the bone marrow cells in the diploid and 20% in the tetraploid range. After two courses of induction therapy, complete remission was achieved within 2 months. At this time the tetraploid cells were reduced to 3%, but 50% of the mitoses showed a Y chromosome loss, while the other mitoses had a diploid karyotype. Early intensification therapy was given 6 weeks later with slow recovery of blood counts. After four months a sharp decrease of the number of Y-missing mitoses was observed, while the marrow remained in full remission. Two months later a relapse occurred and the patient died. At this time the -Y clone had dropped to 2% and the tetraploid clone was totally absent. We conclude from these findings that the diploid clone was the most malignant one, whereas the -Y cells were probably not directly involved in the leukemic process.     

Erythropoiesis in the Diploid and Tetraploid Odontophrynus americanus : An Evolutionary Approach in These Cryptic Species (Amphibia, Anura, Leptodactylidae)

Polyploidy is one of Nature’s strategies to create diversity among fauna and flora, resulting in new species. We have used light, scanning and transmission electron microscopy to perform morphometric analyses in maturing erythroid cells of the cryptic species diploid and tetraploid Odontophrynus americanus frogs. Normal blood of both specimens contained 97%–99% erythrocytes and 1%–3% reticulocytes, besides thrombocytes and leucocytes. Mature erythrocytes were flattened, ellipsoidal, nucleated, with cytoplasm rich in haemoglobin. Five days after being made anaemic, 15% and 33% of diploid and tetraploid red blood cells respectively, were in an immature stage, basically proerythroblasts. These cells were also seen at the 10th day, in addition to basophilic and polychromatophilic erythroblasts. By day 15 a higher number, 75% and 89% of reticulocytes in earlier maturation stage was found, respectively. At day 20 of recovery from anaemia, there were 63% and 85% of reticulocytes, respectively, most in an advanced stage of maturation. The number of immature cells then gradually decreased at days 30 and 50. Cytoplasmic inclusions similar to Heinz bodies were found in these cells associated with RNA or RNP. Morphometric analysis showed that the tetraploid erythroid cells synthesise 30% more ribosomes than the diploid erythroid cells. The density of ribosomes/μm² allowed these cells to be classified into seven classes: proerythroblasts, basophilic erythroblasts I and II, polychromatophilic erythroblasts I and II, reticulocytes and erythrocytes. Such morphometric strategy suggested that gene activity was more intense in the tetraploid maturing erythroid cells, despite the marked tendency of these tetraploid cells towards diploidisation of the genome expression.     

Trisomy 8 mosaicism: selective growth advantage of normal cells vs. growth disadvantage of trisomy 8 cells

A fetus with trisomy 8 mosaicism was identified prenatally due to an abnormal maternal serum triple screen. Tissue samples were taken at birth to determine the level of trisomy 8 mosaicism found within embryonic and extra-embryonic tissues, rates of cell division for the two cell lines, and the effect of mosaicism on the phenotype. The level of trisomy 8 cells in blood and fibroblasts was higher than in placental tissue. Cell cycle kinetics, by incorporation of bromodeoxyuridine for 48 hr, was not significantly different between the trisomy 8 and normal cells for blood or amnion. Fluorescent in situ hybridization (FISH) using centromeric probe for chromosome 8 showed significantly more trisomy 8 in interphase vs. metaphase in lymphoblasts, umbilical cord fibroblasts, and chorion. The loss of trisomy 8 cells is not due to anaphase lag, as determined by micronuclei analysis. The similarity of cell cycle kinetics between trisomy 8 cells and normal diploid cells suggests some trisomy 8 cells are exiting the cell cycle prematurely. This growth disadvantage of trisomy 8 cells results in the appearance of growth advantage for diploid cells.     

A human tetraploid pachytene spermatocyte as the possible origin of diploid sperm: a case report

Diploid spermatozoa represent 0.2-0.3% of all spermatozoa in the normal population and cause 8.3% of diandric triploids. Errors in meiosis I and II are the most common mechanisms by which diploid spermatozoa are produced. Endoreduplication before meiosis has been suggested as a possible origin for tetraploid meiocytes, which might, in turn, produce diploid sperm. Synaptonemal complex (SC) spreads of a fertile man were immunolabelled (SCP3, MLH1 and CENP) and hybridized with subtelomere-specific multiplex fluorescent in situ hybridization (stM-FISH) assay for SCs identification. The unexpected finding of a tetraploid pachytene cell and the identification of all of its SCs demonstrate that synapsis and crossover events can occur in human tetraploid cells. Moreover, it indicates that diploid sperm may also originate from mitotic errors (endoreduplication) occurring before meiosis.     

Novel presentation of central core disease with nemaline bodies (rods) in the setting of diploid/triploid mosaicism

Diploid/triploid mosaicism is an uncommon malformation syndrome thought to result from incorporation of the second polar body into a blastomere nucleus of the developing embryo. Clinical manifestations include mental and growth retardation, truncal obesity, body asymmetry, hypotonia, syndactyly, clino-/camptodactyly, malformed low-set ears, and small phallus. Although muscular atrophy has been documented in 35% of cases of diploid/triploid mosaicism, to our knowledge histologic evidence of myopathy has not been reported. We present a novel case of diploid/triploid mosaicism with evidence of central core disease and nemaline bodies (rods). The histologic and ultrastructural features are described. A review of the literature is provided, including discussion of the various theories regarding the co-expression of central cores and nemaline rods.     

Changes in cellular ploidy and autophagic responsiveness during rat liver carcinogenesis

Liver carcinogenesis was initiated in young rats by diethylnitrosamine/partial hepatectomy and promoted by dietary 2-acetylaminofluorene (for 4 weeks). Eight weeks after initiation, hepatocytes were isolated by means of collagenase perfusion and analyzed by means of flow cytometry. Whereas cells and cell nuclei from normal or hepatectomized livers were predominantly tetraploid, most of the hepatocytes/nuclei from carcinogen-treated rats were diploid. Neoplastic liver nodules and hepatocellular carcinomas also contained almost exclusively diploid nuclei, suggesting that diploidization may be an essential feature of liver carcinogenesis. Two-parametric analysis (simultaneous flow cytometric determination of DNA and protein content within the same cell) revealed that the diploid cells were only half as big as the tetraploid cells. They could therefore be separated from the latter by centrifugal elutriation. Normal, isolated hepatocytes responded to amino acid deprivation by increasing their rates of autophagic sequestration (measured with electroinjected (14C)sucrose as a probe) and endogenous protein degradation, the resulting protein loss eventually leading to cell death. Hepatocytes from carcinogen-treated rats were much less responsive to amino acid deprivation, preserved their protein better, and survived for longer periods of time in culture than did normal cells. The reduced autophagic responsiveness may conceivably give carcinogen-altered cells a survival advantage even in vivo, that could contribute to their outgrowth during carcinogenesis.     

Chromosome investigations in early life. II. Human preimplantation embryos

Cytogenetic analysis of 68 human embryos at the 2-to 8-cellstage was performed according to Tarkowski's technique. Sixteenper cent of diploid embryos showed abnormalities, essentiallydiploid/haploid or triploid/haploid mosaicism. Considering theaspect of the embryos, 11% of healthy looking and 19% of fragmentedembryos were chromosomally abnormal without, however, any statisticalsignificance in this small series. Only 46.7% of the tripronucleatefertilized eggs showed a triploid chromosome complement. In20% of the cases, however, diploid metaphases were found, andin the last 30% a triploid/diploid mosaicism. One per cent ofthe oocytes displayed a single pronucleus, and the resultingembryos contained haploid sets of chromosomes suggesting a parthogeneticactivation. The overall rate of chromosome abnormalities, including16/ of abnormal diploid eggs, 6/ of polyploid and 1/ of haploidembryos, thus reaches 23/ in this series.