Infrequent mutation in tumor suppressor gene p53 in gestational trophoblastic neoplasia

In order to determine the p53 status of gestational trophoblastic neoplasia, 24 cases of molar pregnancies and two choriocarcinoma cell lines (JAR and JEG-3) were evaluated for the presence of mutations. The evaluation involved the whole coding sequence (i.e. exons 2-11) of the p53 gene with polymerase chain reaction (PCR) amplification of genomic DNA, followed by single strand conformation polymorphism (SSCP) and sequencing. Only one case of hydatidiform mole was found to have a missense point mutation (codon 295, CCT-->CTT, i.e. proline to leucine) of the p53 gene. The results suggest that p53 mutation is rarely involved in the pathogenesis of gestational trophoblastic neoplasia.

Cytogenetic study of spontaneous abortions with the Giemsa banding method

Among 102 spontaneous abortuses karyotyped, 29 were from parents with a history of unexplained recurrent spontaneous abortion (group A), and 73 were from parents without a history of recurrent spontaneous abortion (group B). The mean maternal ages of these two groups were not significantly different. The chromosomal aberration rate in group A was 48.3% and in group B was 53.4%. The difference was not significant. The most common chromosomal anomaly was autosomal trisomies in both groups, while monosomy X was more common in group B. The subsequent spontaneous abortion rate was also not significantly different between the two groups.

Increased level of second trimester maternal serum chorionic gonadotropin in pregnancy with a fetus affected by homozygous alpha-thalassemia 1

With enzyme immunoassay, maternal serum chorionic gonadotropin (MShCG) level was determined in 58 pregnancies affected with fetal homozygous alpha-thalassemia 1. In 40 pregnancies with a gestational age of 10 to 14 weeks, 8 (20%) had an MShCG level above 2.5 multiples of the median (MoM); while in the other 18 pregnancies with a gestational age of 15 to 23 weeks, 14 (78%) had a level above 2.5 MoMs and none had a level below the median. Homozygous alpha-thalassemia 1 of the fetus was associated with an elevated MShCG. Therefore in second-trimester screening for Down's syndrome by measurement of MShCG, homozygous alpha-thalassemia 1 should also be considered if elevated MShCG levels are found.

Prevalence and molecular studies of thalassemia in five aboriginal groups in Taiwan

A total of 1,342 blood samples from five aboriginal groups in Taiwan, comprising 522 of the Ami, 246 of the Bunum, 227 of the Atayal, 214 of the Paiwan and 133 of the Yami group, were collected. A complete blood count was performed in each case. In subjects with a mean corpuscular volume < 85 fl or hemoglobin (Hb) < 12 gm% (female) or 13 gm% (male), quantitation of Hb A2 and DNA analysis of alpha- and beta-globin genes were performed. Alpha-thalassemia was diagnosed by Southern hybridization of subject's DNA to alpha-, and zeta-globin gene fragments, and to Lo probe if needed. DNA from beta-thalassemia carriers was studied by polymerase chain reaction and direct sequencing. In the Ami, 42 (8.2%) were alpha-thalassemia 1 carriers, 42 (8.2%) were alpha-thalassemia 2 carriers, one had Hb H disease, and four (0.8%) were beta-thalassemia carriers. In the Bunun, one (0.2%) was an alpha-thalassemia 1 carrier, and two (0.4%) were alpha-thalassemia 2 carriers. In the Atayal, one (0.2%) was an alpha-thalassemia 1 carrier. In the Paiwan, seven (3.3%) were alpha-thalassemia 1 carriers, and one (0.5%) was an alpha-thalassemia 2 carrier. In the Yami, none were either alpha- or beta-thalassemia carriers. Diverse genetic origin, intragroup breeding and malarial selection may play a role in the significant differences of thalassemia prevalences both between the Chinese and the aborigines, and among different groups of aborigines.

Amniocentesis in mothers who are hepatitis B virus carriers does not expose the infant to an increased risk of hepatitis B virus infection

Sixty-seven pairs of mothers with hepatitis B virus (HBV) surface antigen (HBsAg) and their infants were divided into two study groups to determine the effect of amniocentesis on intrauterine HBV infection. In the first study group (35 pairs), the infant's HBsAg status in cord blood was studied and the results were compared with those obtained in the cord blood from 65 infants born to HBsAg-positive women who did not have an amniocentesis. In the second study group (32 pairs), the HBV status of the infants was studied at the age of three months to five years and compared with the HBV status of 3,454 infants in the National HBV Prevention Program. In the first study group, one sample (2.9%) was weakly positive for HBsAg; while in the first control group, two (3.1%) were positive. In the second study group, three (10%) infants were positive for HBsAg. The failure rates of immunoprophylaxis in the second study and control groups were similar (9.4% vs 11% for HBsAg carrier mothers; 30% vs 14% for HBe antigen-positive carrier mothers). This suggested that genetic amniocentesis did not increase the risk of intrauterine HBV infection.

Prenatal diagnosis of X-linked hydrocephalus in a Chinese family with four successive affected pregnancies

We report on a woman with four successive pregnancies affected with X-linked hydrocephalus (XLH). The first child had prenatal craniocentesis and died in utero. The second child had a postnatal shunting operation, but suffers from severe growth and mental retardation at 5 years of age. In the third pregnancy, prenatal ultrasound detected hydrocephalus at the 16th and 20th weeks of gestation and the pregnancy was terminated. In the fourth pregnancy, ultrasound scanning at the 17th and 20th weeks of gestation revealed no remarkable findings, but hydrocephalus was detected at the 24th week. Autopsy confirmed the prenatal diagnosis. DNA polymorphism analysis of the Bc1I site of exons 17-18 of factor VIII gene of the woman and her last two fetuses seemed to be compatible with a linkage between the XLH locus and factor VIII gene. Although XLH has a variable presentation of ventriculomegaly, ultrasound scanning is still a useful tool for prenatal diagnosis at present. Earlier and more accurate prenatal diagnosis will be feasible with molecular analysis of the XLH locus or its flanking regions.

Alpha-thalassemia in the four major aboriginal groups in Taiwan

A total of 1309 unrelated blood samples from four major Taiwan aboriginal groups, including 522 of the Ami, 246 of the Bunun, 227 of the Atayal, and 214 of the Paiwan groups, were collected. Subjects with a mean corpuscular volume below 85 fl and Hb A2 values below 3.5% were further studied with Southern hybridization to determine the status of alpha-globin genes. In the Ami, 43 (4.1%) chromosomes had alpha-thalassemia 1 and 43 (4.1%) had alpha-thalassemia 2. Of the 43 alpha-thalassemia 1 chromosomes, 33 were of the Thailand, one of the Philippine, and nine of the Southeast Asian deletion. Of the 43 alpha-thalassemia 2 chromosomes, 42 were of the type I rightward deletion and one was of leftward deletion. In the Bunun group, one chromosome (0.2%) was of the Thailand deletion and two (0.4%) were of type I rightward deletion. In the Atayal group, only one chromosome (0.2%) was of the Philippine deletion. In the Paiwan group, four chromosomes (0.9%) were of the Southeast Asian deletion and three (0.7%) were of the Thailand deletion. Among the four groups, the Ami had the highest prevalence of alpha-thalassemia, which was also higher than that of the Chinese living in Taiwan.

Intrauterine death of co-twin in the third trimester: a case report of twin-to-twin transfusion syndrome and cord accident

Intrauterine death of one twin in a monochorionic twin pregnancy is associated with increased mortality and morbidity of the survivor. The exact cause is usually difficult to determine even after delivery. The choice of management for the mother and the viable co-twin is difficult. We report on a case of intrauterine death of one twin with monochorionic placentation. Twin-to-twin transfusion syndrome was suggested by the sonographic findings and evidence of a vascular communication. The co-twin survived for another 39 days without complications after the diagnosis of fetal death. Postmortem examination showed severe torsion and constriction of the umbilical cord at the fetal end with focal deficiency of Wharton's jelly. It is likely that torsion and constriction of the cord was responsible for the one intrauterine fetal death; this so-called "twist amputation" of the cord, on the other hand, contributed to the favorable outcome in the surviving co-twin.

Surface characterization and platelet adhesion studies of plasma-sulphonated polyethylene

Canine platelet adhesion on sulphur dioxide and allyl phenyl sulphone plasma-treated low density polyethylene (LDPE) was studied. Both 5 W plasma excitation energy-treated surfaces showed the highest S:C atomic ratio by ESCA analysis. Surface hydrophilicity increased drastically after plasma treatment. However, surface hydrophilicity decreased with time. This might be due to the diffusion of the hydrophilic functional groups into the bulk of the material and/or the migration of low molecular weight hydrocarbon species into the surface region. The allyl phenyl sulphone plasma-treated LDPE was less platelet-activating in terms of platelet adhesion and spreading and was independent of the different plasma excitation energy levels used. Sulphur dioxide plasma-treated LDPE showed a higher level platelet activation than the untreated LDPE. Among the sulphur dioxide plasma-treated LDPE samples, the sample prepared using the 5 W excitation energy was less platelet-activating than the samples treated by higher plasma excitation energies.

Norplant-2 subdermal contraceptive system: experience in Taiwan

Subdermal Norplant-2 implantation, developed for contraception based on sustained release of levonorgestrel, has already been conducted in many countries around the world. From October 1986 to November 1988, a total of 267 female volunteers were enrolled in Norplant studies at the National Taiwan University Hospital. After a follow-up of 36 months, only one of the 231 evaluable cases (0.4%) became pregnant. The continuation rate was 84.5%, 61.3%, and 52.0% at the end of 12, 24 and 36 months after insertion, respectively. Menstrual problems were the most common adverse effects and were also the main reason for discontinuation. In the 23 patients who wished to become pregnant, fertility occurred soon after removal of the Norplant implant. After insertion, serum total cholesterol and triglyceride levels significantly decreased and the hemoglobin concentrations were increased. No liver or renal toxicities were detected. The data suggest that Norplant-2 is a highly effective, safe and long-acting method of reversible contraception. It would be worthwhile to introduce this contraceptive system into Taiwan's family planning program.

Prenatal diagnosis of Hb H disease due to compound heterozygosity for South-east Asian deletion and Hb constant spring by polymerase chain reaction

A pregnant woman has two children affected by moderately severe Hb H disease due to compound heterozygosity of South-east Asian deletion and Constant Spring mutation. In her third pregnancy, transabdominal chorionic villus sampling was performed at the tenth gestational week to obtain fetal DNA. The polymerase chain reaction was used for detection of both the South-east Asian deletion and the Constant Spring mutation. Hb H disease was diagnosed in the fetus. After genetic counselling, the couple elected to have the pregnancy terminated.

Rapid detection of human hemoglobin Quong Sze by polymerase chain reaction

Human hemoglobin Quong Size is a nondeletional defect involving codon 125 of the alpha 2-globin gene. The molecular defect is a T to C mutation, therefore, a new MspI site (CCGG) is created. Using a pair of flanking DNA primers and polymerase chain reaction, a DNA fragment of 339 basepairs (bp) was amplified. After MspI restriction and gel electrophoresis, the mutation could be clearly identified by the presence of two fragments, 108 and 123 bp. This method is rapid and simple and will be very useful in the genetic counseling of Southeast Asians, including the Chinese, in which nondeletional alpha-thalassemia defects are common.

Rapid detection of Chinese G gamma+(A gamma delta beta)zero-thalassemia by polymerase chain reaction

The Chinese G gamma+(A gamma delta beta)zero-thalassemia is caused by a deletion of more than 80 kilobases. It has a beta(+)-thalassemia phenotype and should be differentiated from other mutations causing beta-thalassemia. Using polymerase chain reaction with three oligonucleotide primers bridging the breakpoints, the deletion can be detected easily. The method is useful in the genetic counseling and prenatal diagnosis of the at-risk families.

Rapid prenatal determination of fetal sex by polymerase chain reaction on amniocyte DNA

Sex determination in early gestation is important for fetuses at risk for X-linked disorders or congenital adrenal hyperplasia. One hundred and seventy consecutive samples of amniocytes were collected between the 12th and 31st gestational week. Seven women received early amniocentesis before the 14th week. Fetal sex was determined by amplification of Y-specific DNA fragments within five hours. All results of the polymerase chain reaction, except for one false-negative, were compatible with cytogenetic analyses. Polymerase chain reaction of amniocyte DNA provides a rapid technique for sex determination in early gestation with high specificity and sensitivity.

Combined cornual pregnancy and intrauterine twin pregnancy after in vitro fertilization and embryo transfer: report of a case

A case of combined cornual pregnancy and intrauterine twin pregnancy after in vitro fertilization (IVF) and transfer of six embryos is presented. The case was diagnosed as intrauterine triplets ultrasonographically at seven weeks of gestation. Unfortunately, the patient suffered from severe lower abdominal pain and hypovolemic shock at 10 weeks of gestation, and an emergent laparotomy was done. During the operation, a ruptured cornual pregnancy with accompanying hemoperitoneum was found. Because fetal heart beats were not detected by intraoperative ultrasonography in the other two intrauterine fetuses, evacuation of the gestational contents through the uterine defect was done, and the rupture site was repaired. The incidence, mechanism and management of heterotopic pregnancies after in vitro fertilization and embryo transfer are discussed.

Dystrophin gene deletion in Chinese Duchenne/Becker muscular dystrophy patients via multiplex DNA amplification

Duchenne/Becker muscular dystrophy (DMD/BMD) is a progressive muscle-wasting disease. The dystrophin gene responsible for the disease is the largest human gene ever cloned and is prone to gross gene deletion in two "hot spot" regions. Using nine pairs of oligonucleotide primers deduced from the two regions, we have screened 23 unrelated Chinese DMD/BMD patients by multiplex polymerase chain reaction. Nine (39%) patients were noted to have gene deletion, one in the 5' terminus and eight in the distal half of the gene. The incidence is similar to that reported in other large series mainly on Caucasian patients. The "hot-spot" regions also seem to be present in Chinese patients. Multiplex gene amplification for deletion analysis is useful in the diagnosis of patients with neuromuscular diseases and is an important aid in the prenatal diagnosis and genetic counseling of at-risk families.

Hydrops fetalis caused by severe alpha-thalassemia

Alpha-thalassemia is a prevalent condition in South East Asia and spreading because of increasing immigration. Hemodynamic study of Hb Bart's hydrops fetalis, the most severe form of alpha-thalassemia, showed the fetuses were in a hyperdynamic circulatory state and were also more acidotic, hypoxic, and hypercarvic than normal fetuses. The most common molecular defects of Hb Bart's hydrops fetalis was the Southeast Asia type deletion. Prenatal diagnosis of Hb Bart's hydrops fetalis and HbH diseases has been achieved using chorionic villi sampling or fetal blood sampling.

Pericentric inversions of chromosome 9 in Taiwanese fetuses

Using trypsin-Giemsa banding, a total of 1,350 unrelated Chinese fetuses were studied for pericentric inversion of chromosome 9 [inv(9) (p11; q13)]. Sixteen cases (1.2%) were found to have this variant. The prevalence was higher than that in a previous report on Asians. All the fetuses with inv(9) were born with a normal phenotype.

Prenatal cytogenetic diagnosis in amniocentesis

From 1982 to 1990, cytogenetic studies were successfully conducted in 2,975 (96.19%) of the 3,096 pregnant women who underwent amniocentesis. The average maternal age was 33.7 years and the average gestational age was 18.1 weeks. Common indications of amniocentesis included advanced maternal age (AMA) (54.76%), previous fetus with chromosomal aberrations (6.82%) or gross anomalies (5.01%), intrauterine gross anomaly (4.97%) and maternal exposure to drugs or radiation (5.28%). Among the 89 cases (2.99%) with detected chromosomal aberrations, 53 were numeric (31 trisomies, 21 sex chromosome aberrations and one tripoidy) and 36 were structural (six de novo and 30 hereditary structural rearrangement). The incidence of chromosomal aberrations was 2.03% in cases with AMA. While only four of the 143 cases with previous fetal trisomy 21 had recurrence, the recurrent rate was 90.91% in 11 cases with previous fetal chromosomal translocation. Thirty (20.27%) of the 148 cases with abnormal sonograms showed chromosomal aberrations. Certain congenital anomalies are closely associated with cytogenetic changes: duodenal atresia and trisomy 21; cystic hygroma and 45,X; and polyhydramnios and trisomy 18. Only two of the 157 cases with indications of drug or radiation exposure had abnormal cytogenetic studies. Two of the 53 cases with detected numerical aberrations (47,XXY and 47,XXX) and 27 cases with hereditary structural rearrangement elected to continue their pregnancies. All of these babies were delivered without gross anomalies. This study suggests that for prenatal diagnosis. However, complementary measures, such as routine antenatal ultrasound and maternal serum alphafetoprotein, should be added to increase the efficacy of genetic amniocentesis.

Carrier detection and prenatal diagnosis of alpha-thalassemia of Southeast Asian deletion by polymerase chain reaction

Alpha-thalassemia of Southeast Asian deletion (-- SEA/) is very common in Southeast Asia. Homozygosity of this genotype is the major cause of Hb Bart's hydrops fetalis in Taiwan. With polymerase chain reaction using three oligonucleotide primers bridging the common deletion breakpoint, a DNA fragment of 194 basepairs (bp) was amplified in chromosomes with the -- SEA determinant and a DNA fragment of 287 bp was amplified in chromosomes without this deletion. In our pilot study including 8 normal subjects, 20 obligate carriers, and 11 homozygotes of the deletion, all the genotypes were determined and then confirmed by Southern blotting and DNA hybridization with phi zeta globin gene probe. For prenatal diagnosis, 55 at-risk pregnancies were collected. Chorionic villus sampling was done in 51 cases and early amniocentesis was done in 4 cases. Fourteen cases (25.5%) were diagnosed as normal, 25 (45.5%) as heterozygotes, and 16 (29%) as homozygotes of -- SEA. All of the diagnoses were also confirmed as aforementioned. With polymerase chain reaction, the determination of the -- SEA deletion is straightforward and is much quicker and easier than with conventional Southern blotting and DNA hybridization. In areas with a high prevalence of -- SEA deletion, this method provides a rapid tool for carrier detection and prenatal diagnosis.

Molecular characterization of severe alpha-thalassemias causing hydrops fetalis in Taiwan

alpha-Thalassemia hydrops fetalis is a common disorder in Taiwan. The condition causes perinatal death and many maternal obstetrical complications. In order to determine the molecular defects of this condition in Chinese, 87 unrelated families with this disorder were collected in the past 4 years. The molecular defects were studied by Southern blotting and DNA hybridization with phi zeta 1-globin gene and LO (a 0.4 kb BamHI/EcoRI fragment in the 5' flanking region of the zeta 2-globin gene) probes. Eighty-one (93.1%) fetuses had homozygous Southeast Asian deletion (- -SEA/- -SEA). Five (5.7%) fetuses were compound heterozygotes for the Southeast Asian deletion and Thailand deletion (- -SEA/- -THAI). The remaining fetus was a compound heterozygote for the Southeast Asian deletion and an uncharacterized nondeletional defect (- -SEA/(alpha alpha)Th). The molecular defects of alpha-thalassemia hydrops fetalis in Chinese are heterogeneous. This fact has important implications for genetic counseling and prenatal diagnosis.

Antenatal ultrasonic findings of craniofacial malformations

Fetal craniofacial malformations were identified sonographically in 13 cases. Holoprosencephaly and median cleft syndrome were the most frequent findings. Cleft lip, cleft palate, single nostril, cyclopia and hypotelorism were also seen. Seven of the 13 cases (54%) had polyhydramnios. Amniocentesis was performed on 12 fetuses, and 5 of them showed autosomal trisomy. Accordingly, when craniofacial malformation is recognized antenatally, a careful survey of the fetus for other associated structural anomalies and cytogenetic study are indicated to aid in diagnosis and subsequent obstetric and neonatal management. Also screening for fetal craniofacial malformation is recommended during mid-trimester ultrasound examinations.

Selective reduction of multiple pregnancies in the first trimester or early second trimester

Nine cases of multiple pregnancies, including 7 sets of triplets and 2 sets of quadruplets, were enrolled for selective fetal reduction between March 1989 and July 1990 at the National Taiwan University Hospital. Under transabdominal or transvaginal ultrasound guidance, potassium chloride was injected into the fetal cardiac chamber to kill the selected fetus during the 10-14th gestational week. The number of fetuses was reduced to two in all cases. No maternal complications occurred during the procedure. Six gravidas have given birth to 6 sets of healthy twins; two pregnancies are progressing smoothly at 26 and 23 weeks of gestation, respectively, and one case underwent spontaneous abortion 4 weeks after the procedure. Selective fetal reduction under ultrasound guidance is an acceptable method of preventing high perinatal mortality and morbidity of immature fetuses in grand multiple pregnancies.

Detection of beta-globin gene mutations by polymerase chain reaction

The polymerase chain reaction and oligonucleotide probe hybridization technique were applied to the detection of two common mutations of the beta-globin gene found in Chinese, namely the 4-base pair deletion at the 41-42 codons and the C to T substitution at nucleotide 654 of IVS-2. The accuracy of the method was established using beta-thalassemia cases with known mutations or haplotypes of the restriction fragment length polymorphism (RFLP). A further 11 cases of thalassemia intermediate and thalassemia minor were then analysed with the same approach. Our results showed that 5 of the 11 cases carried the TCTT-deletion at codons 41-42. Our method is economical both in terms of materials and time needed and in an alternative to the use of the molecular RFLP approach in the prenatal diagnosis of beta-thalassemia.