Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MOSAICISM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources
PubMed1993

Mosaicism in chorionic villus sampling: an analysis of incidence and chromosomes involved in 2612 consecutive cases.

The incidence of chromosome mosaicism was analysed in 2612 consecutive chorionic villus sampling (CVS) cases. True mosaicism was found in five cases (0.19 per cent). Confined placental mosaicism (CPM) occurred in 51 cases (1.9 per cent). The chromosomes most frequently encountered in CPM were 2, 7, 8, and the sex chromosomes. Three types of CPM as proposed by Kalousek et al. (1992) were observed. Cases with CPM had a statistically significant association with spontaneous abortion (chi 2 = 3.92, p < 0.05). Based on the data analysed, we conclude that (1) CPM is as likely to occur in cultured chorionic villi as in the direct preparation; (2) as with amniocyte culture, chromosome 2 mosaicism occurs commonly in villus culture; (3) the incidence of false-positive results can be greatly reduced and concern about maternal cell contamination can be alleviated by using both direct cytotrophoblast preparation and cultured chorionic stroma cells in all cases; and (4) follow-up cytogenetic and obstetrical studies, such as ultrasound and fetal monitoring, should always be considered in cases where CPM is suspected.

Cells, Cultured↗
PubMed1993

Follow-up of pregnancies complicated by placental mosaicism diagnosed by chorionic villus sampling.

Thirty-nine (2.3 per cent) of 1724 chromosome studies from diagnostic chorionic villus samplings (CVS) done between 1983 and 1990 showed either level III (true) mosaicism (1.2 per cent) or level II (pseudo-) mosaicism (1.1 per cent) for chromosomal aneuploidy. Follow-up information on these 39 pregnancies was collected from questionnaires to families, paediatricians, and obstetricians. For all cases in which the pregnancy was continued and further testing was accomplished, the mosaicism was felt to be confined to the placenta. As compared with a control group of pregnancies evaluated by CVS with normal karyotypes, there was no increased incidence of pregnancy loss, congenital malformations, or developmental delay in the infants. Although intrauterine growth retardation occurred in several of the level III mosaic cases, adequate catch-up growth has been demonstrated.

Abortion, Spontaneous↗
PubMed1994

True trisomy 15 mosaicism, detected by amniocentesis at 12 weeks of gestation and fetal echocardiography.

A case of mosaicism of trisomy 15, with two-thirds of the cells trisomic, was detected at 12 weeks of gestation in amniotic fluid cell cultures obtained with the filtration technique. Ultrasound examination at 13 weeks showed a nodule protruding into the amniotic cavity which was speculated to be remnants of a co-twin, causing the trisomic cell line. At 20 weeks of gestation, a malformation scan (level III) was normal, but supplementary fetal echocardiography revealed a severe cardiac defect (mitral atresia and a ventricular septal defect). Fetal lymphocytes obtained by cordocentesis showed trisomy 15 mosaicism, but only in 5 per cent of the mitoses. After termination, the same percentage of trisomy 15 mosaicism was found in cells from skin and tendon as in the original early amniocentesis. No sign of earlier twinning was found in the placenta or membranes. We conclude that mosaicism in early amniotic fluid obtained by the filter technique in this case reflected the true karyotype accurately and that supplementary echocardiography added significantly to the interpretation of the clinical implications.

Adult↗
PubMed1994

Postnatal confirmation of prenatally diagnosed trisomy 16 mosaicism in two phenotypically abnormal liveborns.

Two phenotypically abnormal liveborns in whom trisomy 16 mosaicism was diagnosed prenatally by amniocentesis are described. Analysis of a percutaneous umbilical blood sample in one case revealed a normal chromosomal complement. Ultrasound examinations performed at the time of amniocentesis were normal. Serial sonography during the late second and third trimesters demonstrated progressive intrauterine growth retardation (IUGR) in both fetuses and a cardiac defect in one. At birth, both infants had dysmorphic features and multiple congenital anomalies. Trisomy 16 mosaicism was confirmed postnatally in both infants in skin fibroblasts; however, peripheral blood samples contained only chromosomally normal cells. The two mosaic trisomy 16 cases described in this report, together with the five confirmed cases reported previously, demonstrate the need for caution in the counselling of patients when trisomy 16 mosaicism is diagnosed prenatally in amniotic fluid samples. Such cases potentially can result in the birth of dysmorphic infants with significant birth defects, growth retardation, and possible developmental disabilities.

Abnormalities, Multiple↗
PubMed2002

Prenatally detected trisomy 7 mosaicism in a dysmorphic child.

Trisomy 7 mosaicism was detected prenatally in cultured amniocytes but not in fetal lymphocytes. The child that was born had pigmentary changes of the skin and facial asymmetry suggestive of a chromosomal mosaicism. Skin fibroblasts were studied and trisomy 7 mosaicism was confirmed. At 3 years of age the boy had developed mentally within normal limits. However, dysmorphic findings include sparse hair, short left palpebral fissure, ptosis of the left eyelid, strabismus, enamel dysplasia, low-set and posteriorly rotated ears and undescended testes. These findings share some common features with previously reported cases of trisomy 7 mosaicism.

Adult↗
PubMed2003

Prenatally detected trisomy 4 and 6 mosaicism--cytogenetic results and clinical phenotype.

We report on a live-born male with 46,XY/47,XY+4/47,XY,+6 mosaicism. Trisomy 4 mosaicism was detected by karyotyping chorionic villus samples (CVS) and was confirmed by the analysis of 16 metaphases obtained from cultured amniotic fluid cells. Eight metaphases were normal (46,XY), two had trisomy 4 (47,XY,+4), and two had trisomy 6 (47,XY,+6). Two postnatal chromosomal analyses of blood lymphocytes at birth and at the age of one week were normal. Chromosomal analysis of cultured skin fibroblasts from the right inguinal region at the age of 12 months revealed trisomy 4 (47,XY,+4) in 49 metaphases, trisomy 6 (47,XY,+6) in 2 metaphases, and a normal karyotype (46,XY) in 49 cells of the 100 analyzed metaphases, respectively. The main clinical findings consist of prenatal growth retardation, hypoplasia of the right side of the face, a dysplastic and posteriorly rotated right ear, a high vaulted palate, retrognathia, aplasia of the right thumb, hypoplasia of the fingernails, a deep sacral dimple, and patchy skin hypopigmentation of the right leg. When last seen at the age of 14 months, his development was nearly normal. Five patients with trisomy 4 mosaicism have been reported previously, but none with an additional trisomy 6 mosaicism.

Abnormalities, Multiple↗
PubMed1993

Development of myelin mosaicism in the optic nerve of heterozygotes of the X-linked myelin-deficient (md) rat mutant.

The oligodendrocyte population of the optic nerve has been suggested to arise either from a radial migration of neuroepithelial cells of the optic stalk or from the longitudinal migration of progenitor cells into the optic nerve from the brain, via the optic chiasm. Female heterozygotes of the X-linked myelin deficient (md) rat trait show a marked mosaic pattern of myelination of the optic nerves. This degree of mosaicism is not observed in other parts of the central nervous system. A total of 235 optic nerves from female rats of from 3 weeks to 24 months of age were examined by light microscopy. Nerves (104), from rats of all ages, showed defects in myelination consisting of distinct patches of non-myelination, often sharply demarcated from adjacent areas of normally myelinated axons. In some animals the abnormality was grossly apparent as areas of transparency within the intact optic nerves. In the majority of optic nerves showing mosaicism, defects in myelination were observed along the whole length of the nerve. However, a worsening of the defect toward the retinal end of the nerve was noted in 15 optic nerves, and an additional 11 nerves showed a defect in this region alone. It was also found that a number of rats had mosaicism in only one optic nerve. The preferential involvement of the retinal end of the optic nerves, and the asymmetrical involvement of the optic nerves within individual rats, is interpreted as indirect evidence in support of the proposed longitudinal migration of the oligodendrocyte precursor into the optic nerve.

Animals↗
PubMed1994

A cell-autonomous, ubiquitous marker for the analysis of Drosophila genetic mosaics.

Mosaic analysis, the study of animals containing cells of two different genotypes, has been used to address a wealth of questions in developmental biology. Up to now, the cell markers used to distinguish cells of the two genotypes have only been applicable to specific experimental situations (e.g., only in adult wings). We have designed a general purpose cell marker for mosaic analysis. It consists of the bacterial LacZ gene expressed under the control of the constitutive promoter of the Drosophila armadillo gene. Transformants carrying this fusion gene express beta-galactosidase in all tissue and at all stages analyzed. Zygotic expression is detectable as early as gastrulation. In mosaics obtained by nuclear transplantation, cells carrying the transgene are easily distinguished from beta-galactosidase-negative host cells. The marker should also be useful for mosaics generated with the "Flp technique."

Animals↗
PubMed2000

Evidence for participation of RNA 1-encoded elicitor in Cowpea mosaic virus-mediated concurrent protection.

The cowpea (Vigna unguiculata) line Arlington, inoculated with Cowpea mosaic virus (CPMV), showed no symptoms, and no infectivity or accumulation of capsid antigen was detected at several days after inoculation. Coinoculation, but not sequential inoculation, of CPMV with similar concentrations of another Comovirus; Cowpea severe mosaic virus (CPSMV), resulted in reduced numbers of CPSMV-induced lesions. This apparent, CPMV-mediated reduction in number of CPSMV-induced infection centers was termed concurrent protection. We report results obtained by inoculating two nearly isogenic cowpea lines derived from a CPMV-susceptible cowpea crossed to Arlington, one line CPMV-susceptible and the other resistant. The CPMV virions B and M, encapsidating genomic RNAs 1 and 2, respectively, were extensively purified by gradient centrifugation. In the CPMV-resistant cowpea, either CPMV or CPMV B affected concurrent protection against CPSMV and against two distinct non-Comoviruses: Cherry leafroll virus and Southern bean mosaic virus. Adding CPMV M to the inoculum did not enhance CPMV-B-mediated protection. CPMV B was ineffective in protecting CPMV-susceptible cowpea. We postulate that CPMV-mediated concurrent protection is elicited in CPMV-resistant cowpea by a CPMV RNA-1-encoded factor and acts to reduce accumulation or spread of CPMV and certain coinoculated challenging viruses in or from the inoculated cell. Coinoculated CPMV did not protect CPMV-resistant cowpea against Tomato bushy stunt virus or Cucumber mosaic virus.

Comovirus↗
PubMed1981

Dermatoglyphic peculiarities in Down's syndrome detection of mosaicism and balanced translocation carriers.

The combination of dermatoglyphic patterns and the number and intensity of traits characteristic for Down's syndrome can be statistically expressed by the "Walker" index and the "general" index. More than 96% of a Down's syndrome series and a control series could clearly be separated by the general index. Cytogenetic and dermatoglyphic features were studied in 17 patients with mosaic trisomy 21 and their parents. In the 17 cytogenetically diagnosed patients with mosaic Down's syndrome, a highly significant correlation was observed between the percentage of trisomic cells and the presence of traits characteristic for this syndrome in the dermatoglyphic patterns. The diagnostic problems and the value of dermatoglyphic examination in cases of mosaicism, where the trisomic cell line seems to have disappeared, is discussed. The results of our study also indicate an elevated incidence of a specific dermatoglyphic pattern combination with general index values similar to Down's syndrome in one parent in nearly 20% of Down's syndrome children. The possibility of hidden mosaicism in these parents of Down's syndrome children is discussed. Furthermore, the dermatoglyphic patterns in a large kindred with an inherited 15/21 translocation (21/41 carriers of the balanced translocation; 14/41 chromosomally normal; 6/41 mongoloid members) was analyzed. The data obtained from this translocation family and especially the values obtained in the general index indicate that some dermatoglyphic stigmata are directly associated with the D/21 translocation carrier state and can therefore be used for predicting this state.

Chromosomes, Human, 13-15↗
PubMed1992

A proposal for a bean common mosaic subgroup of potyviruses.

In order to elucidate the taxonomic positions of bean common mosaic virus (BCMV) and blackeye cowpea mosaic virus (B1CMV), several strains of these viruses were compared on the basis of host ranges, antigenic properties established with antisera to virions and to N-terminal peptide domains of their coat proteins, and high performance liquid chromatographic peptide profiles. The comparison includes three strains of BCMV, viz. NL1, NL3 and NY15, four strains of B1CMV, viz. Fla, Ind, NR, and W, and the Moroccan isolate (Mor) of cowpea aphid-borne mosaic virus (CABMV), formerly designated as B1CMV-Mor. Based on these parameters, Fla, NR, and W are strains of one virus, whereas NL3, Ind and CABMV-Mor (and possibly NL1 and NY15) are separate viruses. In view of these characteristics which allow similar viruses to be separated, we propose that these viruses be included in a bean common mosaic subgroup of the genus Potyvirus.

Capsid↗
PubMed1992

Serological and biological relationships among viruses in the bean common mosaic virus subgroup.

Bean common mosaic virus (BCMV), blackeye cowpea mosaic virus (B1CMV), cowpea aphid-borne mosaic virus (CABMV), azuki bean mosaic virus (AzMV), and peanut stripe virus (PStV) are five species of the genus Potyvirus, family Potyviridae which are seed-transmitted in beans or cowpeas. Eighteen isolates of BCMV, five isolates of B1CMV, four isolates of CABMV, and one isolate each of AzMV, and PStV were compared serologically using a panel of 13 monoclonal antibodies (MAbs) raised against BCMV, B1CMV, CABMV, or PStV in indirect enzyme-linked immunosorbent assay (ELISA). Four MAbs detected all virus isolates; one detected all isolates except those of CABMV. Three MAbs were specific only for serotype A isolates of BCMV. Four MAbs detected all serotype B isolates of BCMV plus all isolates of B1CMV, AzMV, and PStV. None of the antibodies distinguished among these four viruses. However, in biological tests with 11 bean cultivars selected for differentiating BCMV pathotypes, all isolates of B1CMV, AzMV, and PStV could be differentiated from the BCMV serotype B isolates by their reactions on a few bean cultivars in host group I and the cowpea cultivar California Blackeye #5. Potential problems that can arise from the use of nonauthenticated isolates are also discussed.

Antibodies, Monoclonal↗
PubMed1994

Presence of chromosomal mosaicism in abnormal preimplantation embryos detected by fluorescence in situ hybridisation.

The extent of chromosomal mosaicism in human preimplantation embryos was examined using an improved procedure for the preparation and spreading of interphase nuclei for use in fluorescence in situ hybridisation, allowing the analysis of every nucleus within an embryo. One cell showed no hybridisation signals in only three of the 38 embryos that were included in this study, i.e. the hybridisation efficiency per successfully spread nucleus was 99% (197/200). Double-target in situ hybridisation analyses with X- and Y-chromosome-specific probes was performed to analyse nine embryos resulting from normal fertilisation, 22 polypronucleate embryos and seven cleavage-stage embryos where no (apronucleate) or only one pronucleus (monopronucleate) was observed. We also analysed autosomes 1 and 7 by double-target in situ hybridisation in the nuclei of two apronucleate, one monopronucleate and four polypronucleate embryos. All nine embryos that resulted from normal fertilisation were uniformly XY or XX. None of the apronucleate or monopronucleate embryos was haploid: three were diploid, one was triploid and three were mosaic. Fertilisation was detected by the presence of a Y-specific signal in four of these embryos. Of the polypronucleate embryos, two were diploid, two were triploid and 18 were mosaic for the sex chromosomes and/or autosomes 1 and 7. These results demonstrate that fertilisation sometimes occurs in monopronucleate embryos and that chromosomal mosaicism can be detected with high efficiency in apronucleate, monopronucleate and polypronucleate human embryos using fluorescence in situ hybridisation.

Blastocyst↗
PubMed1995

Interphase cytogenetics on paraffin-embedded sections of ovary for detection of genomic constitution in a patient with Turner's syndrome and chromosomal mosaicism.

The difficulty of detecting sex chromosome mosaicism cytogenetically hinders the finding of an acceptable explanation for phenotypic-genotypic discrepancy amongst those patients. Fluorescence in situ hybridization (FISH) permits the genomic identification of patients with mosaic karyotypes in interphase nuclei by utilising an X chromosome-specific DNA probe (interphase cytogenetics). We evaluated the efficiency of interphase cytogenetics in the detection of the genomic constitution of the ovary from a patient with Turner's syndrome having mosaicism (46,XX/45,X0) previously established by blood lymphocyte karyotyping. We used a biotin-labelled alphoid repetitive sequence, pBAMX5, specific for the centromeric region of the human X chromosome. Although examination of ovarian sections and blood lymphocytes by FISH showed the presence of both 46,XX and 45,X0 cell lines, the genomic constitution of the germ cells/oocytes in ovarian primordial follicles was shown to be normal (46,XX). Our results (1) show the high applicability of interphase cytogenetics on paraffin sections, (2) indicate the possibility of genomic screening of different tissues that are otherwise not amenable to routine cytogenetic investigation and (3) offer a reliable methodological approach to defining accurate by the percentage of abnormal karyotypes in mosaicism of different organs and non-dividing tissues.

Adult↗
PubMed1985

Trisomy 21 Down syndrome. Parental mosaicism.

The lymphocyte chromosomes of trisomy 21 Down syndrome patients and their parents in a random series of 374 families were analyzed, the objective being the identification of parental mosaicism. The numbers of parents in whom at least two trisomy 21 cells were detected were seven mothers and three fathers, a frequency of 2.7% of families. Confirmation of mosaicism was by identification of parental transmission of the extra chromosome to the progeny, by repeat chromosome analysis, and/or by the presence of more than one affected child. If to these are added six others in whom only one trisomic cell was detected, but with no other supporting evidence, the frequency could be as high as 4.3%. Differences in parental age at the birth of Down syndrome progeny may be accounted for by differences in frequencies of mosaicism in germ cells and somatic tissue. Mosaicism was found more frequently in the mothers than in the fathers, but more data are required for confirmation of a real difference.

Adult↗
PubMed1982

Mosaic trisomies in human spontaneous abortions.

Data from a cytogenetic survey of spontaneous abortions were examined to determine the incidence and origin of mosaic trisomies in this population. The overall frequency of mosaicism among trisomies was approximately 5%, but the level of mosaicism varied significantly among trisomies, being much higher for the nonacrocentric than for the acrocentric trisomies. Evidence from chromosome heteromorphism analysis suggests that the extra chromosome in mosaic trisomies usually has a meiotic origin.

Abortion, Spontaneous↗
PubMed1980

Trisomy 8. Report of a mosaic human male with near-normal phenotype and normal IQ, ascertained through infertility.

Trisomy 8, in mosaic or non-mosaic form is an extremely rare chromosomal condition in man. Liveborn subjects usually present with mental retardation, bone and joint anomalies and a variety of other physical anomalies. The mental retardation associated with the condition is, however, usually moderate compared to that found in other viable human autosomal trisomic conditions. The present report describes a trisomy 8 mosaic male subject with normal IQ and near-normal phenotype, ascertained through infertility. Chromosome studies on peripheral blood lymphocytes reveal a pure trisomy 8 constitution; cultured skin fibroblasts show 46,XY/47,XY+8 mosaicism. At meiosis, the extra No. 8 chromosome is missing from the germ line. The testicular histology indicates a germ cell maturation arrest in many spermatocytes and the patient is severely oligospermic. Biochemical studies to assay levels of glutathione reductase, a red cell enzyme, the gene for which resides in chromosome 8, show increased levels in the trisomy 8 patient compared with controls.

Adult↗
PubMed1994

RFLP analysis of chromosomal fragments in genetic mosaic strains of Bombyx mori.

Mottled striped (pSm), a genetic mosaic strain for larval body marking of the silkworm, Bombyx mori, contains a small chromosomal fragment generated by breakage near the end of the 2nd chromosome. This fragment carries the striped marking (pS) gene and part of the chorion gene clusters. To determine the structural features of this fragmented chromosome, we studied the organization of the chorion genes on the fragment using restriction fragment length polymorphism (RFLP) analysis. Two of three classes of chorion gene family probes detected RFLPs in the two phenotypes, pSm (p/p/pS), and p (p/p), which had lost the fragment, segregated among the siblings of a mottled striped strain. Although hybridization patterns were basically identical between them, one or two additional bands were always observed associating with the mosaic phenotype (pSm). This suggests that the additional bands correspond to extra copies of chorion genes on the chromosomal fragment, which have a different structure from ones on the intrinsic 2nd chromosomes. Such heterogeneity of chorion genes may have been maintained since the beginning of mosaic induction, due to the absence of recombinational events between the two chromosomes. We are unable to detect any RFLPs by hybridization with the early class of chorion genes, implying that chromosomal breakage might have occurred between the two chorion clusters, Chl-2 and Ch3, which are located approximately 4 cM apart from each other. Based on RFLP analyses for two independent mosaic strains (788 and 872), we postulate a common chromosomal origin with independent breakpoints and construct structural models for the two kinds of chromosomal fragments.

Animals↗