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Amniotic Fluid Cells (amniotic + fluid_cell)

Distribution by Scientific Domains

Life Sciences	90%

Selected Abstracts

Shedding new light on false positive diagnosis of trisomy 21 by fluorescence in situ hybridization (FISH) on uncultured amniotic fluid cells: experiences from two Canadian cytogenetic laboratories

PRENATAL DIAGNOSIS, Issue 10 2007
Jia-Chi Wang
No abstract is available for this article. [source]

Prenatal diagnosis of free sialic acid storage disorders (SASD)

PRENATAL DIAGNOSIS, Issue 8 2006
Nina Aula
Abstract Free sialic acid storage disorders, Salla disease (SD) and Infantile sialic acid storage disease (ISSD), are lysosomal storage diseases due to impaired function of a sialic acid transporter, sialin, at the lysosomal membrane. Several mutations of the sialin gene, SLC17A5, are known, leading either to the severe neonatal/infantile disease or to the milder, adult-type developmental disorder, Salla disease. Free sialic acid accumulation in lysosomes causes increased tissue concentration and consequently elevated urinary excretion. Prenatal diagnosis of SASD is possible either by determination of free sialic acid concentration or by mutation analysis of the SLC17A5 gene in fetal specimen, in chorionic villus biopsy particularly. Both techniques have been successfully applied in several cases, sialic acid assay more often in ISSD cases but mutation analysis preferentially in SD. Sialic acid assay of amniotic fluid supernatant or cultured amniotic fluid cells may give erroneous results and should not be used for prenatal diagnosis of these disorders. The present comments are mainly based on our experience of prenatal diagnosis of SD in Finnish families. A founder mutation in SLC17A5 gene, 115C-> T, represents 95% of the disease alleles in the Finnish SD patients, which provides a unique possibility to apply mutation analysis. Therefore, molecular studies have successfully been used in 17 families since the identification of the gene and the characterization of the SD mutations. Earlier, eight prenatal studies were performed by measuring the free sialic acid concentration in chorionic villus samples. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Complex de novo cryptic subtelomeric rearrangements in a fetus with multiple ultrasonographic abnormalities and a normal karyotype at amniocentesis

PRENATAL DIAGNOSIS, Issue 12 2005
M. Anwar Iqbal
Abstract Objective Prenatal diagnosis is usually offered to the majority of pregnancies with fetal structural abnormalities detected by prenatal ultrasound; however, only a small proportion show an abnormal karyotype. We wanted to detect cryptic subtelomeric rearrangements (CSTR) in a fetus with multiple abnormal ultrasonographic findings that revealed a normal karyotype at amniocentesis. Methods Fetal chromosome analysis was performed from amniotic fluid cells. Parental chromosome analysis was done on PHA stimulated lymphocyte cultures. For fluorescence in situ hybridization (FISH) analysis, ToTelVysion multicolor DNA probe mixture was used to hybridize the p and q telomeres of each chromosome. Results The amniotic fluid chromosome analysis revealed an apparently normal 46,XY karyotype. A follow-up FISH analysis showed three apparently balanced complex translocations involving (1) the chromosome 4p and 22q telomeres (2) 4q and 11q telomeres and (3) 8p, 20p and 20q telomeres. Parental chromosome and subtelomere FISH analysis was found to be normal. Conclusion To our knowledge, this is the first report of complex de novo cryptic translocations in an abnormal fetus. These CSTR identified by FISH with subtelomere-specific probes are not detected by other cytogenetic and/or molecular cytogenetic approaches. However, to confirm the balanced nature of CSTR, array-CGH can be helpful. Further studies are in progress to determine the frequency of CSTR and its significance in the etiology of fetal abnormalities. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Precise prenatal diagnosis of tuberous sclerosis by sequencing the TSC2 gene

PRENATAL DIAGNOSIS, Issue 7 2005
Aubrey Milunsky
Abstract Background The presumptive prenatal diagnosis of tuberous sclerosis (TSC) previously depended upon fetal imaging. Cloning of the two TSC genes (TSC1 and TSC2) now enables precise molecular diagnosis by gene sequencing. We used this approach for the prenatal diagnosis of a fetus showing multiple intracardiac tumors. Methods DNA extracted from cultivated amniotic fluid cells underwent sequencing of all coding regions and exon-intron boundaries of the TSC1 and TSC2 genes. Results A mutation (R611Q) was found in exon 16 of the TSC2 gene. Thus far, neither clinically unaffected parents has provided blood samples for mutation analysis. Conclusion For the first time, mutation analysis of a TSC gene enabled a precise prenatal diagnosis. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Prenatal diagnosis of mosaic ring chromosome 22 associated with cardiovascular abnormalities and intrauterine growth restriction

PRENATAL DIAGNOSIS, Issue 1 2003
Chih-Ping Chen
Abstract Objectives To present the prenatal diagnosis and perinatal findings of mosaic ring chromosome 22. Case Amniocentesis was performed at 18 gestational weeks because of an advanced maternal age. Cytogenetic analysis of the cultured amniotic fluid cells revealed mosaicism for ring chromosome 22, 45,XX,-22[6]/46,XX,r(22)(p13q13.31)[15]. Abnormal fetal sonographic findings included small for gestational age, a ventricular septal defect, and truncus arteriosus. The pregnancy was terminated. Additional phenotypic findings included hypertelorism, epicanthal folds, and abnormal ears. Cytogenetic analysis of the cord blood lymphocytes revealed a complex mosaic karyotype, 45,XX,-22[7]/46,XX,r(22)(p13q13.31)[82]/46,XX,idic r(22)(p13q13.31;p13q13.31)[11]. Cytogenetic analysis of the hepatocytes also revealed mosaic r(22) with mosaicism for idic r(22) and monosomy 22. The deletion of distal 22q and the duplication of 22q11.2 on idic r(22), and the distal 22q deletion on r(22) were demonstrated by fluorescent in situ hybridization (FISH) analysis using 22q terminal probes at 22q13 and a DiGeorge syndrome critical region probe at 22q11.2. The breakpoint on distal 22q13 and the extent of the duplication of 22q on idic r(22) was determined by examining polymorphic markers specific for chromosome 22 using quantitative fluorescent polymerase chain reaction assays. The chromosomal aberration was of maternal origin. Conclusion Molecular and FISH studies allow a better delineation of some prenatally detected aneuploidy syndromes and help elucidate the genetic pathogenesis. Fetuses having mosaic r(22) with a low level mosaicism for r(22) duplication/deletion may present cardiovascular abnormalities and intrauterine growth restriction on prenatal ultrasound. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Prenatal diagnosis of the Dandy-Walker malformation and ventriculomegaly associated with partial trisomy 9p and distal 12p deletion

PRENATAL DIAGNOSIS, Issue 12 2002
Chih-Ping Chen
Abstract Objectives To present the prenatal diagnosis and perinatal findings of partial trisomy 9p and distal 12p deletion. Methods and results Amniocentesis was performed at 17 gestational weeks due to a balanced reciprocal translocation t(9;12)(p11.2;p13.3) in the mother. The father's karyotype was normal. The family had a 5-year-old daughter with a Dandy-Walker malformation and a trisomy 9p syndrome. Cytogenetic analysis of the cultured amniotic fluid cells revealed a 46,XY,der(12)t(9;12)(p11.2;p13.3)mat karyotype with partial monosomy 12p(12pter,p13.3) and partial trisomy 9p(9pter,p11.2). Sonographic examination of the fetal brain and skull showed bilateral ventriculomegaly, brachycephaly and a Dandy-Walker malformation with an enlarged cisterna magna and absence of the cerebellar vermis. The pregnancy was terminated subsequently. At autopsy, the proband manifested agenesis of the cerebellar vermis and a typical trisomy 9p phenotype. Conclusion Fetuses with partial trisomy 9p(9pter,p11.2) may present a Dandy-Walker malformation and ventriculomegaly on prenatal ultrasound in the second trimester. A dosage effect of genes located on 9pter,p11.2 may be associated with the abnormal development of the central nervous system in patients with partial or complete trisomy 9. Copyright © 2002 John Wiley & Sons, Ltd. [source]

The effect of fast reporting by amnio-PCR on anxiety levels in women with positive biochemical screening for Down syndrome , a randomized controlled trial

PRENATAL DIAGNOSIS, Issue 3 2002
Wing Cheong Leung
Abstract Objective To study the effect of fast reporting by polymerase chain reaction on amniotic fluid cells (amnio-PCR) on anxiety levels in women with positive biochemical screening for Down syndrome. Method Between May 2000 and April 2001, 60 screen-positive women were randomized before amniocentesis into either having (group A) or not having (group B) fast-reporting by amnio-PCR. Anxiety levels were measured by the Spielberger State-Trait Anxiety Inventory just prior to amniocentesis, three days (when PCR results were known to group A) and three weeks (when standard karyotype results were known to both groups) afterwards. Results Two women were excluded because in one woman amnio-PCR showed trisomy 21 and the other miscarried shortly after amniocentesis. The state-anxiety scores increased over the three-week period after being informed of the positive-screen result in both groups. The trait- and state-anxiety scores at all points did not differ between the two groups. Conclusions In contrast to the general belief, fast reporting by amnio-PCR did not alleviate anxiety in women who are screen-positive for Down syndrome. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Ring chromosome 6 in three fetuses: Case reports, literature review, and implications for prenatal diagnosis

AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 2 2002
Maik Urban
Abstract Prenatal and postnatal findings in three fetuses with a ring chromosome 6 are presented, and the literature of this rare cytogenetic disorder is reviewed. The described fetuses illustrate the broad spectrum of the clinical manifestation of ring chromosome 6. In one fetus, the disorder was diagnosed incidentally by a routine amniocentesis due to advanced maternal age. The other two fetuses were hydrocephalic and had other congenital anomalies. Remarkably, the ring chromosome 6 tends to disappear in cultured amniotic fluid cells; karyotyping revealed complete or nearly complete monosomy 6. In contrast, the ring was preserved in high proportions of fetal leukocytes. Postnatal growth retardation is the only consistent finding of this chromosomal disorder. Maternal age is not significantly above average. An additional review of 20 literature cases revealed a striking tendency to hydrocephalus, either due to deficient brain growth or secondary to an aqueductal stenosis. Children with hydrocephalus and ring chromosme 6 tend to display facial dysmorphism and may have additional malformations, growth failure, eye anomalies, and seizures. In contrast, there are two reports on children with a ring chromosome 6 who had short stature, normal appearance, and a normal or almost-normal psychomotor development. In such patients at the mild end of the clinical spectrum, the phenotype is basically restricted to what Kosztolányi. [1987: Hum Genet 75:174,179] delineated as "ring syndrome," comprising "severe growth failure without major malformations, without a specific deletion syndrome, with only a few or no minor anomalies, and mild to moderate mental retardation." This "ring syndrome" is considered to occur independently of the autosome involved in the ring formation. The overall impression from our cases and from the literature review of cases with ring chromosome 6 is that the karyotype-genotype correlation is poor. This makes prognostic counseling of parents difficult and unsatisfactory. Serial targeted ultrasound examinations, especially of the brain, are decisive factors in elucidating the prognosis. © 2002 Wiley-Liss, Inc. [source]

Fetal RHD genotyping in maternal serum during the first trimester of pregnancy

BRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2002
Jean-Marc Costa
Summary., Fetal RHD genotype determination is useful in the management of sensitized RhD-negative pregnant women. It can be ascertained early during pregnancy by chorionic villus sampling (CVS) or amniocentesis. However, these procedures are invasive, resulting both in an increased risk of fetal loss and in an increased severity of immunization due to fetomaternal haemorrhage. A reliable determination of RHD genotype by fetal DNA analysis in maternal serum during the first trimester of pregnancy is reported in this study. One hundred and six sera from RhD-negative pregnant women were obtained during the first trimester of pregnancy. These sera were tested for the presence of RHD gene using a new real-time polymerase chain reaction assay and the results compared with those obtained later in pregnancy on amniotic fluid cells and by RHD serology of the new-born. All sera from women carrying a RhD-positive fetus (n = 62) gave positive results for RHD gene detection and sera from women carrying a RhD-negative fetus (n = 40) were negative. The high level of accuracy of fetal RHD genotyping obtained in this study could enable this technique to be offered on a routine basis for the management of RhD-negative patients during the first trimester of pregnancy. [source]

Modifications in cell cycle kinetics and in expression of G1 phase-regulating proteins in human amniotic cells after exposure to electromagnetic fields and ionizing radiation

CELL PROLIFERATION, Issue 5 2004
S. Lange
Because development of cancer is associated with deregulated cell growth and we previously observed a magnetic field-induced decrease in DNA synthesis [Lange et al. (2002) Alterations in the cell cycle and in the protein level of cyclin D1p, 21CIP1, and p16INK4a after exposure to 50 HZ. MF in human cells. Radiat. Environ. Biophys.41, 131], this study aims to document the influence of 50 Hz, 1 mT magnetic fields (MF), with or without initial ,-ionizing radiation (IR), on the following cell proliferation-relevant parameters in human amniotic fluid cells (AFC): cell cycle distribution, expression of the G1 phase-regulating proteins Cdk4, cyclin D1, p21CIP1 and p16INK4a, and Cdk4 activity. While IR induced a G1 delay and a dose-dependent G2 arrest, no discernible changes in cell cycle kinetics were observed due to MF exposure. However, a significant decrease in the protein expression of cyclin D1 and an increase in p21CIP1 - and p16INK4a -expression could be detected after exposure to MF alone. IR-exposure caused an augmentation of p21CIP1 - and p16INK4a - levels as well, but did not alter cyclin D1 expression. A slight diminution of Cdk4 activity was noticed after MF exposure only, indicating that Cdk4 appears not to act as a mediator of MF- or IR-induced changes in the cell cycle of AFC cells. Co-exposure to MF/IR affected neither cell cycle distribution nor protein expression or kinase activity additionally or synergistically, and therefore MF seems not to modify the mutagenic potency of IR. [source]