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 739 records · Page 41Linked to original sources
PubMed2004

Discrepancy between the fetus and extra-embryonic tissues in prenatally detected mosaic distal 5p deletion.

Discrepancy between the fetus and extra-embryonic tissues in prenatally detected mosaic distal 5p deletion: We present clinical and cytogenetic data on a second-trimester fetus with mosaic del(5)(p15.1) and the extra-embryonic tissues with a normal karyotype. A 34-year-old woman, gravida 2, para 0, underwent genetic amniocentesis at 20 weeks' gestation because of advanced maternal age. Cytogenetic analysis of the cultured amniocytes revealed mosaicism for a distal 5p deletion, mos 46,XY,del(5)(p15.1)[4]/46,XY[26]. The pregnancy was terminated subsequently. Postnatally, the fetus displayed a triangular face, hypertelorism, epicanthal folds, low-set ears, and micrognathia. A karyotype of mos 46,XY,del(5)(pl 5.1)/46,XY was found in the liver, lungs, skin, and cord blood, whereas, the placenta, amnion, and umbilical cord had a karyotype of 46,XY. Our observation of fetoplacental, fetoamniotic, and fetoumbilical discrepancies shows a limitation of using placenta, amnion, and umbilical cord as confirmatory tools for prenatally detected mosaic distal 5p deletion. Our case also reinforces the notion that amniocentesis offers a more reliable diagnosis, compared to chorionic villus sampling.

Adult↗
PubMed2004

Occurrence, distribution and relative incidence of mosaic viruses infecting field--grown squash in Tehran province, Iran.

Squash (Cucurbita pepo) belongs to Cucurbitaceae family. Every year Cucurbitaceae are planted world wide. They are one of the most important economic crops. Cucurbitaceae are threatened by viruses. Many viruses damage the plants of this family. Since nine viruses have been reported on squash from Iran. In this survey, during 2002--2003, to determine the distribution of Cucumber mosaic virus (CMV), Zucchini yellow mosaic virus (ZYMV) and Watermelon mosaic virus (WMV), 466 samples were collected from squash field in Tehran province. Infected plants showing symptoms such as: mosaic, yellowing, deformation, shoestring of leaves and fruit deformation and yield reduction. Distribution of CMV, ZYMV and WMV were determined by DAS-ELISA. Thepercentage of ZYMV, WMV and CMV were 35.6, 26.1 and 25.1% respectively. Triple infection (CMV+ZYMV+WMV) were found in 6.4% of samples. ZYMV were found the most frequently the viruses. This is the first report of WMV on squash in Tehran province.

Cucumovirus↗
PubMed2006

Time-resolved fluorescence detection of mosaic DNA chip.

We demonstrated a time-resolved fluorescence (TRF) label and detection of mosaic DNA chip in this paper. We synthesized oligonucleotide sequences in situ on glass slides directly, and then sliced them up into small pieces and patched up the pieces bearing different sequences to generate a mosaic DNA chip. With multiple 4, 7-bis(chlorosulfophenyl)-1, 10-phenanthroline-2, 9-dicarboxylic acid (BCPDA, abbreviated as BCPDA) labeling method based on avidin-biotin amplification, we established a TRF detection format on the mosaic DNA chip. The detection method allows discriminatory signals for perfect match, one-base mismatch, two-base mismatch, and three-base mismatch by TRF labeled DNA hybridization, whereby Europium (III, Eu3+) was captured and released on the principle of complexation and dissociation interaction between BCPDA and Eu3+ solution when the BCPDA-tagged avidin and biotin-capped oligonucleotide sequence linked. The fluorescence spectra and related lifetimes were determined. We also compared the TRF detection mode with the conventional fluorescence one. These results showed the former is a potential alternative replacement of the latter, especially for labeling the mosaic DNA chip. The discovery is of fundamental interest and has significant implications to biochips and biosensors based on time-resolved-fluorescence detection.

Avidin↗
PubMed2006

Prenatal diagnosis of mosaicism identified in amniotic fluid cell cultures.

Chromosomal mosaicism in prenatal diagnosis is an important problem to be solved immediately and the probable phenotypic reflections should be explained to the family. We report two numerical and two structural mosaicisms detected in amniocyte cultures. The first fetus had a 47,XY,+mar[10]/46,XY[10] karyotype. The marker chromosome was shown to be derived from chromosome 15 by FISH method. The newborn had intrauterine growth retardation and cerebral thrombosis and died at the 29th day of age. The second fetus had a 45,X[4]/46,XX[26] karyotype. The parents refused cordocentesis and decided to terminate pregnancy in the 21st week. The third case, presented with bilateral large choroid plexus cysts, had a 46,XX, dup(1)(q22-q32)[9]/46,XX[21] karyotype. The parents' karyotypes were normal and the pregnancy was aborted in the 23rd week of gestation. The second structural abnormality was reported as 46,XX,t(6;11)(q23; p13)[3]/46,XX[20]. The mosaicism was detected in only one flask. The parents decided to continue pregnancy and cordocentesis could not be performed due to the fetal and placental position. The baby was born at term. Peripheral blood lymphocyte culture resulted in a 46,XX normal karyotype. Information and risks were explained to all families during genetic counseling. Mosaicism in prenatal diagnosis needs both detailed examination and follow up, since clinical findings depend on the type of abnormality.

Adult↗
PubMed1991

Mental development in Down syndrome mosaicism.

Serial assessments of mental status of 30 subjects with Down syndrome mosaicism were compared with those of 30 subjects with trisomy 21 Down syndrome. The samples were matched for age, sex, and parental socioeconomic background. The mean IQ level of the mosaic Down syndrome group was significantly higher than that of the trisomy 21 group. Many subjects with mosaicism showed better verbal abilities, and some also demonstrated normal visual-perceptual skills in paper- and-pencil tasks. Children with Down syndrome with IQs over 60 at 5 years of age and with relatively normal speech can be viewed as a suspected case of mosaicism. Chromosomal analysis is mandatory to confirm or disprove this diagnosis.

Adolescent↗
PubMed1990

Mosaicism in chorionic villus sampling: an association with poor perinatal outcome.

Prenatal diagnosis by first-trimester chorionic villus sampling was successful in 4319 pregnancies involving 4395 fetuses. Cytogenetic information was obtained by both rapid cytotrophoblastic preparation and monolayer mesenchymal tissue culture. Chromosomal mosaicism was present in 55 of 4319 (1.3%). The abnormal cell line involved the cytotrophoblast in 79.6% of the mosaic specimens. None of the abnormalities found in the cytotrophoblast were confirmed in the fetus when the tissue culture was normal, supporting the belief that the cells of the mesenchymal core more truly reflect the chromosomal constitution of the fetus. However, a significant increase in the perinatal loss rate in the placental mosaic group was noted when compared with the nonmosaics: 16.7 versus 2.7% (P = .0001). These findings suggest that placental mosaicism may be a cause of perinatal loss.

Abortion, Spontaneous↗
PubMed1986

Klinefelter's syndrome, mosaic 46,XX/46,XY/47,XXY/48,XXXY/48,XXYY: a case report.

A 35-year-old male was investigated for primary infertility. Clinical examination showed an intelligent man with normal facial appearance and moustache and small firm testes. Testicular histopathology revealed marked atrophy of the testes with no spermatogenesis and absence of germ cells. Hormonal profile showed elevated levels of FSH,LH and low levels of testosterone. Chromosome analysis from whole blood culture showed cells with 46,XX/46,XY/47,XXY/48,XXXY/48,XXYY mosaicism. The predominant cell line was 47,XXY (87.86%). 46,XY/47,XXY mosaicism is not uncommon. However, mosaicism of multiple sex chromosome aneuploidy is rarely observed. This is the first report of mosaicism in Klinefelter's syndrome variant with five cell lines.

Adult↗
PubMed1985

[45,X/46,X,del(Yq) sex chromosome mosaicism--analysis of the phenotypic expression].

Three female patients with Turner-syndrome (sexual infantilism, short stature and somatic Turner-stigmata) have been analysed cytogenetically by means of different banding techniques. A deletion of the distal heterochromatic band Yq12 of the Y chromosome was observed in a mosaic with a 45,X-cell line, i.e. the karyotype is 45,X/46,X,del(Y)(q12). In order to get information about the phenotypic expression of the 45,X/46,X,del(Yq) mosaicism all previously published cases have been reviewed. Comparing the phenotypes of all 45,X/46,X,del(Yq) mosaic cases three different phenotype categories of sexual development can be distinguished: female individuals with sexual infantilism and Turner-stigmata, individuals with ambiguous genitals, ranging from clitoris hypertrophy of female genitals to hypospadia of males, male individuals, who are infertile (azoospermic). A comparison of the appearance of external genitals with the status of gonads of all patients revealed an unequivocal relationship between the gonad status and the resulting phenotype category. Furthermore, the role of Y-chromosomal loci determining testicular differentiation (biological function of H-Y antigen) for male development has been emphasized. The effect of the 45,X-cell line on the expression of short stature and somatic Turner-stigmata is independent of sexual development. Considering the great phenotypic variability of the 45,X/46,X,del(Yq) mosaicism it seems impossible to deduce a definitive phenotype. This problem is acute in prenatal diagnosis especially.

Adolescent↗
PubMed1979

Chromosomal mosaicism in amniotic fluid cell cultures.

Over the past 6 years, using in situ processing methods, we have identified 32 cases of mosaicism in amniotic fluid cell cultures prepared from 1,100 samples. Two of these (45,X/46,XX and 46,XX/47,XX, + 21) were called true mosaics because multiple colonies demonstrated the same abnormal chromosome complement, and on subsequent evaluation of the newborn blood or fetal tissues, mosaicism was confirmed. Of the remaining cases, 29 were designated as pseudomosaics because only single or partial colonies exhibited an aberrant chromosome complement, 12 having a trisomy 2 line. In the final case, a double trisomy was demonstrated in only one of eight colonies in the first culture, but in the culture from a repeat sample an additional two colonies showed the same double trisomy. Since no abnormal cells were observed in infant blood, it was postulated that the mosaicism may only have been present in the extraembryonic tissues. It is our conviction that the use of these cloning methods should diminish the danger of misdiagnosis in genetic amniocentesis.

Amniotic Fluid↗
PubMed1978

Mosaic autosomal trisomy in cultures from spontaneous abortions.

In a consecutive series of 592 karyotyped spontaneous abortions, ten of 103 autosomal trisomies were mosaic, with a normal cell line also present. The frequency of mosaicism (10%) is much higher than that reported in Down syndrome, but similar to that reported in amniotic fluid cultures and in induced abortions. The most likely explanations for this discrepancy are (1) previous underestimation of mosaicism in live births or (2) mosaicism which is often restricted to extraembryonic fetal tissue.

Abortion, Spontaneous↗
PubMed1982

Studies of tumor cell origins in mosaics.

The available data on chemical carcinogenesis with methylcholanthrene in mosaic mice and studies of atherosclerotic plaques in human and experimental animal G6PD mosaics have been reviewed. The MC studies in two different kinds of mosaic mice demonstrate the importance of understanding normal tissue architecture before making inferences regarding the cellular kinetics of tumor origin. The analysis of the MC studies also indicates a large cellular target size for this carcinogen. The current data on atheromas in mosaic humans and animals do not support the classical idea of an injury-repair mechanism of plaque origin, and leave the possibility open that the monoclonal tendency of atheromas could indicate a tumorigenic type of mechanism in their development.

Animals↗
PubMedDate not supplied

Chromosome and interphase analysis of placental mosaicism in intrauterine growth retardation.

Confined placental mosaicism is found in a higher percentage of cases of unexplained intrauterine growth retardation (IUGR) than in those of normal pregnancies. To test this hypothesis of cytogenetically abnormal placental cells associated with IUGR, we identified patients in whose fetuses IUGR was suspected during the antepartum period by clinical and serial ultrasonography and Doppler examinations and confirmed by immediate neonatal physical examination. At birth placental biopsy samples and cord blood were collected and coded. Similar specimens were obtained from non-IUGR pregnancies during that period to avoid bias in evaluation of results. These specimens were processed for standard cytogenetic studies and fluorescent in situ hybridization (FISH) of interphase cells to detect any chromosomal mosaicism in a double-blind fashion. Results were obtained on 26 IUGR placentas. Of these placentas, 22 were cytogenetically normal on standard karyotype analysis and interphase fluorescent studies. Four placentas were shown to have some chromosomal aneuploidy: one with the same chromosome anomaly in multiple cells and the other with multiple single-cell aneuploidy. Of these placentas, cytogenetic and FISH studies showed one to have a monosomy 21 cell line, two placentas showed mosaicism on karyotyping, which was not confirmed by FISH, and one placenta had a suggested chromosomal instability. All placentas had normal anatomy regardless of the chromosome findings and no chromosome anomalies were seen in any of the infants. Non-IUGR placentas showed no chromosomal-confined mosaicism and all had normal findings on placental pathologic examination.

Aneuploidy↗
PubMed1994

Somatic mosaicism for a newly identified splice-site mutation in a patient with adenosine deaminase-deficient immunodeficiency and spontaneous clinical recovery.

Absent or severely reduced adenosine deaminase (ADA) activity produces inherited immunodeficiency of varying severity, with defects of both cellular and humoral immunity. We report somatic mosaicism as the basis for a delayed presentation and unusual course of a currently healthy young adult receiving no therapy. He was diagnosed at age 2 1/2 years because of life-threatening pneumonia, recurrent infections, failure of normal growth, and lymphopenia, but he retained significant cellular immune function. A fibroblast cell line and a B cell line, established at diagnosis, lacked ADA activity and were heteroallelic for splice-donor-site mutation in IVS 1 (+1GT-->CT) and a missense mutation (Arg101Gln). All clones (17/17) isolated from the B cell mRNA carried the missense mutation, indicating that the allele with the splice-site mutation produced unstable mRNA. In striking contrast, a B cell line established at age 16 years expressed 50% of normal ADA; 50% of ADA mRNA had normal sequence, and 50% had the missense mutation. Genomic DNA contained the missense mutation but not the splice-site mutation. All three cell lines were identical for multiple polymorphic markers and the presence of a Y chromosome. In vivo somatic mosaicism was demonstrated in genomic DNA from peripheral blood cells obtained at 16 years of age, in that less than half the DNA carried the splice-site mutation (P < .002, vs. original B cell line). Consistent with mosaicism, erythrocyte content of the toxic metabolite deoxyATP was only minimally elevated. Somatic mosaicism could have arisen either by somatic mutation or by reversion at the site of mutation. Selection in vivo for ADA normal hematopoietic cells may have played a role in the return to normal health, in the absence of therapy.

Adenosine Deaminase↗
PubMed1996

Somatic mosaicism in a patient with neurofibromatosis type 1.

Using loss of heterozygosity analysis, a method designed to detect moderate to large gene deletions, we have identified a new-mutation neurofibromatosis type 1 (NF1) patient who is somatically mosaic for a large maternally derived deletion in the NF1 gene region. The deletion extends at least from exon 4 near the 5' end of the gene to intron 39 near the 3' end. The gene-coding region is, therefore, mostly or entirely deleted, encompassing a loss of > or = 100 kb. We hypothesize that the deletion occurred at a relatively early developmental timepoint, since signs of NF1 in this patient are not confined to a specific body region, as seen in "segmental" NF, and since both mesodermally and ectodermally derived cells are affected. This report provides the first molecular evidence of somatic mosaicism in NF1 and, taken together with a recent report of germ-line mosaicism in NF1, adds credence to the concept that mosaicism plays an important role in phenotypic and genetic aspects of NF1 and may even be a relatively common phenomenon.

Adult↗
PubMedDate not supplied

[Disordered development of Drosophila melanogaster embryos mosaic for the Notch gene].

Gene Notch codes for a transmembrane protein, which is involved in cell interactions: mutations in Notch locus result in differentiation of all cells of the ventral and anterodorsal ectoderm into neuroblasts. In order to examine interrelations between cells of the normal and mutant phenotype, mosaic embryos were obtained. Procephalic regions of Drosophila trunk were most strongly affected in the experimental, as well as in the control, embryos. In control mosaics, the absence of anterodorsal ectoderm was accompanied by a decrease in the size of epipharyngeal ganglion, whereas Notch mosaics, in contrast, showed the expansion of epipharyngeal ganglion over dorsal ectoderm up to the posterior end of the embryo. Differentiation abnormalities of cells of the ventral ectoderm in Notch mosaics were rarer. Generally, the results of our experiments lead to a hypothesis about the presence of a certain threshold in the proportion between Notch cells and wild-type cells in ventral ectoderm. When this threshold value is exceeded, all cells of ventral ectoderm differentiate into neuroblasts.

Animals↗
PubMed1997

Mosaicism in trisomy 8: phenotype differences according to tissular repartition of normal and trisomic clones.

Three new observations of trisomy 8 mosaicism are presented. In two postnatal cases, both patients showed agenesis of corpus callosum associated with different clinical findings. In a third case, the prenatal diagnosis revealed trisomy 8 mosaicism exclusively in chorionic villi (CV) cells long term culture. Normal results were obtained in CV direct preparation and in cultured amniotic cells. In lymphocytes, the child showed low level trisomy 8 mosaicism. The only clinical findings were deep palmar and plantar furrows. The present cases as well as reports in the literature indicate that the variation in tissular repartition of normal and trisomic clones in trisomy 8 mosaicism is possibly responsible for the missing correlation between cytogenetic findings and clinical severity in this syndrome.

Child, Preschool↗
PubMed1998

Monozygotic twins with 45,X/46,XY mosaicism discordant for phenotypic sex.

We report on two sets of monozygotic twins (MZTs) discordant for phenotypic sex ascertained at birth when the female twin was noted to have signs of the Ullrich-Turner syndrome. Cytogenetic investigations on the female of the first pair showed 45,X/46,XY mosaicism in lymphocytes but fibroblasts grown from two skin biopsies at separate sites and from gonadal tissue showed only 45,X cells. The male showed mosaicism in both blood lymphocytes and skin fibroblasts. In the second family, both twins also showed mosaicism in lymphocytes. The female had a 45,X karyotype in fibroblasts from skin and gonadal tissue, but in contrast to the first family, the male twin had a normal male karyotype in fibroblasts from skin biopsy and from connective tissue adjacent to the vas deferens. Discordant phenotypic sex in monozygotic twins is rare. As in our cases, the nine previously reported sets of MZTs all had mosaicism for sex chromosome abnormalities. A mitotic error leading to the loss of a Y chromosome prior to, accompanying, or following the twinning process would account for the reported combinations of karyotypes.

Female↗
PubMed1998

Dilemma of trisomy 20 mosaicism detected prenatally: is it an innocent finding?

The clinical significance of mosaicism trisomy 20 detected prenatally following amniocentesis remains uncertain, due to the rarity of liveborn cases with inconsistent clinical findings, the short postnatal follow-up, and failure in evaluating other fetal tissues for the presence of the trisomy. We report on a 15 month-old 46,XX chromosome constitution in white blood cells, while skin fibroblasts demonstrated trisomy 20 mosaicism (54%) by fluorescence in situ hybridization (FISH) analysis. Clinical examination of the baby showed only minor phenotypic signs (bilateral epicanthal folds, delayed closure of fontanel with no other gross anomalies), but demonstrated a considerable developmental delay in gross and fine motor skills along with hypotonicity. This is the second oldest described liveborn with trisomy 20 mosaicism confirmed in skin fibroblasts. This cytogenetic aberration along with her developmental delay suggests that the two findings are related and that aberration affects various fetal tissues and is not confined to extra-embryonic tissue as suggested previously. Yet, an undiagnosed condition may be the cause of the child's developmental delay. Based on this case and following a review of the literature we suggest that when mosaic trisomy 20 is identified in amniocytes, further evaluation is required. Cord blood should be analyzed preferably by FISH. During counseling the parents should be advised of an additional risk, such as developmental delay, even when fetal cord karyotype and detailed ultrasonic scan are normal.

Chromosomes, Human, Pair 20↗