1/82. 'Identical' twins with discordant karyotypes.A chromosomal abnormality in one of the fetuses of a monozygotic twin pregnancy is a rare phenomenon. In the prenatal unit of our cytogenetics laboratory we have recently come across two such heterokaryotypic twin pregnancies. In both cases ultrasound abnormalities were detected in one fetus of each twin pair. Chromosomal analysis showed that one twin pregnancy was discordant for trisomy 21 and the other for 45,X. Ultrasonographic examination suggested a monochorionic twin pregnancy in each case and dna studies confirmed that both sets of twins were monozygotic. Both pregnancies were terminated. Biopsies taken from different sites of the placentas showed chromosomal mosaicism in both cases. There was no clear correlation between the karyotype found close to the site of the umbilical cord insertion in the placenta and the karyotype of the fetus. Sampling of amniotic fluid from both sacs is recommended in diamniotic twin pregnancies if one (or both) of the fetuses has ultrasound abnormalities, even if the twins are apparently monochorionic.- - - - - - - - - - ranking = 1keywords = pregnancy (Clic here for more details about this article) |
2/82. trisomy/tetrasomy 21 mosaicism in CVS: interpretation of cytogenetic discrepancies between placental and fetal chromosome complements.trisomy/tetrasomy 21 mosaicism was found in chorionic villi (semidirect preparation) obtained from a 40 year old pregnant woman. Since both cell lines were abnormal, the couple elected for pregnancy termination. placenta and fetal tissue samples were obtained for cytogenetic study. Long term cultured villi showed a non-mosaic trisomy 21 karyotype, while other tissues showed either a normal karyotype or normal/trisomy21 mosaicism. These discrepancies could be explained by a modified "bottle neck" embryogenic model with a trisomic zygote and a non-disjunction event taking place in one of the first divisions. Our case emphasises the need for confirmatory studies in other tissues when mosaicism is encountered in chorionic villi, even if all cell lines are abnormal.- - - - - - - - - - ranking = 0.33333333333333keywords = pregnancy (Clic here for more details about this article) |
3/82. tuberous sclerosis with intracardiac rhabdomyoma in a fetus with trisomy 21: case report and review of literature.A large cardiac rhabdomyoma protruding into the left ventricle was diagnosed in a fetus at 21 2 weeks of gestation by grey-scale echocardiography. Obstruction to left ventricular outflow was ruled out by colour and spectral Doppler echocardiography. No other abnormalities were noted and karyotyping by cordocentesis revealed trisomy 21 (47,XY, 21). Post-mortem examination after termination of pregnancy confirmed the prenatal diagnosis of cardiac rhabdomyoma and in addition revealed fetal tuberous sclerosis. Demonstration of cardiac rhabdomyoma by prenatal ultrasound should raise suspicion of the presence of fetal tuberous sclerosis. Despite the incidental association with aneuploidy, fetal karyotyping is suggested for optimal counselling of parents.- - - - - - - - - - ranking = 0.82692813102729keywords = gestation, pregnancy (Clic here for more details about this article) |
4/82. Prenatal ultrasound detection of congenital cataract in trisomy 21.A 45-year-old woman underwent serial ultrasound screening procedures during late first and second trimesters of pregnancy for advanced maternal age. Cultured amniocytes karyotype indicated full trisomy 21. Subsequently, the fetus developed congenital cataract diagnosed at 24 weeks. This is the first antenatal diagnosis of this complication of down syndrome.- - - - - - - - - - ranking = 0.33333333333333keywords = pregnancy (Clic here for more details about this article) |
5/82. prenatal diagnosis of trisomy 20 mosaicism by maternal serum screening for down syndrome.We report two cases of prenatally diagnosed trisomy 20 mosaicism associated with positive down syndrome screening at 16 weeks' gestation. Both infants exhibited normal growth and mental development.These cases suggest that the multiple-marker screening test may play an important role in prenatal detection and diagnosis of chromosomal anomalies in addition to down syndrome.- - - - - - - - - - ranking = 0.49359479769395keywords = gestation (Clic here for more details about this article) |
6/82. Elevated second-trimester maternal serum hCG in patients undergoing haemodialysis.Prenatal down syndrome screening with maternal serum alpha-fetoprotein (AFP) and human chorionic gonadotrophin (hCG) has become common. High levels of maternal serum hCG and low levels of AFP have been associated with an increased risk of fetal down syndrome. In this paper, we report five pregnancies in patients undergoing long-term haemodialysis, all of whom had false-positive second-trimester down syndrome screening results. All of our five patients had extremely high levels of maternal serum hCG, but normal AFP values for their gestational age, and all had serious complications during pregnancy.- - - - - - - - - - ranking = 0.82692813102729keywords = gestation, pregnancy (Clic here for more details about this article) |
7/82. trisomy 21 fetus co-existent with a partial molar pregnancy: case report.BACKGROUND: Approximately 1 in 1,000 pregnancies in the united states are complicated by the presence of a hydatidiform mole. A medline search revealed no reported cases of a trisomic fetus co-existent from 1966-1998. We present the case of a patient, initially found to have hypertension, edema, and proteinuria in the first trimester, and later found to have a partial molar gestation co-existent with a trisomy 21 infant. CASE REPORT: A 31-year-old female presented to her family practitioner in the first trimester and was found to have hypertension and proteinuria. A thorough work-up by a nephrologist revealed no cause. The patient was transferred to the Maternal-Fetal medicine Service at 26 weeks' and 1 day estimated gestational age. An amniocentesis revealed the presence of a fetus with trisomy 21. At 27 weeks' and 3 days estimated gestational age, the patient underwent a cesarean delivery for a non-reassuring fetal heart rate. Pathologic examination of the placenta revealed the presence of a partial hydatidiform molar pregnancy. CONCLUSION: The present account represents the first reported case of a fetus with trisomy 21 co-existent with a partial hydatidiform mole.- - - - - - - - - - ranking = 3.1474510597485keywords = gestation, pregnancy (Clic here for more details about this article) |
8/82. Recurrent trisomy 21 in a couple with a child presenting trisomy 21 mosaicism and maternal uniparental disomy for chromosome 21 in the euploid cell line.recurrence of trisomy 21 was observed in a family in which both parents had a normal chromosome complement. Mosaic trisomy 21 was found in a blood karyotype of the first child, a second pregnancy ended in spontaneous abortion, and a full trisomy 21 was found at prenatal diagnosis of the third pregnancy of this same couple. Although recurrent trisomy 21 may be due to chance, the possibility of germline mosaicism for trisomy 21 in one of the parents has important implications for recurrence risk. Molecular analysis was therefore undertaken in this family to determine the parental origin and the stage of nondisjunction of the extra chromosome 21 in both cases. Although a maternal origin of both instances of trisomy 21 was observed, the mosaic case showed homozygosity for all markers along the duplicated maternal chromosome. Such a finding would normally suggest a postzygotic origin of the trisomy 21. However, the diploid cell line in this same case showed maternal uniparental disomy 21, implying that it was the result of a trisomic conception. We suggest that a somatic nondisjunction in the maternal germ cells is the most likely explanation for these findings. The apparent meiotic II stage of nondisjunction of the nonmosaic trisomy 21 fetus was consistent with maternal mosaicism. A review of the literature for recurrent trisomy 21 cases studied by molecular means, suggests that mosaicism in germ cells may account for more cases than is detected cytogenetically. These results also show that dna marker analysis does not provide a valuable tool for patient counseling in case of recurrent trisomy 21.- - - - - - - - - - ranking = 0.66666666666667keywords = pregnancy (Clic here for more details about this article) |
9/82. Isolated pericardial effusion and transient abnormal myelopoiesis in a fetus with Down's syndrome.Isolated pericardial effusion was detected in a fetus at 34 weeks of gestation. A male infant weighing 2,044 g was born by cesarean section because of a non-assuring fetal heart rate pattern at 35 weeks of gestation. Transient leukocytosis (36,100/microl) with 49% blast cells was seen in this neonate. The infant's karyotype was 47, XY 21. The pericardial effusion disappeared after treatment with prednisolone at a dose of 2 mg/kg/day. hypothyroidism was subsequently found. Thus, the subject patient with Down's syndrome developed isolated pericardial effusion, transient abnormal myelopoiesis (TAM), and hypothyroidism. Because more than 20% of the infants with TAM and Down's syndrome develop acute nonlymphocytic leukemia in early childhood, he is being closely observed.- - - - - - - - - - ranking = 0.9871895953879keywords = gestation (Clic here for more details about this article) |
10/82. prenatal diagnosis of intrahepatic communications of the umbilical vein with atypical arteries (A-V fistulae) in two cases of trisomy 21 using color Doppler ultrasound.We report on two cases of the prenatal diagnosis of arterio-venous communication between the intra-abdominal umbilical vein and atypical arteries. The diagnosis was made by color and spectral Doppler and 'color power angiography'. Both cases presented with hydrops fetalis, one at 14 and the other at 31 weeks of gestation. In the first case, color Doppler demonstrated an atypical arterial vessel connecting the umbilical vein with the aorta; the ductus venosus was patent. echocardiography showed a so-called atrioventricular canal. In the second case, a complex intrahepatic vascular malformation was found. color Doppler demonstrated communications between the umbilical vein and the hepatic artery and an atypical artery; the ductus venosus was patent. In the latter case polyhydramnios, duodenal atresia and macroglossia were additionally detected. In both cases, fetal karyotyping revealed trisomy 21. The first case resulted in a missed abortion, the second in a stillbirth. All findings were confirmed on autopsy. Of interest is that both fetuses were affected with trisomy 21. The increasing use of color Doppler in prenatal diagnosis, especially in hemodynamically compromised fetuses, will help to determine the actual incidence of complex vascular malformations of the umbilical vein and to elucidate the impact of such malformations on fetal outcome.- - - - - - - - - - ranking = 0.49359479769395keywords = gestation (Clic here for more details about this article) |
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