Non-mosaic trisomy 20 in amniotic fluid cultures with minor anomalies in the fetus

A non-mosaic trisomy 20 was discovered in all cells in two separate cultures from an age-related genetic amniocentesis. Karyotypes of cells obtained via amniocentesis at the time of termination and of cells cultured from the placenta gave the same unambiguous results. However, the fetus, under macro- and microscopic analysis, showed only two minor anomalies: left simian crease and low-set ears. These findings are more suggestive of a normal or at most mosaic trisomy 20 state. The significance of this finding for prenatal diagnosis is discussed.     

De novo trisomy 20p of paternal origin

We report on a case of a de novo trisomy 20p in a 5-year-old boy. The patient presented with dysmorphic features, mental retardation, poor coordination, cardiac malformation, kyphosis, hypospadias, cryptorchidism, and preaxial hexadactyly. No growth delay was noticed. Standard karyotype and FISH techniques allowed the characterization of the chromosome rearrangement showing a duplication spanning almost the whole short arm of chromosome 20. Therefore the karyotype was interpreted as 46,XY,der(20)(pter --> q13.3::p11.2 --> pter). Molecular studies identified the duplication of paternal origin. This is one of the rare reports with almost pure trisomy 20p characterized at the molecular level. Its phenotype is compared to other similar cases described in the literature.     

Follow-up of infants with amniotic fluid trisomy 20 mosaicism

The finding of trisomy 20 mosaicism in amniotic fluid is a cause of considerable anxiety for both physicians and parents. Although the significance of this finding is still not clear, some reassurance can be given to prospective parents, since the outcome has been normal in all reported pregnancies carried to term. Follow-up information on psychomotor development of these infants is needed in order to provide better genetic counseling to these families. We have followed three infants who have had normal growth and psychomotor development up to approximately 2 years.     

Pregnancy: Abnormal amniotic fetal antigen 2 concentrations in trisomy 18 and trisomy 21

Fetal antigen 2 (FA-2) is a human protein, first identifiedin amniotic fluid, and shown to be identical to the aminopropeptideof the ₁ chain of collagen type I. It exists in several differentsize and charge forms. In the present study, FA-2 was measuredin amniotic fluid using two different assays: a rocket lineimmunoelectrophoretic assay which measured total FA-2, and aradioimmunoassay which was specific for the high molecular massforms of FA-2. Both assays gave similar results. FA-2 concentrationswere measured in amniotic fluid samples collected fi om normalpregnancies at 10–23 weeks gestation; they we e shownto rise steeply from 10–14 weeks, peak at 17 weeks andthen fall slightly by 23 weeks. Comparison between amnioticfluid from normal pregnancies and pregnancies affected by trisomy,showed significantly higher FA-2 concentrations in trisomy 21and significantly lower concentrations in trisomy 18.     

胎儿羊水、血清β2-微球蛋白水平分析

目的检测15-38w胎儿羊水、血液β2-微球蛋白（β2-MG）水平，为胎儿泌尿系统疾病等胎儿发育异常的诊断和预后评估提供理论依据。方法应用B超引导下经母腹羊膜腔、脐静脉穿刺术获取121例孕15—38w胎儿羊水和81例19—38w胎儿脐血（经胎血鉴定），应用Bayer1650全自动生化分析仪β2-微球蛋白水平，并进行分组统计。结果胎儿血β2-微球蛋白水平，随孕周增加而下降，但15-34w间无显著差异，而均与35w后组有显著差异；羊水β2-微球蛋白水平。也随孕周增加而下降。但15—30w间无显著差异，31—38w间无显著差异，而两者间组有显著差异，有统计学意义。结论胎儿血、羊水β2-微球蛋白水平随孕周增加而下降，有统计学意义。     

巨大儿孕母血清、羊水、脐血瘦素水平测定及意义

目的探讨瘦素(1eptin)与巨大儿发病的关系.方法应用酶联免疫法(ELISA)检测20例巨大儿(巨大儿组)及20例正常体重儿(对照组)孕母血清.羊水及脐血瘦素水平.结果(1)巨大儿组孕母血清瘦素平均(25.6±8.2ng/rml),羊水瘦素平均(5.9±1.7ng/m1)与对照组(18.8±7.8ng/ml)及(3.9±1.7ng/ml)比较相差显著.分别为(P＜0.05)(P＜0.01).(2)巨大儿组脐血瘦素水平平均(16.8±7.0ng/m1)明显高于对照组(7.7±4.6rg/ml)(P＜0.001).(3)两组孕母血清瘦素与胎儿出生重量无相关性,而脐血瘦素水平与胎儿出生重量呈正相关.(r=0.65,P＜0.01)结论脐血瘦素来源于胎盘及胎儿组织.巨大儿的发病与脐血瘦素水平相关.     

Anti-cardiolipin antibodies in fetal blood and amniotic fluid derived from patients with the anti-phospholipid syndrome

The aim of this study was to investigate whether, in patients with antiphospholipid syndrome, anticardiolipin antibodies pass from mother to offspring sera and amniotic fluid. Eleven patients with antiphospholipid syndrome (study group) and 11 healthy controls, matched by maternal and gestational age (control group) were prospectively examined for the presence of anticardiolipin antibodies in the cord blood during labour, and amniotic fluid during vaginal or Caesarean delivery. Three neonates (27.3%) in the study group had anticardiolipin antibodies in the cord blood, while none had them in the control group. Anticardiolipin antibodies were detected in the amniotic fluid in six (54.5%) of the study group pregnancies, compared with none in the control group. No adverse neonatal outcome was noted except for significantly lower (P < 0.0006) mean birth weight in the study group. Anticardiolipin antibodies can pass the placenta and be detected in fetal cord blood and amniotic fluid. This finding might be used in the future for the assessment of pregnancies with antiphospholipid syndrome.     

Experience with multiple approaches to the prenatal diagnosis of the fragile X syndrome: amniotic fluid, chorionic villi, fetal blood and molecular methods

We have had experience with 160 prenatal diagnosis cases for the fragile X syndrome [fra(X)] or Martin-Bell Syndrome. In 140, amniotic fluid was utilized; 98 had a documented family history of fra(X). The 94 completed cases included 4 no growth; 56 males of which 7 were fra(X)-positive and 2 false-negative; 38 females of which 5 were fra(X) positive. There was no fra(X) positive result when a family history of mental retardation was not documented as fra(X). Molecular methods (RFLPs) were utilized in 10 amniotic fluid and 5 chorionic villus specimens (CVS). Percutaneous umbilical blood sampling was used in 2 negative cases and 1 fra(X) positive case because of timing, tissue culture failure or confirmation of another method. CVS were received in 13 cases, and RFLPs were utilized in 5 of the CVS cases. There was no positive fra(X) CVS chromosome result in males, 1 positive result in a female, but 2 false negatives were detected by RFLPs. On the basis of the results, it can be concluded that cytogenetic and molecular methods are complementary and best used together and that multiple approaches can enhance the efficiency and reliability of fra(X) prenatal diagnosis.     

Antenatal diagnosis of mosaic trisomy 8 confirmed in fetal tissues

An aneuploid karyotype with an extra submetacentric C-group chromosome was observed in all metaphase cells in 5 of 24 primary amniotic fluid cell clones and in admixture with normal cells in two additional clones. Trisomy 8 was demonstrated by R-banding. The parents elected to terminate the pregnancy. Successful cultures were initiated from nine fetal tissues and aneuploid cells were observed in cultures derived from two separate sites in the skin.     

Total cortisol in amniotic fluid and fetal lung maturation.

Total cortisol was determined by radioimmunoassay in 48 samples of amniotic fluid obtained at various stages of normal pregnancy. Before the 34th week, all cortisol levels were less than 40 ng per milliliter. At 35 to 40 weeks the mean value was 2.4 times higher than that at 20 to 34 weeks. In pregnancies greater than 40 weeks, a further increase in total amniotic-fluid cortisol was observed, and values greater than 120 ng per milliliter were found only in patients of this group. A good rank correlation between cortisol and lecithin/sphingomyelin ratio was found in 43 samples (r = 0.83, p less than 0.001). No respiratory-distress syndrome of the newborn occurred when total amniotic-fluid cortisol was greater than 60 ng per milliliter (16 patients). Total amniotic-fluid cortisol may reflect initiation of fetal lung maturation, and may help identify pregnancies with a gestation period of over 40 weeks.     

Improved prenatal detection of fra(X)(q27.3): methods for prevention of false negatives in chorionic villus and amniotic fluid cell cultures

The reliable detection of fra(X)(q27.3) in prenatal samples is important for providing genetic counseling. We have identified 5 new cases of prenatal fragile X [fra(X)] detection in 3 chorionic villus sample (CVS) and 2 amniotic fluid (AF) cell cultures. In 4 of the 5 cases, either excess thymidine (THY) or a combination of THY and 5-fluorodeoxyuridine (FUdR) was clearly superior to FUdR alone as fra(X) inducers. Amniocytes from one case were cultured only in RPMI-1640 and later exposed to FUdR or THY separately. They showed only 2% fra(X) while parallel cultures initiated in Chang medium and incubated in RPMI for at least 7 days (recovery) before fra(X) induction exhibited strikingly increased fra(X) frequencies. Chang medium alone will not allow fra(X) induction in AF (Jenkins EC, Brown WT [1986]: "Genetic Disorders and the Fetus: Diagnosis, Prevention and Treatment." New York: Plenum Press, pp 185-204). Now, using CVS cells, we report that only 1% and 0% fra(X) were detected using FUdR or THY in cells cultured in RPMI for 4 days after removal from Chang medium. Cells with 7 days "recovery" in RPMI exhibited increases from 2 to 6%. Therefore, we have found that Chang medium is very helpful when the appropriate recovery time in another medium is allowed before fra(X) induction. Some false negative reports can be attributed to: induction in Chang medium alone; lack of sufficient recovery time after initiating cells in Chang before induction; and unavailability of the excess THY fra(X) induction system.(ABSTRACT TRUNCATED AT 250 WORDS)     

The biochemical composition of amniotic fluid and of maternal and fetal blood at various periods of pregnancy

Summary The content of sugar, chlorides, urea, nitrogen and of total proteins was studied simultaneously in amniotic fluid maternal and fetal blood. Investigations covered 136 women at various terms of pregnancy (8–40 weeks). With the progress of pregnancy the biochemical composition of amniotic fluid changed as follows: there was a rise of urea, rest nitrogen and of the total protein; sugar concentration dropped; chloride level remained unchanged.There was no parallelism between the biochemical changes in the amniotic fluid on one hand, and the changes in the maternal and fetal blood on the other. The aforementioned biochemical investigations serve as a conclusive confirmation of the secretory theory of the amniotic fluid origin and contradict that of transudation.(Presented by Active Member of the Akad. Med. Nauk SSSR V. V. Parin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 51, No. 3, pp. 64–66, March, 1961     

Prenatal diagnosis of trisomy 20 mosaicism indicating esophageal and rectal origin

Trisomy 20 mosaicism in cultured amniotic fluid cells has in only a few cases been confirmed in fetal tissue. This may lead to the assumption that the trisomic cells are of extra-fetal origin and interruption of the pregnancy is not advisable. Chromosome analysis of numerous fetal tissues indicated in two cases the presence of one or more trisomy 20 cell clones in rectum and esophagus, respectively. The clinical significance of trisomy 20 mosaicism in single organs remains to be elucidated. Besides the karyotype, genetic counselling should take into account all accessible information of the pregnancy, e.g. ultra-sound, serum alpha-fetoprotein values and obstetrical history.     

Catecholamines in amniotic fluid as indicators of intrapartum fetal stress

Catecholamines were measured in the amniotic fluid and in the first voided newborn urine obtained from appropriate-for-date infants of term deliveries. Catecholamine values in the amniotic fluid and urine were nearly equal when expressed in terms of creatinine. Significant positive correlations were observed between the amniotic fluid and urine of norepinephrine and epinephrine. In normal cases (n = 32) that underwent uneventful vaginal delivery, the 95% confidence limits for norepinephrine and epinephrine in the amniotic fluid were 1.53 to 2.33 ng/ml and 0.16 to 0.30 ng/ml, respectively. In cases of moderate stress (n = 12), only norepinephrine showed significantly higher values than the normal cases, while in cases of severe stress (n = 12), norepinephrine became more significantly high, and epinephrine was found to be elevated significantly. A significant difference was noted in the incidence of fetal stress between the infants with more than and those with less than 2.30 ng/ml of norepinephrine, the upper limits of the normal 95% confidence limits. However, for epinephrine such a significant difference was not noted. It was concluded that amniotic fluid catecholamines are of fetal origin and reflect fetal sympathoadrenal activity directly, even during labor, and that their level may be a good indicator of fetal condition and stress.     

Analysis of a case of generalized amniotic fluid embolism by demonstrating the fetal isoantigen (A blood type) in maternal tissues of B blood type, using immunoperoxidase staining

A case of generalized amniotic fluid embolism, confirmed by staining fetal isoantigen in the maternal tissues, is reported. The distribution of emboli may be more accurately evaluated with the immunochemical staining technic than with standard hematoxylin and eosin stain. The severity of the embolic state is evaluated very exactly.     

Comparison of two widely used PCR primer systems for detection of toxoplasma in amniotic fluid, blood, and tissues

The PCR diagnosis of toxoplasmosis suffers from lack of standardization. Interlaboratory comparative studies of PCR methods have been performed, but intralaboratory comparisons are scarce. Here, we optimized and compared the technical performances of two PCR primer systems widely used for Toxoplasma detection. The differences between the two methods were visible only at low parasite concentrations (< or = 1 Toxoplasma genome per reaction tube). Nevertheless, when clinical samples were tested, both methods significantly differed in their technical sensitivities and specificities. Only one method appeared adequate for samples containing blood or tissue.     

Immunocytochemical characterization of amniotic fluid macrophages in cases of fetal neural tube defects

Amniotic fluid cells from 31 pregnancies with fetuses having open neural tube defects (NTDs) and from 43 pregnancies with fetuses free of NTDs were studied with the use of the immunoperoxidase method for alpha-fetoprotein (AFP) and glial fibrillary acidic protein (GFAP). The authors also used cytochemical stains for endogenous peroxidase and nonspecific esterase activity. In cases of NTDs, macrophages were present in the amniotic fluid, and in the authors' system they showed intense immunoreactivity for both AFP and GFAP and showed very strong activity for peroxidase and nonspecific esterase, whereas the epithelial cells and red blood cells showed no activity. In six cases of anencephaly, sections from the margin of the cranial end of defective spinal cords at the aperture of the open lesion were also studied for AFP and GFAP. In these cases, AFP- and GFAP-positive cells were found, indicating the possible neural (glial) origin of a part of amniotic fluid macrophages. Although the determination of AFP levels in maternal blood and amniotic fluid is widely used in the prenatal diagnosis of NTDs, demonstration of AFP in amniotic fluid cells by means of immunocytochemistry has not been described.