First trimester maternal serum placenta growth factor (PIGF)concentrations in pregnancies with fetal trisomy 21 or trisomy 18.

Placenta growth factor (PIGF), an angiogenic factor belonging to the vascular endothelial growth factor family, pregnancy-associated plasma protein A (PAPP-A) and free beta-human chorionic gonadotrophin (beta-hCG) were measured in maternal serum from 45 pregnancies with trisomy 21, 45 with trisomy 18 and 493 normal controls at 10-13 completed weeks of gestation. In the normal pregnancies maternal serum PIGF levels increased exponentially with gestation. The median multiple of the median (MoM) PIGF concentration in the trisomy 21 group (1.26 MoM) was significantly higher (p<0.0001) than in the control group (1.00 MoM). In the trisomy 18 group the median PIGF was lower (0.889 MoM) but this did not quite reach significance (p=0.064). The corresponding median MoM values for PAPP-A were 1.00 MoM for the controls, 0.49 MoM for trisomy 21 and 0.16 MoM for trisomy 18. The median MoM values for free beta-hCG were 1.00 MoM for the controls, 2.05 MoM for trisomy 21 and 0.38 MoM for trisomy 18. In the control group there was a small but significant correlation of PIGF with free beta-hCG (r=+0.1024) and PAPP-A (r=+0.2288). In the trisomy 18 group there was a significant association between PIGF and free beta-hCG (r=+0.2629) but not with PAPP-A (r=+0.0038). In the trisomy 21 group there was a small but significant association with PAPP-A (r=+0.1028) but not with free beta-hCG (r=+0.0339). The separation of affected and unaffected pregnancies in maternal serum PIGF is small, and therefore it is unlikely that measurement of PIGF would improve screening for these abnormalities provided by the combination of fetal nuchal translucency and maternal serum PAPP-A and free beta-hCG.

Microsatellite analysis provides efficient confirmation of fetal trophoblast isolation from maternal circulation.

Fetal trophoblasts can be found in maternal circulation from an early stage of pregnancy and thus provide a potential source of DNA for non-invasive prenatal diagnosis. We have developed a two-step method for trophoblast isolation between the 8th and 12th week of pregnancy. Blood was sampled from 14 women undergoing termination of pregnancy or spontaneous abortion. Immunomagnetic beads precoated with HLA class I and II, and with anti-cytokeratin-18 monoclonal antibodies, were used to remove CD8+ and other maternal cells, and to select for fetal trophoblasts, respectively. Microsatellite analysis was performed on DNA extracted from the isolated, maternal, paternal and placental cells after PCR amplification. Recovery of the trophoblasts was confirmed in 13/14 cases (93%) by the identification of an identical microsatellite pattern for fetal and placental cells. Further evidence was the presence of heterozygous alleles of both maternal and paternal origin. The correct prediction of gender in all five male fetuses was an additional confirmation of trophoblast recovery. We conclude that trophoblasts can be effectively isolated from maternal blood in the first trimester, and by using polymorphic microsatellite markers to confirm sample purity, this method has potential future application in prenatal diagnosis.

[Clinical study of assessment of trisomy 21--precise risk evaluation in the first trimester of pregnancy]. / Eine klinische Studie zur Wertigkeit der Trisomie 21--Risikopräzisierung im ersten Trimester der Schwangerschaft.

BACKGROUND: In the past a non invasive risk analysis for detecting specific chromosomal aberrations was only possible from week 15 of pregnancy. In this paper the practicability of first trimester screening is analysed. MATERIAL AND METHODS: Blood samples were taken from 1000 pregnant women before a invasive prenatal diagnosis was performed. Total hCG, free beta-hCG and PAPP-A (pregnancy associated plasma protein A) was analysed. These data were combined with complete cytogenetic and ultrasonographic (CRL and nuchal translucency--NT) data. RESULTS: In more than 90% of cases the NT was below 3 mm. Here the rate of normal karyotypes was 97.8%. In 61 cases a abnormal karyotype was found. Here in the most cases we found an elevated NT. Also in the most cases of trisomy 21 and 18 and in triploidies a characteristic ratio of hCG/free beta-hCG and PAPP-A was discovered. Combining NT and biochemical analysis, 85% of trisomies 21 could be discovered as a risk group. CONCLUSIONS: This study demonstrates the possibilities of first trimester screening with a high detection rate for specific chromosomal aberrations. DISCUSSION: First trimester screening should only be performed in specialised centers because determination of NT and risk analysis needs extensive experience.

Paris-Trousseau syndrome platelets in a child with Jacobsen's syndrome.

The thrombocytopenia in an infant with clinical features of Jacobsen's syndrome characterized by multiple congenital anomalies, cardiac defects, psychomotor retardation, and deletion of chromosome 11 at 11q23.3 has been evaluated. Study of his platelets in the electron microscope revealed giant alpha granules in his cells identical in appearance to those reported in the family with Paris-Trousseau syndrome. As a result, the Paris-Trousseau syndrome appears to be a variant of the Jacobsen syndrome, and the thrombocytopenia observed in all cases of chromosome 11q23.3 deletion due to dysmegakaryopoieses. Giant alpha granules are frequently observed in normal platelets during long-term storage and may form in Jacobsen and Paris-Trousseau platelets during prolonged residence in the bone marrow.

Cytogenetic monitoring of men occupationally exposed to airborne pollutants.

A study of structural chromosomal aberration frequencies in peripheral blood lymphocytes was performed in a group of 20 professional drivers exposed to airborne pollutants and 20 matching controls. The subjects in the latter group were of the same sex (males) and of similar age as the exposed ones, and also had similar habits of smoking and alcohol. A statistically significant increase of chromosomal aberration was observed in the exposed subjects over the control group. An increasing trend of aberrations was observed with the duration of service (exposure) in the exposed individuals. This study clearly indicates the effect of occupational exposure to airborne pollutants.

Maternal serum Ca125 and Ca15-3 antigen levels in normal and pathological pregnancy.

OBJECTIVE: To evaluate the value of maternal serum CA125 and CA15-3 concentrations for discriminating pathological from normal pregnancies. METHODS: Serum samples from 120 women, in whom pregnancy outcome was pathological, i.e. spontaneous abortion, fetal death, intrauterine growth retardation, chromosomal and structural abnormalities, and (pre)eclampsia, were assessed for CA125 and CA15-3 and compared with levels found in 350 women with a normal pregnancy outcome matched for age and duration of pregnancy. RESULTS: Maternal CA125 serum values were significantly higher in the first and the third trimester of pregnancy (median 23.0 and 21.0 U/ml; p < 0.00001 and p < 0.001, respectively), compared to those in the second trimester (median 14.0 U/ml), but not significantly different from those obtained in pathological pregnancies. Maternal serum CA15-3 values were significantly higher during the third trimester (median 26.0 U/ml) compared to the first and second trimester of pregnancy (median 14.0 and 15.0 U/ml; p < 0.0001); CA15-3 serum levels in normal and pathological pregnancies showed no significant difference. CONCLUSION: Maternal serum levels of CA125 are higher during the first and third trimester of pregnancy. CA15-3 maternal serum levels are higher during the third trimester compared to the first and second trimester. Maternal CA125 and CA15-3 serum levels showed no relation with a pathological outcome of pregnancy.

Apoptosis in maternal peripheral blood during pregnancy.

OBJECTIVE: To investigate the mononuclear cell apoptosis rate during pregnancy. MATERIALS AND METHODS: Apoptosis was quantitated by EtBr staining in whole peripheral blood samples of 135 women in different gestational weeks and 85 nonpregnant women used as controls. Apoptosis was also qualitated by TUNEL assay. RESULTS: The apoptosis rate increased during pregnancy according to gestational age. In chromosomally abnormal fetuses apoptosis was 2.5-fold higher than that found in pregnancies with normal embryos matched for gestational age. FISH in TUNEL-positive cells using X, Y and 21 chromosome probes verified the fetal origin of part of the apoptotic population. CONCLUSION: Apoptosis is stimulated in maternal peripheral blood during pregnancy, possibly accounting partly for the presence of free fetal DNA in maternal serum. The increased apoptosis rate in pregnancies with chromosomally abnormal fetuses may have additional clinical importance.

Genetic analysis of fetal nucleated red blood cells from CVS washings.

Chorionic villus sampling (CVS) is an established invasive prenatal diagnostic method for the detection of fetal chromosome aberrations. In 1-2% the karyotype result of CVS is inconclusive and follow-up confirmation will be required. To avoid another invasive procedure we examined fetal nucleated red blood cells (NRBCs) from CVS washings for genetic analysis. We analysed the washings of 20 chorionic villi samples of male fetuses. Fetal NRBCs were immunostained by an antibody against embryonic haemoglobin (HbE). FISH was performed with probes specific for the X and Y chromosome and the nucleus was counterstained with DAPI. Cells positive for the antibody, as well as for DAPI, were collected and stored by a semi-automated microscope. An operator reviewed those cells for their FISH signals. In 19 out of 20 CVS washings we found nucleated cells positive for HbE together with XY FISH signals. In none of the washings HbE positive cells with two X signals were found. Our results indicate that anti-HbE is a very specific antibody for identifying fetal NRBCs. NRBCs from CVS washings can be used as an additional fetal tissue for first trimester prenatal diagnosis.

Identification of a group of AML/MDS patients with a relatively favorable prognosis who have chromosome 5 and/or 7 abnormalities.

BACKGROUND AND OBJECTIVE: Patients with AML, RAEB-t, or RAEB and abnormalities involving chromosomes 5 and/or 7 (-5, -7) generally, but not always, have poorer prognoses than patients with a normal karyotype. Our objective was to see whether the occasional relatively favorable outcome in -5/-7 patients is a random event or, rather, reflects true heterogeneity in -5/-7. DESIGN AND METHODS: We examined 3 factors known to be prognostic in AML for their prognostic significance in 400 -5/-7 patients treated at the M.D. Anderson Cancer Center from 1980-1998 for AML or MDS. The outcome of comparative interest was survival as assessed by log-rank test. RESULTS: There was evidence that outcome was better in -5/-7 patients with a simple (rather than complex) karyotype, with > 1 normal metaphase (rather than only metaphases containing -5/-7), and without an antecedent hematologic disorder. More importantly, the 10% of the patients with a simple karyotype, > 1 normal metaphase, and no antecedent hematologic disorder not only had a better outcome than the other -5/-7 patients but had essentially identical outcomes to the 669 AML/MDS patients with a normal karyotype treated at M.D. Anderson during the same period. INTERPRETATION AND CONCLUSIONS: The results indicate that the -5/-7 group should not a priori be regarded as having an unfavorable prognosis, and more generally suggest the need to refine prognosis within each of the cytogenetic subsets of AML.

New trends in prenatal screening for chromosomal abnormalities.

In the recent years, the scope of prenatal genetic diagnosis has expanded greatly with the development of a number of new methods, such as maternal serum screening and ultrasound screening for detection of fetal abnormalities. These methods have the advantage of providing earlier diagnosis in addition to being non-invasive and of less psychological traumas. Pre-implantation genetic diagnosis is another new growing field offering the genetic diagnosis prior to implantation. The most promising of all is the first trimester biochemical screening in conjunction with ultrasound nuchal translucency screening.

Cytogenetic damage in peripheral lymphocytes of mitochondrial disease patients.

Recent studies indicate an important role of endogenous oxidative stress in the onset and/or in the progression of mitochondrial encephalomyopathies. In particular, the increased production of radical species caused by altered mitochondrial functionality could affect both mitochondrial and nuclear DNA integrity. We performed the micronucleus assay coupled with fluorescence in situ hybridization (FISH) to detect chromosome damage in peripheral blood lymphocytes in a group of patients affected by different forms of mitochondrial encephalomyopathies. Moreover the comet assay has been carried out to detect primary and oxidative damage in the nuclear DNA. Our results show a significant presence of both DNA and chromosome damage in patients compared to a matched group of controls. A reduction in DNA alterations is also observed in patients after treatment with coenzyme-Q10.

Ultrasonographic markers for chromosomal abnormalities in women with negative nuchal translucency and second trimester maternal serum biochemistry.

OBJECTIVE: To analyze the value of second trimester ultrasound examination among those women whose fetuses were indicated to be at low risk of chromosomal anomalies on the basis of both first trimester nuchal translucency measurement and second trimester biochemical screening. METHODS: A retrospective study of 5500 pregnancies carried out at the fetal medicine unit, Royal Free Hospital. During a period of over 3 years 5500 pregnancies underwent a first trimester scan and nuchal translucency measurement which enabled the detection of 62% (20 of 32) of all chromosomal anomalies. From the remaining pregnancies that underwent second trimester biochemical screening, 3548 were considered negative (risk < 1:250; using maternal serum free beta human chorionic gonadotrophin and alpha fetoprotein). The ultrasound markers that were examined were: shortened femur length, echogenic bowel, pyelectasis, choroid plexus cysts and echogenic intracardiac foci. The likelihood ratios for chromosomal aneuploides for each of these markers were calculated. RESULTS: Of the 3548 screen negative pregnancies, 3541 (99.8%) had a normal karyotype. Seven (0.2%) fetuses had an abnormal karyotype including four (0.11%) with trisomy 21, one with trisomy 18 and two with 47XXY. Second trimester ultrasound markers were found in two of the five (40%) with severe chromosomal anomalies compared to 184 of 3541 (5.2%) with normal karyotypes. Detection of one or more ultrasound markers in a screen negative pregnancy increased the possibility of chromosomal aneuploidy and a negative ultrasound decreased the risk by a likelihood ratio of 0.6 (95% confidence interval, 0.3-1.3). The risk was considerably increased when two or more markers were detected and we would recommend karyotyping under these circumstances. CONCLUSION: This preliminary data indicates a possible role for abnormal ultrasound markers in assessing the risk of chromosomal abnormalities in patients considered to be at low risk by nuchal translucency and serum screening. However analysis of a much larger study group will have to be conducted to assess the significance of individual markers.

A putative susceptibility locus on chromosome 18 is not a major contributor to human selective IgA deficiency: evidence from meiotic mapping of 83 multiple-case families.

Previous reports of an association between constitutional chromosome 18 abnormalities and low levels of IgA suggested that this chromosome contains a susceptibility locus for selective IgA deficiency (IgAD), the most frequent Ig deficiency in humans. IgAD is genetically related to common variable immunodeficiency (CVID), characterized by a lack of additional isotypes. Our previous linkage analysis of 83 multiple-case IgAD/CVID families containing 449 informative pedigree members showed a significantly increased allele sharing in the chromosome region 6p21 consistent with allelic associations in family-based and case-control studies and provided the evidence for a predisposing locus, termed IGAD1, in the proximal part of the MHC. We have typed the same family material at 17 chromosome 18 marker loci with the average intermarker distance of 7 cM. A total of 7633 genotypes were analyzed in a nonparametric linkage analysis, but none of the marker loci exhibited a significantly increased allele sharing in affected family members. In addition, reverse painting and deletion mapping of a panel of constitutional chromosome 18 deletions/translocations showed the presence of IgA-deficient and IgA-proficient patients with the same abnormality and did not reveal a region commonly deleted. The linkage analysis of chromosome 8 and 21 regions involved in reciprocal translocations t(8;18) and t(18;21), which were identified in two patients lacking IgA, did not disclose a significant allele sharing. Although these results do not exclude the presence of a minor predisposing locus on this chromosome, such a putative locus would confer a population risk of developing IgAD/CVID much lower than IGAD1.

A role for maternal serum screening in detecting chromosomal abnormalities in fetuses with isolated choroid plexus cysts: a prospective multicentre study.

A prospective multicentre study was performed to identify patients with fetal choroid plexus cysts and examine the association between choroid plexus cysts and chromosome abnormalities in the context of variables such as maternal age, serum triple-screen results, race, other prenatally-identified fetal anomalies and cyst characteristics. A total of 18 437 scans were performed in 5 centres and 257 fetuses were identified with choroid plexus cysts. Outcome was available on 250 patients, and of these, chromosomal abnormalities were detected in a total of 13 (5.2 per cent) fetuses. 26 patients in the group had additional ultrasound abnormalities, and 8 of these had fetal chromosome abnormalities. Among the 224 patients with isolated choroid plexus cysts, 5 (2.2 per cent) were found to have chromosomal abnormalities. All cases with identified chromosomal abnormalities were associated with an additional risk factor, such as other ultrasound findings, advanced maternal age or abnormal maternal serum triple-screen results.

[Maternal blood fetal cells: new noninvasive approach in prenatal diagnosis of hereditary diseases]. / Kletki ploda v krovi materi: novyi neinvazivnyi podkhod v prenatal'noi diagnostike nasledstvennykh boleznei.

A new noninvasive approach to prenatal diagnosis of hereditary diseases is being actively developed, which is based on the use of different fetal cells contained in pregnant females. Due to the fact that the native concentration of fetal cells is extremely low, their isolation requires the application of different know-how enrichment and sorting techniques. Either the FISH method with chromosome-specific probes or PCR is used to examine the cell fraction isolated, which detects fetal sex, Mendelian disorders such as beta-globin mutations. Promising results in the prenatal diagnosis of chromosomal aneuploidies were achieved in isolating and examining fetal erythroblasts. The results of numerous studies on the optimization of a protocol for isolating and reliably examining fetal cells from the blood of pregnant females allow the new noninvasive approach to the prenatal diagnosis of hereditary diseases to be considered to be highly promising.

[Maternal serum screening for congenital abnormalities and Down syndrome in Sønderjylland County. Eight years of experience]. / Maternel serumscreening for medfødte misdannelser og Downs syndrome i Sønderjyllands Amt. Otte års erfaringer.

From January 1991 to December 1998 second-trimester maternal serum screening (Doubletest and Tripletest) for malformations and Down syndrome has been offered to pregnant women younger than 35 years of age living in Sønderjyllands county, Denmark. Follow-up of all cases of chromosome abnormalities and severe foetal malformations identified pre- or postnatally has been carried out. A total of 17,023 women were screened. Sixty-eight percent (17/25) of Down Syndrome pregnancies were detected. Three percent of the screened women were offered an amniocentesis due to a calculated risk of DS greater than 1:400 at birth. The positive predictive value was 1:30. For the three-year period 1996-1998 (Tripletest) the results were more promising: 91% (10/11) were detected, 3.9% were offered an amniocentesis, the positive predictive value was 1:21. In the eight-year period 80% (8/10) of the spina bifida cases were detected, all the cases (6/6) of anencephaly and 75% (6/8) of abdominal wall defects. One point six percent of the screened women were offered an amniocentesis due to high risk of a neural tube defect. The results confirm that second trimester maternal serum screening is a reliable method for determining the risk of severe foetal malformations and Down syndrome.

Comparison of comparative genomic hybridization with conventional karyotype and classical fluorescence in situ hybridization for prenatal and postnatal diagnosis of unbalanced chromosome abnormalities.

The comparative genomic hybridization (CGH) technique was initially used for detection of chromosomal imbalances in tumor cells. CGH can also be used as a supplementary method to karyotypic analysis in clinical cytogenetic cases. In order to evaluate CGH usefulness in prenatal and postnatal analysis of whole chromosome and segmental aneusomies, we investigated 13 clinical samples from blood, cultured chorionic villi, cultured amniotic fluids and uncultured amniotic fluids. These specimens, initially analyzed by conventional cytogenetics, included 5p monosomy, 9p duplication, add 6p, unbalanced translocation between chromosomes 5 and 10, mosaic tetrasomy 12p (50%), unbalanced (X;X) translocation and Prader-Willi deletion (15q11-13). In addition, six numerical chromosome aberrations (tetrasomy X, trisomies 13, 18, 21 and monosomy X) were analysed. All the chromosomal abnormalities, except the Prader-Willi deletion, were correctly detected by CGH. Here, we have demonstrated that the CGH technique is an alternative to classical fluorescence in situ hybridization using specific probes for detection of the unbalanced chromosomal aberrations in prenatal and postnatal diagnosis and could be used for rapid prenatal screening for unbalanced aberrations.

[The biochemical marker dynamics of the maternal serum in different chromosomal disorders of the fetus]. / Dinamika biokhimicheskikh markerov materinskoi syvorotochki pri razlichnykh khromosomnykh narusheniiakh u ploda.

The reasons for false-positive results of Down syndrome screening have been analysed. It has been found that the family pericentric inversions of chromosome 9 in fetus are accompanied by AFP and HCG changes equal to Down syndrome pregnancies. The average marker's levels in cases of per inv (9) were: AFp-0.51 MoM, HCG-3.71 MoM. The dynamics of markers in amniotic fluid has been studied. Clinical significance of per inv (9) in medicogenetic consultation were discussed.

Identificación de una nueva anomalía citogenética en el síndrome de duplicación 3q / Identification of a new cytogenetic rearrangement in the duplication 3q syndrome

Se presenta el caso de un paciente masculino con retraso psicomotor y características fenotípicas del síndrome dup (3q). El estudio citogenético reveló un rearreglo cromosómico de novo consistente en una inserción invertida de la región duplicada que resultó en un cariotipo 46,XY, der (3) (pter - q13.3::q27 - q26.1::q13.3 - qter). Esta aberración cromosómica no habria sido descrita previamente en este síndrome