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P Miny

Publications and source records attributed to P Miny.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Prenatal chromosome findings in sonographically conspicuous fetuses].

A retrospective evaluation of 463 prenatal chromosome analyses in a total of 375 patients with suspicious ultrasound findings, revealed a high rate of severe chromosomal abnormalities (16%). The highest risk for an abnormal karyotype was found after sonographic detection of hygroma colli. Abnormal chromosome counts were also frequently found in fetuses with omphaloceles, duodenal atresia and hydrops fetalis, as well as in presence of intrauterine growth retardation and/or anomalies of the amniotic fluid volume. The anomalies mentioned above are, therefore, an urgent indication for a prenatal chromosome analysis. The technical improvements of ultrasound machines and growing experience of operators will lead to an increasing importance of sonography as a method for the identification of pregnancies, that are at high risk for chromosomal abnormalities.

Adolescent↗
PubMed1991

[Prenatal diagnosis with chorionic villi and placenta puncture biopsy in the 1st to 3d trimester of pregnancy: diagnostic value of chromosome studies].

Chorionic villus sampling and placental biopsies became established diagnostic alternatives to amniocentesis worldwide during the 80's. Safety and accuracy are the most important criteria for the evaluation of these newer techniques as compared to amniocentesis. We report on our experience with more than 3400 chromosome analyses between 1985 and 1990 from first to third trimester of pregnancy in a single centre. Most obvious is the higher frequency of mosaicism, which is often, but not always confined to the placenta. Mosaicism accounts for the overwhelming majority of all discrepant (so-called false negative or false positive) cytogenetic findings. The most important prerequisites for diagnostic accuracy of chromosome analyses are meticulous separation of villi immediately after the sampling procedure as well as simultaneous use of direct preparation and cell culture. If mosaicism is not taken as sound evidence for foetal aneuploidy, the accuracy of cytogenetic diagnoses after chorionic villus sampling and placental biopsies is in the same range as the one after amniocentesis.

Adult↗
PubMed1990

First trimester maternal serum alpha-fetoprotein screening for Down syndrome and other aneuploidies.

Low maternal serum AFP (MSAFP) values in the first trimester of pregnancy have been associated with an increased risk for chromosome disorders. In our own first trimester chorionic villus sampling (CVS) series, MSAFP determinations were carried out in 1,448 singleton pregnancies. Aneuploidies were detected in 26 of these. The pre-CVS MSAFP values in these pregnancies were compared to those in pregnancies with normal outcome. Statistical analysis did not show a diagnostically useful correlation between low first trimester MSAFP values and aneuploidy in our cohort.

Aneuploidy↗
PubMed1990

'Late CVS' international registry compilation of data from 24 centres.

Data on 2058 late CVS cases, i.e., placental biopsies after 12 completed weeks of pregnancy, were collected from 24 centres. Two major groups of indications with or without ultrasound findings suspicious of fetal chromosomal abnormalities can be differentiated. In the first group, the rates of cytogenetic anomalies (21 per cent) and fetal losses (10 per cent) are high. The respective figures for the low-risk group are 6 per cent for chromosome anomalies and 2 per cent for total fetal losses. To evaluate this rapidly spreading new method further, more data are required and will be collected by the CVS registry based in Philadelphia, U.S.A.

Chorionic Villi Sampling↗
PubMed1990

Molecular basis of beta-thalassemia in Turkey: detection of rare mutations by direct sequencing.

Using restriction endonuclease analysis, oligonucleotide hybridization, and direct sequencing of amplified genomic DNA, we characterized 11 different mutations in the DNA of 26 patients from Turkey homozygous for beta-thalassemia. We found that mutations IVS-1 nt110, IVS-1 nt6, and the frameshift at codon 8 were the most frequent. By direct sequencing we characterized two very rare mutations not previously reported in the Turkish population: a frameshift +1 at codons 9/10 and a nonsense mutation at codon 15.

DNA↗
PubMed1990

Benefits of placental biopsies for rapid karyotyping in the second and third trimesters (late chorionic villus sampling) in high-risk pregnancies.

In a total of 301 placental biopsies in the second and third trimesters, 225 were performed because of suspicious ultrasonographic findings. In this group there was a high rate of aneuploidies (20%). As opposed to the alternative methods for rapid karyotyping, placental biopsies can easily be performed even in pregnancies with abnormal amounts of amniotic fluid. Oligohydramnios and polyhydramnios were key ultrasonographic findings in 38% of cases and were found to be associated with 22% of abnormal chromosomal findings. Suggestive ultrasonographic findings seem to justify the exclusive use of direct preparation.

Amniotic Fluid↗
PubMed1990

Ratio of fetal to maternal DNA is less than 1 in 5000 at different gestational ages in maternal blood.

Using Southern hybridization with the DNA probe pY3.4, we were not able to detect fetal DNA in blood of 36 pregnant women carrying male fetuses. Gestational ages ranged from 8-40 weeks of pregnancy. Using the same DNA probe, we were able to detect the male-specific signal in experimental dilution series down to 1/5000 on autoradiograms. We conclude that the ratio of fetal DNA in maternal circulation, in contrast to previous estimations, must be lower than 1/5000.

Autoradiography↗
PubMed1990

Transabdominal placental biopsy in the second and third trimesters of pregnancy: what is the risk of maternal contamination in DNA diagnosis?

We investigated the risk of maternal contamination in antenatal DNA diagnosis after second- and third-trimester transabdominal placental biopsy. For this purpose, we compared the restriction fragment length polymorphism (RFLP) patterns of 11 chorionic villus DNA samples after late chorionic villus sampling (CVS) with those of the corresponding maternal DNA. Ten of 11 aspirated tissue samples were not separated from maternal contamination before DNA extraction. All 11 mother-embryo pairs were informative for analysis of maternal contamination, ie, the mother showed one RFLP allele not present in the embryo. In none of the 11 cases did the fetal DNA show maternal contamination after molecular hybridization, although ten samples were contaminated with maternal tissue macroscopically and microscopically. Despite some maternal tissue admixture, the risk of contamination seems to be lower in the second- and third-trimester CVS than in first-trimester CVS, based on previous reports and our own experiences. This is most likely due to the anatomically closer contact of villi and decidua in the first trimester of pregnancy.

Alleles↗
PubMed1989

Validity of cytogenetic analyses from trophoblast tissue throughout gestation.

Cytogenetic findings in the Münster Chorionic Villi Sampling (CVS) program are presented after 1,184 first trimester transcervical samplings and 131 second and third trimester placentacenteses. In the first trimester series the abnormality rate is low (2.4%) in patients with only an age-dependent aneuploidy risk. In this group terminations were performed in only 1.6% because of aneuploidy. True mosaicism was found more frequently after CVS, and the risk of maternal cell contamination seems higher as compared to amniocentesis. There are no obvious differences in the overall rate of diagnostic errors after both procedures, when metaphases after direct preparation and chorionic cell cultures are analysed and doubtful findings such as mosaicism are adequately followed up by amniocentesis. The cytogenetic techniques also offer a very rapid approach to karyotyping in the second and third trimester. We found a high rate of aneuploidy (15%) when placentacentesis was performed after sonographic diagnosis of fetal abnormalities. We conclude that cytogenetic analysis from trophoblast tissue is an accurate diagnostic tool applicable from first to third trimester of pregnancy.

Amniocentesis↗
PubMed1989

First-trimester diagnosis of Menkes disease: intermediate copper values in chorionic villi from three affected male fetuses.

Chorionic villus samples with copper contents of 1.91, 4.2, 5.6, and 6.3 ng/mg were observed in four cases with male karyotypes. These values were outside the range for unaffected males (0.30-0.85 ng/mg), and three of them were outside the control range (0.20-2.39 ng/mg). But these three values were below the values previously observed for affected Menkes fetuses (12.0-24.8 ng/mg). Follow-up by 64Cu uptake studies on the amniotic fluid cells was performed in three of these cases. A combination of 64Cu uptake and chase experiments on the amniotic fluid cells showed more convincingly than 64Cu uptake per se the direct copper values of 4.2 and 5.6 ng/mg to correspond to affected fetuses. Amniotic fluid cells from the male fetus with the CV copper value of 1.9 ng/mg showed normal results. The CV copper value of 6.3 ng/mg was considered pathognomonic for Menkes disease. The pregnancy was terminated, and the diagnosis was confirmed on fetal fibroblasts. Maternal deciduum prepared from the placentae showed in one of the cases with an affected fetus copper values ranging from 1.5 to 5.7 ng/mg. In six additional diagnostic cases, the copper content was determined in both CV samples and maternal deciduum. In three of these cases with normal CV sample copper, maternal decidua values of 4.85-7.8 ng/mg copper were observed. These results show that maternal deciduum contamination of a CV sample could cause a false-positive diagnosis.

Amniotic Fluid↗
PubMed1988

Rapid karyotyping for prenatal diagnosis in the second and third trimesters of pregnancy.

Direct chromosome preparations were performed on placental villi obtained by ultrasound-guided needle aspiration between 18 and 37 weeks of pregnancy in 53 patients. The sampling yielded a sufficient amount of tissue with a maximum of two, and in most cases one, insertions. Placental biopsy is easily performed in cases of severe oligohydrammnios, where fetal blood sampling is usually more difficult. Direct karyotyping of placental villi is faster than chromosome analysis from fetal blood or application of the pipette method on amniotic fluid cells, and currently represents the most rapid approach to prenatal diagnosis of chromosomal abnormalities from the first to the third trimester of pregnancy.

Biopsy, Needle↗