Prenatal and postnatal genetic testing toward personalized care: The non-invasive perinatal testing.

This article investigates how non-invasive prenatal testing and the incorporation of genomic sequencing into newborn screening postnatally are transforming perinatal care. They improve the accuracy of prenatal and neonatal screening, allowing for early interventions and personalized therapies. Non-invasive prenatal testing before birth and saliva-sample-based newborn genomic sequencing after birth can be collectively referred to as non-invasive perinatal testing. Non-invasive prenatal testing is particularly useful for aneuploidy, whereas performance markers worsen as DNA abnormalities shrink in size. Screening for clinically actionable diseases in childhood would be crucial to personalized medical therapy, as the postnatal period remains appropriate for screening for the great majority of monogenic disorders. While genomic data can help diagnose uncommon diseases, challenges like ethics and equity necessitate joint approaches for appropriate integration in this revolutionary journey toward personalized care.

Predictive biomarkers of platinum and taxane resistance using the transcriptomic data of 1816 ovarian cancer patients.

OBJECTIVE: The first-line chemotherapy for ovarian cancer is based on a combination of platinum and taxane. To date, no reliable predictive biomarker has been recognized that is capable of identifying patients with pre-existing resistance to these agents. Here, we have established an integrated database and identified the most significant biomarker candidates for chemotherapy resistance in serous ovarian cancer. METHODS: Gene arrays were collected from the GEO and TCGA repositories. Treatment response was defined based on pathological response or duration of relapse-free survival. The responder and nonresponder cohorts were compared using the Mann-Whitney and receiver operating characteristic tests. An independent validation set was established to investigate the correlation between chemotherapy response for the top 8 genes. Statistical significance was set at p < 0.05. RESULTS: The entire database included 1816 tumor samples from 12 independent datasets. From analyzing all the genes for platinum + taxane response, we identified the eight strongest genes correlated to chemotherapy resistance: AKIP1 (p = 1.60E-08, AUC = 0.728), MARVELD1 (p = 2.70E-07, AUC = 0.712), AKIRIN2 (p = 2.60E-07, AUC = 0.704), CFL1 (p = 8.10E-08, AUC = 0.694), SERBP1 (p = 8.10E-07, AUC = 0.684), PDXK (p = 1.30E-04, AUC = 0.634), TFE3 (p = 7.90E-05, AUC = 0.631) and NCOR2 (p = 1.90E-03, AUC = 0.611). Of these, the independent validation confirmed TFE3 (p = 0.012, AUC = 0.718), NCOR2 (p = 0.048, AUC = 0.671), PDXK (p = 0.019, AUC = 0.702), AKIP1 (p = 0.002, AUC = 0.773), MARVELD1 (p = 0.044, AUC = 0.675) and AKIRIN2 (p = 0.042, AUC = 0.676). An online interface was set up to enable future validation and ranking of new biomarker candidates in an automated manner (www.rocplot.org/ovar). CONCLUSIONS: We compiled a large integrated database with available treatment and response information and used this to uncover new biomarkers of chemotherapy response in serous ovarian cancer.

[Longer oral contraception history as a possible preventive factor against fetal trisomy 21 in advanced maternal age pregnancies]. / A terhességet megelozoen alkalmazott hosszabb távú orális fogamzásgátlás mint a magzati 21-es triszómia lehetséges kockázatcsökkento tényezoje idos anyai életkorban vállalt terhességben.

Down syndrome is the most common autosomal chromosomal abnormality. According to the classical interpretation, it is the result of meiotic nondisjunction. Its occurrence is more common in advanced maternal age. Despite intensive research, pathophysiology of this genetic disorder is not fully understood. According to recent studies, a different kind of mechanism may be found in the background of trisomy 21 than was previously considered. Based on the ovarian mosaicism model, the cause of trisomy 21 (or any common trisomy) is a segregation error of a chromosome in premeiotic mitosis. The cell entering meiosis will be an oocyte with preexisting trisomy, where its (so-called "secondary") nondisjunction is essential. Maturation of the trisomic oocytes appears to fall behind the disomic oocytes, resulting in their relative accumulation in the ovaries as time progresses. The ratio of trisomic/disomic cells becomes less favorable in maternal maturity. If ovulation is inhibited - although the number of oocytes will continue to decline due to apoptosis - it can be assumed that the trisomic/disomic oocyte ratio remains more favorable with the progression of age. In our summary report, presenting and updating our previous data, we would like to propose that - according to ovarian mosaicism model - long-term oral contraception in the anamnesis may be beneficial in pregnancies with advanced maternal age. Orv Hetil. 2018; 159(28): 1146-1152.

[Rare case of a pregnancy in a woman with paroxysmal nocturnal hemoglobinuria. Case report]. / Paroxysmalis nocturnalis haemoglobinuriával szövodött várandósság ritka esete.

Paroxysmal nocturnal hemoglobinuria is a rare hematological disease. It is associated with increased maternal and fetal complications to such an extent that pregnancy has been considered relatively contraindicated in woman with paroxysmal nocturnal haemoglobinuria. Recently, eculizumab, a monoclonal antibody, has been shown to decrease complications during pregnancies. The highest risk is thromboembolic complication and, therefore, anticoagulant is a standard therapy during pregnancy. In the presented case, a 29-year-old woman with a 5-year history of paroxysmal nocturnal haemoglobinuria had a pregnancy. It was her first pregnancy and was complicated by a sinus thrombosis at the 11th gestational week. After the introduction of eculizumab treatment, the remaining period of pregnancy and delivery were uncomplicated. There are only a few cases in the literature about pregnancy in woman with paroxysmal nocturnal hemoglobinuria who are treated with eculizumab. This monoclonal antibody seems to be safe and it likely prevents many of the complications otherwise observed.

[Next generation sequencing and its applications in non-invasive prenatal testing of aneuploidies]. / Új generációs szekvenálás és használata az aneuploidiák nem invazív praenatalis vizsgálatában.

The development of the new generation sequencing techniques brought a new era in the field of DNA sequencing, that also revolutionized the prenatal screening for aneuploidy. In order to provide a more complete view, the authors describe some first generation methods as well as the theoretical and technical background of the next generation methods. In the second part of this review, the authors focuse on non-invasive prenatal testing, which is a fetal cell-free DNA based method requiring advanced sequencing procedures. After discussing the theoretical and technical background, the authors review current application and utility of non-invasive prenatal testing. They conclude that non-invasive prenatal testing is the most effective screening test in high risk pregnancies and its efficiency can be justified in studies involving low risk pregnancies as well.

Lower risk for Down syndrome associated with longer oral contraceptive use: a case-control study of women of advanced maternal age presenting for prenatal diagnosis.

BACKGROUND: Maternal trisomy 21 ovarian mosaicism might provide the major causative factor for fetal Down syndrome. The small proportion of trisomy 21 oocytes thought to be retarded in their maturation in comparison to normal disomic ones, and the maternal age effect can be based on an accumulation of trisomy 21 oocytes in the ovarian reserve. By lowering the number of unnecessary ovulations, a greater portion of disomic oocytes might be saved. STUDY DESIGN: Between September 2009 and September 2011, we performed genetic amniocentesis for fetal chromosomal analysis in 5222 pregnancies. We detected 119 structural or numerical chromosomal abnormalities. We collected data from 37 cases who were in advanced maternal age and where fetal trisomy 21, 18 or 13 was confirmed. We had 92 control patients. Detailed information was taken from those factors that influence the number of ovulations in reproductive life. RESULTS: From the factors checked, patients with a trisomic fetus had a shorter overall mean length of oral contraceptive pill use before the trisomic pregnancy (3.4 vs. 6.0 years, p<.0014), and the estimated number of mean ovulations was higher (274.6 vs. 224, p<.0003). CONCLUSION: We found that a history of longer oral contraceptive pill use and fewer ovulatory cycles were associated with fewer common trisomies of the fetus. Additional research is needed to rule out potential confounding factors, but our results are consistent with the maternal ovarian mosaicism causal model.

[Cell-free nucleic acid-based non-invasive prenatal diagnosis of fetal aneuploidies]. / Magzati aneuploidiák szabadnukleinsav-alapú, nem invazív diagnosztikája.

Prenatal detection of fetal aneuploidies is one of the main goals of the prenatal diagnostic approach. As a benefit of the development of advanced ultrasound equipment and advances in molecular biology in the last decade, there is a significant progress in screening methods for fetal aneuploidies, although invasive methods remain the gold standard for aneuploidy detection. Non-invasive prenatal diagnosis has substantial medical impact as it targets the development of safer and more effective methods to avoid the risk of fetal loss associated with currently used invasive methods. Identification of fetal-specific messenger ribonucleic acids, digital polymerase chain reaction and next-generation sequencing give the real chance for non-invasive prenatal diagnosis of fetal aneuploidies. Although all these methods have both advantages and limitations, some of them are moving closer to clinical implementation. In this review the authors highlight the most recent advances in methods for non-invasive prenatal diagnosis of aneuploidies.

Comparison of prevalence of toxoplasma and cytomegalovirus infection in cases with fetal ultrasound markers in the second trimester of pregnancy.

OBJECTIVES: To evaluate the prevalence of toxoplasma and cytomegalovirus (CMV) infections in cases of ultrasound anomalies detected in the second trimester of pregnancy. METHODS: Serological examinations for toxoplasma and CMV infection were carried out in 655 cases with sonographic findings suggestive of fetal infection, 612 cases with single ultrasound markers and 43 cases with two or more markers. RESULTS: In cases of single ultrasound markers, serological examination diagnosed recent toxoplasma infection in 107/612 cases (17.5%) and recent CMV infection in 75 cases (12.3%). Recent toxoplasma infection accounted for 13.8% (52/377) of the intracranial sonographic findings and 23.9% (45/188) of the abdominal findings, whereas recent CMV infections accounted for 12.2 (46/377) and 11.7% (22/188), respectively. Recent CMV infection with sonographic manifestations had higher rates of intracranial than intra-abdominal sonographic findings (46/75 or 61% vs 22/75 or 29%), whereas recent toxoplasma infection with sonographic manifestations had similar rates of intracranial (52/107 or 49%) and intra-abdominal (45/107 or 42%) findings. In cases of two or more ultrasound markers, serological examination diagnosed recent toxoplasma infection in 12/43 cases (27.9%) and recent CMV infection in 10/43 cases (23.3%). CONCLUSIONS: Ultrasound findings suspicious for toxoplasma and CMV infection are not pathognomonic for either pathologic entity.

Circulating levels of the anti-angiogenic thrombospondin 2 are elevated in pre-eclampsia.

An imbalance of maternal circulating pro- and anti-angiogenic factors may play a role in the pathogenesis of pre-eclampsia. Thrombospondin 2 (TSP-2) is a protein expressed mainly by activated endothelial cells, which acts as a potent anti-angiogenic agent. Our aim was to determine whether serum TSP-2 levels are altered in pre-eclampsia. We enrolled 35 pre-eclamptic patients and 35 healthy pregnant women in the study. Thrombospondin 2 levels were determined by enzyme-linked immunosorbent assay, while soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) concentrations were determined by electrochemiluminescence immunoassay. In patients with PE, we demonstrated 1.7-fold higher TSP-2 [13.2 (9.4-18.1) vs. 7.9 (7.2-11.2) ng/ml, p<0.001], 3.8-fold higher sFlt-1 and 4.3-fold lower PlGF levels compared with the control group. There were no associations between TSP-2 and sFlt-1 or PlGF concentrations. We suggest that circulating TSP-2 levels may contribute to the pathogenesis of PE via its anti-angiogenic properties, but in a distinct way from sFlt-1 and PlGF.

[Microchimerism, as an inheritance from pregnancy]. / Microchimaerismus mint terhességi örökség.

During pregnancy, due to the bidirectional traffic through the placenta, chimera cells or DNA gets into the mother's and her fetus' body. This is the phenomenon of fetal and maternal microchimerism. These cells, even decades after the birth, can be detected in the host. Despite the fact that a lot of research-team deals with this phenomenon, the importance of microchimerism in health and diseases remains little known. In this article, we aimed to give an overview of the current state of science about this topic. The possible role of microchimerism studied mostly in the pathogenesis of autoimmune processes, non-autoimmune diseases and tumors, or even in the regression of them; it can be as well as a possible component of transplant immunology. The phenomenon of microchimerism could mean important opportunity in the non-invasive prenatal diagnosis, cutting off the currently associated risk of abortion. Due to the constantly developing cell identification- and enrichment procedures, it is expected to be revealed in more and more processes of the human body, that microchimera cells and DNA, as an inheritance of pregnancy, play a role in them.

Prenatal diagnosis and fetopathological investigation of dorsolumbosacral agenesis.

Sacral and lumbosacral spine agenesis, as characteristic signs of a rare congenital malformation--caudal regression syndrome--has been well described. However, dorsolumbosacral agenesis involving the lower thoracic, lumbar, and sacral vertebrae has rarely been reported, and prenatal diagnosis of this severe form has not been published yet. A 37-year-old woman (gravida 2, para 0) who had diabetes mellitus asked for termination of her pregnancy, because second-trimester ultrasound screening showed dorsolumbosacral agenesis of the fetus. Fetopathological examination confirmed the prenatal diagnosis and showed that the lower seven thoracic and all lumbosacral segments were absent. The noticed small "bony" structure in the lumbar region supported the idea that caudal regression syndrome can be regarded as a "multisegmental" spinal dysgenesis that involves the caudal part of the spine. Reliable prenatal diagnosis of dorsolumbosacral agenesis is possible by second-trimester ultrasound. The prenatal sonologist should always try to look for and assess abnormalities during examinations. Emphasis should be placed especially on those types that have a higher risk of being present in the fetus because of the known risk factors in the particular pregnancy. Fetopathological examination emphasized the suggestion that segmental spinal dysgenesis and caudal regression syndrome may represent two faces of a single spectrum of segmental malformations of the spine and spinal cord.

[Quantity and quality of obstetrical care in Baross Street Department of Obstetrics and Gynecology between 1990 and 2006]. / A szülészeti ellátás mennyiségi és minôségi mutatói a Baross utcai Nôi Klinikán 1990 és 2006 között.

AIM AND METHODS: Authors report data from 48,794 deliveries in Semmelweis University, I. Department of Obstetrics and Gynecology, from January 1, 1990 to December 31, 2006. Data were analyzed based on their computer database, showing complexity of obstetrics, genetic counseling and neonatology. RESULTS: In the last 17 years the delivery number is increasing, from 2,299 in 1990 to 3,861 in 2006. Early neonatal mortality rate is decreasing (22 infant deaths per 1,000 live births in 1990 compared with 6 in 2006). If we do not take those < or =1,000 grams, intrauterine death outside the institute, and induction of labour because of malformation, perinatal mortality is very low, below 6/1,000 deliveries in the last 7 years, 2.8 in 2004, 1.8-1.9 in 2005 and 2006. Neonatal and infant mortality is also decreasing. There is an increase in the frequency of cesarean sections, 15-20% in 1990-1991, and approximately 35% in the last years. Main indications are previous cesarean section, threatened fetal hypoxia, dystocia, cephalopelvic disproportion, twin pregnancy, hypertension/preeclampsia/HELLP syndrome, breech presentation. CONCLUSIONS: Because of the progressive system in obstetrics care in Hungary, in this leading institute approximately one fifth of the deliveries are preterm, furthermore they also have numerous severe pathological cases, though there are favorable changes in perinatal statistics in the last 17 years, showing the continuous improvement in obstetrical and neonatological care.

[Non invasive detection of fetal Rh using real-time PCR method]. / Noninvazív magzati Rh-meghatározás real-time PCR-módszerrel.

INTRODUCTION: In the last ten years the detection of fetal origin cells and cell free fetal DNA in maternal circulation opened new horizons in non-invasive prenatal diagnosis. The diagnostic possibilities are based on the differences between the maternal and fetal origin DNA. One of the differences could be the Rh blood group and the genetical background. The Rh incompatibility is the most frequent blood group incompatibilities in the clinical practice, which can cause fetal anemia, hydrops and even fetal death. AIMS: The aim of this study was to detect the fetal DNA in maternal circulation, to determine the Rh status of the fetus, and to compare the reliability of the method with the data found in other studies. METHODS: Blood samples and amnionic fluid samples were collected from 30 pregnant women, with Rh negative status, between 11-22 week of gestation presented for genetic amniocentesis at the 1st. Department of Obstetrics and Gynecology, Semmelweis University. After DNA isolation real-time PCR was performed in order to detect the exon 7 of the RhD gene located on the first chromosome (1p36.11.). RESULTS: In 24 cases the PCR reaction gave same result in case of the DNA isolated from plasma and amniotic fluid, but in six cases there was no PCR product of plasma samples and the product was detectable in amniotic fluid samples. The exon 7 was detectable in 25 cases, and there was no product in 5 cases. CONCLUSIONS: The real-time PCR method seems to be an easy and reliable method to determine the fetal Rh blood group. The sensitivity and specificity of the method in this study is in concordance with international data. The use of more than one probe could increase the sensitivity of the method.

Detection of DeltaF508del using quantitative real-time PCR, comparison of the results obtained by fluorescent PCR.

OBJECTIVE: Cystic fibrosis (CF) is the most common autosomal recessive genetic disorder in the Caucasian population. The molecular diagnosis is difficult since there are about 1,000 mutations in the CF transmembrane regulator gene. The DeltaF508del is the cause of the CF in 64% of the cases in Hungary. Our aim was to compare two polymerase chain reaction (PCR)-based method for the detection of DeltaF508del. METHODS: One hundred and sixteen DNA samples isolated from different tissues (84 blood samples, 18 chorionic villus samples and 14 amniotic fluid samples) were involved in the study. Fluorescent PCR with DNA fragment analysis and quantitative real-time PCR with melting curve analysis were performed on the DNA samples for the detection of DeltaF508del. RESULTS: Sixty-five healthy normal samples, 43 heterozygous samples, 6 DeltaF508del homozygous samples and 2 DeltaF508C homozygous samples were detected by using quantitative real-time PCR combined with melting curve analysis. The fluorescent PCR method did not detect the DeltaF508C mutation and these two samples were diagnosed as normal healthy ones. CONCLUSIONS: The quantitative real-time PCR with melting curve analysis is a reliable and fast method for the detection of DeltaF508del. The results are ready in 1 h following the DNA isolation. The applied primer-probe set with melting curve analysis gives additional information for the presence of other mutations in the DeltaF508del region.

Use of routinely collected amniotic fluid for whole-genome expression analysis of polygenic disorders.

BACKGROUND: Neural tube defects related to polygenic disorders are the second most common birth defects in the world, but no molecular biologic tests are available to analyze the genes involved in the pathomechanism of these disorders. We explored the use of routinely collected amniotic fluid to characterize the differential gene expression profiles of polygenic disorders. METHODS: We used oligonucleotide microarrays to analyze amniotic fluid samples obtained from pregnant women carrying fetuses with neural tube defects diagnosed during ultrasound examination. The control samples were obtained from pregnant women who underwent routine genetic amniocentesis because of advanced maternal age (>35 years). We also investigated specific folate-related genes because maternal periconceptional folic acid supplementation has been found to have a protective effect with respect to neural tube defects. RESULTS: Fetal mRNA from amniocytes was successfully isolated, amplified, labeled, and hybridized to whole-genome transcript arrays. We detected differential gene expression profiles between cases and controls. Highlighted genes such as SLA, LST1, and BENE might be important in the development of neural tube defects. None of the specific folate-related genes were in the top 100 associated transcripts. CONCLUSIONS: This pilot study demonstrated that a routinely collected amount of amniotic fluid (as small as 6 mL) can provide sufficient RNA to successfully hybridize to expression arrays. Analysis of the differences in fetal gene expressions might help us decipher the complex genetic background of polygenic disorders.

[Detection of deltaF508 deletion causing cystic fibrosis, using quantitative real-time PCR]. / A cystis fibrosist okozó F508 deléció kimutatása kvantitatív real-time PCR-módszerrel.

INTRODUCTION: Cystic fibrosis is the most common autosomal recessive lethal genetic disorder in the Caucasian population. There are about 1400 mutation in the cystic fibrosis transmembrane regulator gene, which makes the molecular diagnosis difficult, while luckily in Hungary the cause is the deltaF508del in almost 60% of the cases. METHOD: The authors introduced the quantitative real-time PCR and melting curve analysis method for the detection of deltaF508del. They studied 94 samples (70 blood, 16 chorionic villi, 8 amniotic fluids). RESULTS: They found 52 healthy normal, 36 heterozygotic and 5 homozygotic samples and one deltaF508C homozygotic sample. DISCUSSION: The quantitative real-time PCR and melting curve analysis is a reliable and fast method for detection of deltaF508del. The results are available in one hour following the DNA isolation. The primer-probe set makes available the deltaF508Cdel detection too.

Detection of Toxoplasma gondii from amniotic fluid, a comparison of four different molecular biological methods.

BACKGROUND: The infection caused by the parasite Toxoplasma gondii (T. gondii) is often asymptomatic or has mild symptoms. The infection can cause serious problems in pregnant women who acquire the infection during gestation and their fetuses are congenitally infected. METHODS: We tested 64 amniotic fluid samples for the presence of T. gondii by using fluorescent PCR and DNA fragment analysis. Later we compared four different molecular biological methods for the detection of the presence of T. gondii on same frozen DNA samples. These methods are the conventional PCR, fluorescent PCR with DNA fragment analysis, quantitative real-time PCR with SYBRGreen I and with fluorescence energy transfer hybridization probe detection. We determined the detection limit of these methods. RESULTS: The conventional PCR and quantitative real-time PCR with SYBRGreen I detection have the detection limit of 1000 parasites, followed by fluorescent PCR with the detection limit of 10-100 parasites. The real-time PCR using fluorescence energy transfer hybridization probes can detect one parasite. This is the most sensitive and the fastest method. We detected 5 T. gondii positive samples with all methods from the studied 64 amniotic fluids. CONCLUSIONS: All studied molecular biological methods are suitable for the detection of congenital toxoplasmosis. The quantitative real-time PCR based methods are more sensitive, simple and easy to perform these are opening the avenue to find out the effect of the number of parasites on fetal abnormalities.

Isolation of epsilon-haemoglobin-chain positive fetal cells with micromanipulation for prenatal diagnosis.

OBJECTIVES: The isolation and analysis of fetal cells in maternal blood during pregnancy is under investigation as a means of noninvasive prenatal diagnosis. The aim of our study was to detect fetal gender from maternal peripherial blood samples during pregnancy with the detection and analysis of epsilon-haemoglobin-chain positive fetal nucleated red blood cells (NRBCs) collected by a micromanipulator. Here we report our first results. DESIGN AND METHODS: We obtained maternal blood from 14 singleton pregnancies. After a double density gradient separation, magnetic activated cell sorting was performed by positive selection for nucleated red blood cells with anti-CD71. With the help of this enrichment step, followed by immunophenotyping with an anti-haemoglobin-epsilon monoclonal antibody, the isolation of the epsilon haemoglobin chain positive cells with micromanipulation could be done. We performed single cell fluorescent PCR analysis of these cells; we used primers for the amelogenin gene to detect fetal gender. We compared our findings with the results of amniocentesis. RESULTS: Fetal gender was successfully determined in 11 out of 14 cases; among them, in 2 cases with Klinefelter syndrome (47,XXY). CONCLUSION: The results of our study suggest that micromanipulation and QF-PCR analysis of anti-haemoglobin-epsilon fluorescent antibody stained fetal cells from maternal blood can be useful in prenatal diagnosis to detect fetal gender and promising to be improved to detect chromosomal abnormalities.

[First attempts of detecting fetal cells in the maternal circulation]. / Elso lépéseink a magzati sejtek anyai keringésbol történo kimutatásában.

INTRODUCTION: In prenatal diagnosis there is great interest for noninvasive diagnostic methods. Authors report their first results in detecting fetal cells in the maternal circulation during pregnancy. OBJECTIVE: The aim of the study was to detect fetal gender from maternal peripheral blood samples during pregnancy. METHOD: Authors have analysed fetal nucleated red blood cells. In 12 cases after a double density Percoll gradient separation they labelled the surface antigens of the cells with anti-glycophorin-A and anti-CD45 fluorescent antibodies, did an intracellular staining of the epsilon haemoglobin chain, and analysed the cells with flow cytometry. The CD45 negative/glycophorin-A positive/epsilon-haemoglobin chain positive cells were considered as fetal cells. Having the results, in another 13 cases magnetic activated cell sorting with CD71 antibody were used as an enrichment step. Authors made an intracellular staining of the epsilon haemoglobin chain, the positive cells were isolated by micromanipulation, and analysed by single cell fluorescent polymerase chain reaction. Primers for the amelogenin gene were used to detect fetal gender. RESULTS: Only the Percoll enrichment step itself is not enough for using the samples for diagnostic molecular-biologic examinations, a following enrichment step is needed. For this the authors used magnetic activated cell sorting with CD71 antibody. With the help of this enrichment step, after the intracellular staining of the epsilon haemoglobin chain the direct micromanipulator isolation of the epsilon haemoglobin chain positive cells could be done. After analysing single cells by fluorescent polymerase chain reaction, in 8 out of the 11 comparable cases the results were similar to those, what was found during the genetic amniocentesis. In 2 cases from this 8, genetic amniocentesis proved Klinefelter syndrome, which they could also confirm with the examination of fetal cells in the maternal circulation. CONCLUSION: The results of the study suggest that the method described above can be useful in prenatal genetic diagnosis, and improving it could be useful to detect other genetic abnormalities (chromosomal abnormalities, single gene disorders) as well.