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1.
Nineteen pregnancies at risk for the Martin–Bell syndrome have been monitored during the second trimester for the presence of the fragile Xq27. Of the 19 potential carrier mothers, 14 showed the presence of the fragile X in their lymphocytes at a level of 4 per cent or above. As one was a twin pregnancy, fetal blood was obtained at fetoscopy from 20 fetuses and amniotic fluid obtained simultaneously from 19 of them. Of the 20 fetuses, 18 were males (including both of the twins) and two were females. Of these 18 males, seven were found to carry the fragile Xq27 in lymphocytes and subsequently six of the seven were terminated. The diagnosis was confirmed in five of the six terminated fetuses (the sixth case was a patient whose pregnancy was terminated abroad) and also in a full-term male baby. Five of the seven males without the marker X who came to term had their karyotypes confirmed post natally. Of the two female fetuses one was found to be a carrier of the fragile X and the other was not. Both babies had full-term deliveries and both had their karyotypes confirmed post natally. In some cases the diagnosis made in fetal lymphocytes was confirmed later in amniocytes.  相似文献   

2.
An apparently normal female infant was born after the prenatal diagnosis of fragile Xq27×28 present in about 4 per cent of amniocytes. The mildly retarded mother had been found in early pregnancy to be heterozygous for fragile X. The child, now 9 months old. showed about the same level of fragile X expression as her mother. Variations in the proportion of cells with fragile X appeared to be related to cell type and laboratory techniques. The infant's growth and development have been normal. Different techniques to induce or increase the expression of fragile X are discussed.  相似文献   

3.
The psychological reactions of 211 women undergoing prenatal diagnosis (PND) with amniocentesis (group A, n = 122) or chorionic villus biopsy (group V, n = 90) were exmained by questionnaires and interviews. The distress experienced while waiting for the test, during the test procedure, and while waiting for the result was reported by the women, both in questionnaires and in interviews. In the questionnaires, no difference between the two diagnostic methods was observed. In the interviews, however, the women undergoing amniocentesis appeared significantly more distressed by the procedure. In group A 97 per cent and in group V 100 per cent wished a method which, like chorionic villus biopsy, could be used in the first weeks of pregnancy. The risk of miscarriage was, as described in other studies, regarded as a serious threat by the pregnant women.  相似文献   

4.
We report the first prenatal diagnosis of an affected fetus with Chediak-Higashi syndrome (CHS). Diagnosis was accomplished via fetal blood sampling at 17 menstrual weeks and was confirmed after birth. Retrospective measurement of the largest acid phosphatase-positive lysosomes in cultured amniotic fluid cells and chorionic villus cells showed that in CHS these lysosomes are significantly larger than those in normal cells. This method may be used for prenatal diagnosis of CHS by amniocentesis and chorionic villus sampling (CVS).  相似文献   

5.
Amniocentesis and prenatal diagnosis were done for late maternal age and an abnormality consistent with Tetrasomy 21 (47,XX,+t(21;21)) was found in every cell examined of the initial amniotic fluid. Clinical examination revealed a fetus with many of the signs of Down Syndrome and pathological examination revealed gross abnormalities of the internal structures. Follow-up tissues showed mosaic Tetrasomy 21.  相似文献   

6.
Our experience with the prenatal detection of the Lesch-Nyhan syndrome (LNS; hypoxanthine-guanine phosphoribosyltransferase (HGPRT) deficiency) in three fetuses at risk is reported. Enzyme activities were measured in cultured amniocytes in two pregnancies, and in tissues and cultures obtained from chorionic villus sampling (CVS) in a third pregnancy. In all tissues the specific activities of HGPRT and adenine phosphoribosyltransferase (APRT) were determined and APRT/HGPRT ratios were calculated. In addition to the enzyme assays, the rate of purine synthesis de novo was assessed in the two amniocyte cultures, and the rate of [14C]hypoxanthine incorporation into nucleotides and sensitivity to azaguanine were measured in one of the amniocyte cultures. We report the diagnosis of normal fetuses by study of amniocytes in two pregnancies and of LNS using CVS in one pregnancy. In all three cases the diagnosis was confirmed.  相似文献   

7.
Early prenatal diagnosis of the fragile X was attempted in 44 pregnancies, including one twin pregnancy at risk of Martin-Bell (MB) syndrome. The sex ratio was 24M:21F. The fragile site was reproducibly demonstrated in cultured chorionic villus (CV) cells in eight male and five female fetuses. Six of the male and three of the female fetuses were terminated. Simultaneous RFLP analysis provided confirmative data with flanking DNA markers in 3 of 13 analysed cases. Recombination and/or non-informativeness at available distal and/or proximal loci were found in nine cases. In one male fetus, discordance between the haplotype and cyto-genetics (fragile-X-negative) suggested the presence of a normal male transmitter, a double meiotic cross-over within the region, or a false-negative cytogenetic diagnosis. However, discordance between prenatal and post-termination/postnatal cytogenetic findings was not observed in this series. The use of excess thymidine for induction of the fragile X in cultured CV cells provided in the majority of cases a safe and rapid method for cytogenetic diagnosis, with options for early induced termination in fragile-X-positive pregnancies, for simultaneous RFLP analysis, and for subsequent second-trimester analysis of fetal blood in complicated cases.  相似文献   

8.
Pure fetal blood, (uncontaminated with maternal blood), was obtained from two male fetuses at risk for X-linked mental retardation with fragile(X) at Xq27–28 by direct vision fetoscopy and fetal blood sampling. Both were shown to have this fragile site on the X chromosome while nine other fetal blood samples from pregnancies at risk for other X-linked diseases, or haemoglobinopathies did not show fragile sites at Xq27–28, and a blood sample from an abortus showed only 1 fragile site in 95 mitoses. Both pregnancies were terminated, cultures established from fetal tissues, and the diagnosis confirmed in each case. The problems of demonstrating the fragile site in tissues other than fetal blood in these pregnancies (such as amniotic fluid cells or fibroblasts from fetal tissues) are discussed.  相似文献   

9.
Prenatal diagnosis for Tay-Sachs disease was performed on 25 patients using chorionic villus sampling (CVS). Nineteen were diagnosed as normal, and six were affected. Normal villus extracts had both hexosaminidase (hex) A and B activity, as determined by Cellogel and polyacrylamide gel electrophoresis, while extracts from affected fetuses had only hex B activity. Compared to cultured amniotic fluid cells or fibroblasts, villi contained less hex A. Hex A levels in fresh villi and cultured trophoblasts were roughly comparable.  相似文献   

10.
Cytomegalovirus (CMV) is the most common cause of congenital infection. Recent studies show amniocentesis to be a 100 per cent sensitive and 100 per cent specific predictor of congenital infection, and recommend that it be offered in the at-risk pregnancy. However, these publications have focused on pregnancies at or beyond 22 weeks' gestation. Here, we report a case of maternal CMV hepatitis at 7–8 weeks' gestation, in which culture and polymerase chain reaction testing for CMV in amniotic fluid at 20 weeks' gestation were negative, but the infant had a positive CMV urine culture shortly after delivery. Implications for the prenatal diagnosis of CMV infection are discussed.  相似文献   

11.
Direct detection of the fragile X mutation by DNA analysis has greatly simplified prenatal diagnosis of this disease. However, women carrying a fragile X premutation may pass their expanded trinucleotide repeat to sons without expansion to a full mutation. Such sons are predicted to be intellectually normal. In this situation, the accuracy with which the fetal status can be inferred from analysis of chorionic villus sample (CVS) DNA is unclear. We describe such a case, in which it was felt necessary to proceed to fetal blood sampling despite technically unambiguous DNA results from the CVS. The lack of prospective data means that this dilemma may be expected to recur over the next few years when performing prenatal diagnosis on fragile X premutation carriers.  相似文献   

12.
We have performed prenatal diagnosis for glutaryl-CoA dehydrogenase (GDH) deficiency in 16 pregnancies at risk by measuring the enzyme activity in chorionic villus samples. In most cases, GDH activity was measured both in uncultured chorionic villus samples and in cultured chorionic cells. In 4 of the 16 cases, an affected fetus was predicted, while the remaining cases were found to be normal. In three of the four affected cases, GDH activity was measured in both uncultured and cultured chorionic cells and the correct diagnosis established by both measurements. In the fourth case, only cultured cells were investigated because the chorionic villus sample was too small for the direct assay. All four pregnancies predicted to be affected were interrupted and the diagnoses confirmed on the aborted material in three of the cases. In the fourth case, no material was available for investigation. Of the 12 pregnancies predicted to be unaffected, ten cases resulted in the birth of healthy unaffected babies while two pregnancies are still in progress.  相似文献   

13.
The prenatal diagnosis of cystinosis is currently based on the increased amount of free-cystine present in amniotic fluid cells. Amniocyte cultures must be grown for at least 2 weeks to obtain sufficient cells for such measurements. Thus, the diagnosis cannot be made until close to 20 weeks gestational age by this method. We report a case in which chorionic villi were used for direct cystine measurement resulting in the in utero diagnosis of cystinosis at 9 weeks gestational age. The diagnosis was confirmed by the study of cultured chorionic villus cells, and of the 10-week abortus.  相似文献   

14.
By means of chorion biopsy together with restriction endonuclease analysis of fetal DNA, first trimester diagnoses were successfully made in 33 fetuses at risk for Bart's hydrops fetalis. Seven pregnancies with Hb H or hydrops fetalis were therapeutically terminated before 4 months of gestation. Of the 26 pregnancies intended to continue, 18 have come to term with normal deliveries; one with threatened abortion was terminated at the end of the first trimester and, seven are progresssing normally.  相似文献   

15.
A case of the Hunter syndrome diagnosed prenatally using chorionic villi is presented. Chorion biopsy was performed in the 10th week of pregnancy. The sample was examined for karyotype and for iduronate sulfatase activity. The fetus was male and the enzyme activity reduced to 4 per cent of normal. Termination of pregnancy occurred at the 11th week.  相似文献   

16.
A fetus with an extra idic(X) (q27) was ascertained during prenatal diagnosis. The derived X and one normal X chromosome were late replicating. Due to lack of previous experience, genetic counselling presented obvious difficulties and the fetal phenotype could be only tentatively predicted.  相似文献   

17.
Chorionic villus sampling (CVS) has emerged as a first trimester alternative to amniocentesis for the prenatal detection of genetic disorders. We report our experience in 600 consecutive CVS procedures to better delineate the safety, efficacy and reliability of this new method of prenatal diagnosis. Adequate samples were obtained at the initial visit in 97 per cent of the cases, and successful cultures were established in 98.7 per cent of these patients. Chromosome abnormalities were detected in 5.9 per cent of those pregnancies tested because of advanced maternal age (≥ 35 years). A discrepancy between the villus karyotype and that of the fetus was found in 2.0 per cent of cases, and most commonly consisted of mosaicism in the villus sample for a chromosomal abnormality that was not found in fetal samples. The risk of spontaneous abortion following the procedure was 6.3 per cent. We conclude that chorionic villus sampling is an acceptably safe and reliable procedure, but further investigation is needed before it can become an established technique in prenatal diagnosis.  相似文献   

18.
The prenatal diagnosis of an 11q;22q translocation in a triplet pregnancy detected at the time of chorionic villus sampling (CVS) because of advanced maternal age is reported. Karyo-types obtained from two apparently different CV samples showed the balanced form of translocation, while the one obtained from a third empty sac showed the unbalanced form: 46, XX, −22, + der(22)t(11;22). Second-trimester amniocentesis confirmed the balanced translocation in one of the two viable fetuses and a normal karyotype in the other. The detected karyotypes derived from two different types of meiotic segregation, alternate and adjacent 1. To our knowledge, this is the first reported case of an unbalanced karyotype not due to a 3:1 meiotic segregation of this specific translocation.  相似文献   

19.
Three hundred and thirty-nine cases of multiple gestation underwent prenatal diagnosis by amniocentesis. The spontaneous abortion rate (to 28 weeks) in this group was 3.57 per cent compared with our singleton abortion rate of 0.60 per cent. The perinatal mortality rate (PMR) and prematurity rate were not different from the singletons, and compared favourably with the PMR reported in the literature for multiple gestations which did not undergo any intervention during pregnancy. This increased abortion rate following amniocentesis may only represent the increased natural loss rate in multiple gestations, and not indicate any increased risk added by the procedure.  相似文献   

20.
First trimester prenatal cytogenetic diagnosis was attempted in 350 pregnancies after trans-abdominal chorionic villus sampling. The cytogenetic investigation was performed using both a short-term method (24 h incubation) and cell culture. Adequate samples were obtained in 99·1 per cent and in all these cases the fetal karyotype was established. A chromosome abnormality was found in 2·0 per cent of cases. A discrepancy between the karyotype obtained after 24 h incubation and the karyotype in cell culture was observed in 2·3 per cent. Maternal cell contamination in the cultures was confirmed in 13 of 181 cases where the 24 h incubation revealed a male karyotype. Studies of culture morphology showed that colonies of convoluted cells may serve as a marker for contamination with maternal cells in culture. For the present, we recommend using a short-term method as well as cell culture for cytogenetic investigation until the problems with karyotype discrepancy and maternal cell contamination have been further clarified.  相似文献   

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