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A few fetal diseases may benefit from surgical treatment before birth, but hysterotomy and subsequent delivery by cesarean section pose a risk to the otherwise unaffected mother. To assess maternal risk of mortality, morbidity, and reproductive potential after fetal surgery, we reviewed our experience with 17 highly selected women who underwent fetal surgery. Fifteen of these procedures were performed for one of two congenital anomalies: severe bilateral hydronephrosis and congenital diaphragmatic hernia. There were no deaths or serious maternal injuries. In the 14 women who continued pregnancy after hysterotomy, uterine irritability and preterm labor were frequent complications, requiring early confinement in most cases. There has been no detectable effect on future fertility, as indicated by eight subsequent normal pregnancies. We conclude that hysterotomy for fetal surgery can be accomplished without unduly endangering the mother's life or her future reproductive potential. However, morbidity related to premature labor remains a serious problem, and our ability to control uterine contractions after hysterotomy remains the limiting factor in human fetal surgery. [ABSTRACT FROM AUTHOR]

We have developed a two-colour immunocytochemical staining method for the detection of fetal and embryonic haemoglobin in erythroid cells. The method was applied to study these haemoglobin types in fetal red cells. Specimens from fetal blood (10 weeks), cord blood and fetal liver (14 weeks) as well as chorionic villus samples (10-13 weeks) were stained for gamma and epsilon chains using CY3 and FITC labelled antibodies. Morphometric analysis was applied to determine cell size. Samples from organs involved in early embryonic development contained relatively large erythroblasts expressing the epsilon globin chain (megaloblasts); later in gestation the gamma chain was co-expressed by the same cells which ultimately became smaller and contained HbF (alpha 2 gamma 2) only. This phenomenon was confirmed in CVS samples in which all cell types were abundantly present. Since fetal erythroblasts are considered candidate cells for non-invasive prenatal diagnosis using FISH, we studied the phenotype of erythroblasts circulating in the maternal blood. The majority of erythroblasts in maternal blood appeared to be of the relatively small gamma globin-containing cell type. However, careful screening of the same maternal blood samples also revealed erythroblasts expressing epsilon or epsilon and gamma globins simultaneously, although at low frequency. Control specimens from non-pregnant women did not show nucleated red cells expressing either of the haemoglobin types. These observations may contribute to the better recognition of fetal cells in the maternal blood for prenatal diagnosis.

Latin and Asian-Pacific immigrants are the fastest growing new-comer groups in the U.S. contributing to 85% of immigration totals. New immigrants experience multiple barriers to accessing genetic counseling resulting from cultural, linguistic, financial, and educational factors as well as having unique perceptions on health, illness, reproduction, and life as a whole. In addition, new immigrants lack familiarity with Western medical practices as well as genetic risk and available interventions. We provided perinatal genetic services to 2430 clients, mostly new immigrants of Latin and Asian-Pacific descent over a period of 6 years. Counseling aides sharing the clients' cultural backgrounds were employed. A study assessing the efficacy of cross-cultural education regarding advanced maternal age risk and amniocentesis was implemented and linked to a database containing demographic and clinical information. Practical observations relating to cultural beliefs in the two groups relevant to perinatal genetic counseling were made.

We studied the efficacy of in utero hematopoietic stem cell transplantation and the ability of such transplantation to induce tolerance in a fetal normal mouse allogeneic model. In 9 of the 162 surviving recipients (5.6%), cells of donor origin were detected after birth. The highest engraftment rate was achieved by transplanting fetal liver cells in a relatively high dose (> 10(6) cells/fetal gram). Skin grafting was performed to determine the presence of prenatally induced tolerance. Only those mice which showed evidence of chimerism became tolerant to skin derived from the prenatal donor's strain while remaining competent to reject a skin transplant from a third strain. Tolerant mice could have significant chimerism reestablished by utilizing monoclonal antibody specific for the recipient H-2 antigen as conditioning for IV fetal stem cell retransplantation.

Prenatal testing of 12 pregnancies at risk for argininosuccinic aciduria due to argininosuccinate lyase (ASAL) deficiency and three pregnancies at risk for citrullinaemia due to argininosuccinate synthatase (ASAS) deficiency was performed by metabolite detection in amniotic fluid and measurement of enzyme activity in uncultured and cultured chorionic tissue and in cultured amniocytes. From our data and those of previous studies, amniotic fluid argininosuccinate measurement alone is clearly a reliable and rapid diagnostic test for both severe and mild ASAL deficiency if maternal ASAL deficiency can be excluded. For prenatal diagnosis of ASAS deficiency, however, both measurement of the amniotic fluid citrulline level and enzyme assay should be employed.

Objective: Our purpose was to develop fluorescence in situ hybridization to repetitive chromosome-specific sequences to detect chromosome aneuploidy faster than hybridization to unique targets or karyotyping., Study Design: Aneuploidy involving chromosomes 13, 18, 21, X, and Y comprises 70% of chromosome abnormalities in 10- to 12-week fetuses, 95% of the phenotypically significant newborn chromosome abnormalities. Our improved 8-hour protocol used repetitive probes to label and count the number of these centromeric chromosome domains., Results: This protocol correctly determined chromosome 13, 18, and 21 status in 50 of 50 unselected direct amniocyte samples and found abnormal patterns in 27 of 27 archived trisomy 21 cases. Altogether karyotyping confirmed 744 of 745 chromosome-specific repetitive sequence test results., Conclusion: This protocol rapidly tests abnormal fetuses and newborn infants in whom diagnosis is made at the initiation of labor or before urgent surgery when a cytogenetic result cannot be completed.

Objective: To develop the most up-to-date, complete data base of multifetal pregnancy reduction (MFPR) from cases, and to provide the best counseling for couples with multifetal pregnancies., Methods: From nine centers in five countries, 1789 completed MFPR cases were collected and outcomes evaluated. Pregnancy losses were defined as through 24 weeks and deliveries categorized in groups of 25-28, 29-32, 33-36, and 37 or more weeks., Results: Overall, the pregnancy loss rate was 11.7% but varied from a low of 7.6% for triplets to twins and increased with each additional starting number to 22.9% for sextuplets or higher. Early premature deliveries (25-28 weeks) were 4.5% and varied with starting number. Loss rates by finishing number were highest for triplets and lowest for twins, but gestational age at delivery was highest for singletons., Conclusions: Multifetal pregnancy reduction has been shown to be a safe and effective method to improve outcome in multifetal pregnancies. Outcomes are worse with higher-order gestations and support the need for continued vigilance of fertility therapy.

Objectives: Our purposes were (1) to compare the safety of transabdominal and transcervical chorionic villus sampling with the use of a consistent technique at one center and (2) to determine whether the training of fellows can be accomplished without an increase in the loss rate., Study Design: We performed a retrospective comparison of transabdominal and transcervical chorionic villus sampling loss rates from procedures performed by three principal operators between 1984 and 1992. The type of procedure was chosen by the operator at the time of the procedure on the basis of placental location., Results: Procedures 1 through 2573 were performed solely by transcervical chorionic villus sampling and had an overall fetal loss rate of 5.12%. With the addition of transabdominal chorionic villus sampling the overall fetal loss rate dropped to 3.07% (p < 0.0001). Three and one half years after the start of transabdominal chorionic villus sampling (about 1300 transabdominal chorionic villus sampling procedures), the transabdominal chorionic villus sampling loss rate was significantly better than the transcervical loss rate (p = 0.035), and the difference widened steadily after that. During the same time period seven fellows performed 716 procedures for a fetal loss rate among fellows of 2.72%., Conclusions: (1) Under optimal circumstances (one center, large numbers, few operators, consistent technique, operator choice of best approach), transabdominal chorionic villus sampling may be inherently safer than transcervical chorionic villus sampling. (2) The addition of transabdominal chorionic villus sampling decreases overall chorionic villus sampling loss rates. (3) Although the number of procedures performed by fellows is small, it appears that with close supervision by experienced operators successful training of fellows can be accomplished without adverse effects on loss rates.

Objective: To develop a fetal muscle biopsy technique for immunohistochemical diagnosis of Duchenne and Becker muscular dystrophies., Methods: Data from two clinical centers and one reference laboratory were combined to show 12 completed cases, ten at risk for Duchenne muscular dystrophy, one for Becker muscular dystrophy, and one for mitochondrial myopathy. Samples of fetal gluteal muscle were obtained percutaneously under ultrasound guidance (some with endoscopic assistance) with a biopsy gun. The samples were frozen and assayed for dystrophin by immunohistochemical techniques., Results: Samples were obtained in 11 of 12 (92%) cases, and spontaneous abortion after the procedure occurred in two of 12 (17%) cases. Laboratory diagnoses were possible on small samples, and four of 12 fetuses (33%) were affected. Endoscopy with direct visualization might aid in the procedure., Conclusions: The development of fetal muscle biopsy allows for an expansion of the diagnostic possibilities for myopathies. The experiences of our two clinical centers show that the procedure can be done with accuracy and acceptable safety. The evolving laboratory experience has reduced the amount of tissue necessary for the diagnosis, increased the sophistication of the immunohistochemical analysis, allowed the diagnosis of abnormalities in different parts of the dystrophin gene, and expanded the indications for the use of fetal muscle biopsy. Fetal muscle biopsy can be used successfully for the diagnosis in otherwise uninformative cases, and there is a wide variety of indications beyond traditional Duchenne muscular dystrophy possible, including female fetuses at risk because of X-autosomal translocations.

To further characterize the clinical, radiographic and chondro-osseous morphologic changes in the Desbuquois syndrome, 7 patients from three sibships are described. They all had prenatal onset severe rhizomelic and mesomelic shortness with marked joint laxity and marked micrognathia. Radiographic changes were distinct, consisting of a supernumerary ossification center between the proximal phalanx of the index finger and the second metacarpal, and variable thumb changes. The femoral necks showed enlargement of the lesser trochanter with metaphyseal breaking, producing a characteristic "monkey wrench" (Swedish key) appearance. Growth plate cartilage showed dilated cisterns of rough endoplasmic reticulum in reserve zone chondrocytes. Three of the 7 cases were diagnosed prenatally by second trimester ultrasound and one case by fetoscopy. This syndrome exhibits significant phenotypic variability and must be differentiated from the Catel-Manzke syndrome which exhibits similar radiographic changes in the hands.

Objective: Our goal was to develop the most comprehensive database possible to counsel patients about selective termination for fetal abnormalities, because no one center has sufficient data to assess much more than crude loss rates., Study Design: A total of 183 completed cases of selective termination from 9 centers in 4 countries were combined (169 twins, 11 triplets, 3 quadruplets). Variables included indications, methods, (potassium chloride, exsanguination, air embolus), gestational age at procedure, pregnancies lost (< or = 24 weeks), gestational age at delivery, and neonatal outcome., Results: Indications for selective termination were 96 chromosomal, 76 structural, and 11 mendelian. Selective termination was technically successful in 100% of cases. In 23 of 183 (12.6%) miscarriage occurred before 24 weeks; 2 of 37 (5.4%) occurred when the procedure done at < or = 16 weeks and 21 of 146 (14.4%) when it was done thereafter. Air embolization had a higher loss rate: 10 of 24 (41.7%) compared with 13 of 156 (8.3%) by potassium chloride (chi 2 = 117, p < 0.0001). Three cases of selective termination performed in monochorionic pregnancies all resulted in pregnancy loss. Among 183 potentially viable deliveries, 7 occurred before 28 weeks, 19 at 29 to 32 weeks, 41 at 33 to 36 weeks, and 93 at > or = 37 weeks. Gestational age at delivery was not influenced by the technique used or the indication but was negatively correlated with gestational age at the time of selective termination. No coagulopathy or ischemic damage was observed in survivors. There was no maternal morbidity., Conclusions: (1) Selective termination in experienced hands for a dizygotic abnormal twin is safe and effective when done with potassium chloride. A total of 83.8% of viable deliveries occurred after 33 weeks and only 4.3% at 25 to 28 weeks. (2) Gestational age at the procedure correlated positively with loss rate and inversely with gestational age at delivery; this emphasizes the need for early diagnosis in multifetal pregnancies. (3) Coagulopathy tests are probably unnecessary.

While analyzing 280 hemoglobinopathy kindreds with prescribed molecular tests, 3 unusual mutations were observed that required additional characterization. In the first case, the hypervariable region flanking the alpha-globin genes generated an intermediate length 8.2 kb psi zeta-globin gene fragment on a Southeast Asian chromosome with two deleted alpha-globin genes. Rehybridization of the Southern blot with alpha-globin probe distinguished the mutation unambiguously. In the second case, restriction enzyme analysis of a PCR amplified black beta-globin gene detected a novel beta-83 point mutation adjacent to a promoter element. In the third case, which was uninformative with available allele specific oligonucleotides (ASOs), total genomic PCR amplification and sequencing identified a single basepair insertion in codon 36/37 of an Iranian beta-globin gene that shifted the reading frame and obliterated gene activity. Developing additional region-specific ASOs will further diminish the number of cases that must be characterized by genomic PCR sequencing.

The finding of a 'faint-positive' acetylcholinesterase band in amniotic fluid samples of women at 15 weeks' gestation or above is associated with an increased risk of fetal abnormalities, most commonly gastroschisis. This finding warrants a targeted sonographic evaluation, in order to rule out significant fetal malformations.

Gastroschisis is a rare congenital anomaly characterized by the herniation of fetal intestines directly through an abdominal wall defect. It is associated infrequently with chromosomal or other nonbowel defects and can be treated surgically after delivery, with survival rates reported to be between 87 and 100%. We reviewed 21 cases of prenatally diagnosed gastroschisis to ascertain the effect of fetal growth retardation on perinatal outcome. Ten of the 21 fetuses (48%) were identified prenatally as growth retarded, although only seven of these ten truly had birth weights less than the 10th percentile. Three additional fetuses that had not been identified prenatally as growth retarded did, in fact, have birth weights less than the 10th percentile, for a total frequency of growth retardation at birth of 48% (10/21 fetuses). When compared to non-growth-retarded fetuses with gastroschisis, fetuses who were growth retarded, although more likely to have been delivered by emergency cesarean section, had shorter hospitalization times, were more likely to have undergone primary closure on the first day of life, and had fewer major complications. We conclude that growth retardation is common in fetuses with gastroschisis and the postnatal outcome in gastroschisis is not poorer for fetuses who are growth retarded.

Our Factor VIII and RFLP analyses identified previously unreported grandpaternal hemophilia A mosaicism in a male who transmitted the disease allele to 2 of 4 daughters and 2 of 4 grandsons. An uncommon flanking polymorphic DXS52 allele cosegregated with this grandpaternal mutant allele. This and other reports of mosaic hemophilia A carriers indicate that parental mosaicism can explain unusual segregation of low Factor VIII activities and DNA polymorphisms in about 1% of hemophilia A pedigrees.

All current methods of fetal karyotyping are invasive and carry a definite, albeit small, procedure-related risk. Because of this and testing costs, only women older than 35 years who have a greater risk for fetal aneuploidy are currently offered prenatal testing. But this detects only 20% to 25% of fetuses with Down syndrome. It would be a tremendous advance to find a noninvasive technique for prenatal diagnosis that carries no procedure-related risk and could be offered to all pregnant women. We describe a possible technique for noninvasive prenatal diagnosis that aims to identify fetal cells in the peripheral maternal circulation and successfully garner them for prenatal testing. Early attempts at fetal karyotyping were hampered by inaccurate diagnostic methods and cumbersome cell-counting techniques. Today, improved capabilities of identifying and enriching for fetal cells, coupled with sensitive methods of analysis such as the polymerase chain reaction, bring renewed enthusiasm to this task. Many technical issues, as well as serious questions regarding the test's utility, still exist, however, and must be explored and answered before the capture of fetal cells in the maternal circulation translates into reality for noninvasive prenatal diagnosis.

Modern physicians desire not only to treat but to cure congenital diseases. In a wide variety of diseases, bone marrow transplantation can be the tool of final cure. The limitations and risks of this procedure have motivated researchers to search for an earlier and safer method of treatment. Special features of fetal immune systems make it possible to perform the transplantation during fetal life using fetal hematopoietic stem cells, thus avoiding many of the side effects of bone marrow transplantation in neonatal life. We review the experimental work done with animal models in this field and the human trials that have been published recently.

Invasive prenatal testing has become an important way to evaluate fetuses at increased risk for hereditary disorders. In utero sampling of fetal skin, liver, and muscle may be required to diagnose before-birth disorders that cannot be diagnosed by analysis using chorionic villi or amniotic fluid. In the next few years, many of these conditions will be detected by DNA analysis, and the need for these procedures may decrease dramatically. First performed by fetoscopy, fetal tissue sampling is now most frequently done by inserting a biopsy needle under continuous ultrasonographic guidance. We describe the indications, techniques, complications, and experience with obtaining fetal skin, liver, and muscle biopsy specimens.

From 1978 to 1990, 263 fetuses with an elevated level of amniotic fluid alpha-fetoprotein (AF-AFP) (> 2.0 multiples of the median) were examined with targeted fetal sonography. All cases of AF-AFP elevation among 22,355 genetic amniocenteses were represented. Sonography correctly showed 32 open neural-tube defects, including 20 myelomeningoceles, and depicted 94% (63 of 67) of the anomalous fetuses. Two of five anomalous fetuses with normal sonograms, however, had extremely high AF-AFP levels leading to prospectively correct diagnoses of congenital nephrosis. Therefore, programmatically, 97% (65 of 67) of the anomalous fetuses were recognized. The three programmatic misdiagnoses were all detected in the neonatal period and surgically corrected; subsequent development was normal. The combination of an elevated AF-AFP level and a detailed sonogram allowed distinction between a normal and an anomalous fetus in 99% of cases. When elevated levels are noted, AF-AFP analysis followed by detailed sonography is highly successful for the detection and characterization of anomalous fetuses and the recognition of normal fetuses with physiologic increases of this protein in the amniotic fluid.

Objective: To evaluate the safety and efficacy of transabdominal multifetal pregnancy reduction (MFPR) in the management of iatrogenic and spontaneous multifetal pregnancies., Methods: Data were combined from 463 completed pregnancies that underwent MFPR at major worldwide centers., Results: Multifetal pregnancy reduction was performed with a 100% technical success rate (there were no failed procedures); 83.8% had delivery of potentially viable fetuses (defined as 24 weeks' gestation or later), and 83.5% of these viable pregnancies delivered at 33 weeks or later. The risk of fetal loss was 3.9% at 2 weeks or less post-procedure, 4.6% at 4 weeks or less, and 16.2% at less than 24 weeks of gestation. Gestational age at delivery varied principally with the number of fetuses remaining, with 7.1% delivering prematurely at less than 28 weeks, and 9.4% at 29-32 weeks. The incidence of obstetric and medical complications appeared to be unaffected, and there was no increase in congenital malformations., Conclusions: Multifetal pregnancy reduction is an efficient and safe way of improving outcome in multifetal pregnancies, unambiguously for quadruplets or more, and arguably for triplets. However, particularly at higher starting numbers, there are still suboptimal outcomes. We cannot answer the question of whether MFPR should be offered to women with triplets or twins. The only major risk appears to be fetal loss per se, and because the procedure itself does not damage the survivors, parental autonomy should be given a higher priority in the decision process than previously. However, to obviate the need for this procedure, infertility specialists must continue to be vigilant in the use of fertility drugs.

X-linked ichthyosis results from steroid sulfatase (STS) deficiency; 90% of affected patients have a complete deletion of the entire 146 kb STS gene on the distal X chromosome short arm (Xp22.3). In these families prenatal diagnosis and carrier testing can be completed in 2 days by hybridizing simultaneously 2 different cosmid probes labeled with fluorescein or Texas red and counterstaining interphase nuclear DNA with DAPI. An STS gene probe labeled with Texas red hybridizes specifically to the steroid sulfatase gene on the X chromosome. A second flanking probe labeled with fluorescein hybridizes to both the normal Y chromosome and normal and STS deleted X chromosomes. In this fashion the interphase nuclei of normal males, affected males, normal females, and carrier females can be distinguished unambiguously. Because normal males and carrier females each show two yellow-green fluorescein spots and one Texas red STS spot, use of this test prenatally requires determining fetal sex independently with repetitive X and Y chromosome-specific probes. This procedure can be used with lymphocytes, direct and cultured chorionic villus cells, direct and cultured amniocytes, and fibroblasts. Similar methods are anticipated to be useful for rapid diagnostic assessment of other aneuploid gene disorders.

Xp21 microdeletion syndrome is associated with variable size Xp21 deletions that usually include the glycerol kinase locus. The clinical phenotypes we studied in this chromosome region include: Xpter - Aland Island eye disease (AIED) -adrenal hypoplasia (AH) -glycerol kinase (GKD) -Duchenne muscular dystrophy (DMD) -retinitis pigmentosa (RP) -ornithine transcarbamylase (OTC) -centromere. In a compilation of 18 individuals in 14 families with the AH, GKD, and DMD loci deleted, 17 were male and all were developmentally delayed. In contrast, we report mentally retarded female carriers in two Xp21 deletion syndrome families with DMD, GKD, and AH in affected males. In the first family with normal karyotypes, a submicroscopic deletion was associated with DMD in the retarded male and with retardation in carrier females. In the second family an X chromosome with a cytogenetically deleted Xp21 distal to the OTC and RP genes segregated in the affected male and retarded female carriers. DNA analysis at the DMD locus verified the cytogenetic findings. This report of mental retardation in otherwise asymptomatic female carriers of Xp21 deletion classifies one form of mental retardation in females.

We reviewed our experience with fetal therapy for congenital cystic adenomatoid malformation of the lung (CCAM) at the University of California, San Francisco Fetal Treatment Center. Fetuses with life-threatening CCAM were selected for prenatal treatment according to predetermined guidelines, including the gestational age of the fetus, the size of the intrathoracic lesion, maternal health, and the development of fetal hydrops. The knowledge that fetuses with hydrops are at high risk for fetal or neonatal death led to fetal surgical resection of the massively enlarged pulmonary lobe (fetal lobectomy) in six cases. In the first case, resection was too late, since preoperative labor and maternal preeclampsia could not be reversed, leading to premature delivery of a nonviable infant. In the next four cases, CCAM resection led to resolution of the hydrops, impressive in utero lung growth, and neonatal survival. Right middle and lower lobe resection in the sixth fetus at 21 weeks was successful, but subsequent inexplicable fetal death highlights the need for better postoperative fetal monitoring and treatment. Three other fetuses with a single predominant cyst underwent thoracoamniotic shunt placement alone; two survived after delivery and prompt neonatal surgery with the assistance of high-frequency ventilation or extracorporeal membrane oxygenation. Fetal therapy can now be considered for otherwise fatal space-occupying intrathoracic lesions in the fetus.

Objective: To evaluate the prevalence of velamentous cord insertion in twin-twin transfusion using the hypothesis that such insertions may contribute to the etiology of the condition., Methods: All cases of placentas referred for pathologic evaluation at the University of California at San Francisco from 1984-1992 were reviewed for the citation of diamniotic-monochorionic placentation, including the presence of velamentous cord insertions. Maternal and infant records were studied for findings consistent with twin-twin transfusion syndrome., Results: Thirty-eight cases of monochorionic-diamniotic twins were identified, 11 of which showed twin-twin transfusion syndrome. The prevalence of velamentous cord insertion in the transfusion syndrome subset was 63.6%, compared with 18.5% in those without (significant difference at P < .01). Twin-twin transfusion syndrome pregnancies with velamentous insertions were delivered at a significantly earlier gestational age; they also had fewer surviving infants and were more likely to have been treated prenatally than transfusion syndrome pregnancies without velamentous insertion, although these latter two findings were not significantly different., Conclusions: Velamentous cord insertions are more common in twin-twin transfusion syndrome pregnancies and may contribute to the development of profound disparity in fluid volume because the membranously inserted cord can be easily compressed, reducing blood flow to one twin. Large-volume amniocentesis may reduce this compressive force on the cord insertion, thus explaining the success of this mode of intervention.

The diagnosis of glycogen storage disease type Ia currently uses enzyme analysis of liver tissue. This requires liver biopsy in the at-risk neonate or fetus. Conflicting reports have appeared in the literature on the use of peripheral platelet glucose-6-phosphatase activity for the diagnosis of this disorder. We have applied a sensitive radiometric assay system to the measurement of glucose-6-phosphatase activity in peripheral platelets. Two families with affected members were analysed, revealing no differences in glucose-6-phosphatase activity as compared with control values. Platelet measurement of glucose-6-phosphatase does not appear to be useful for the diagnosis of glycogen storage disease type Ia.

A sorted, cloned Y chromosome phage library was screened for unique Y chromosome sequences. Of the thousands of plaques screened, 13 did not hybridize to radiolabeled 46,XX total chromosomal DNA. Three plaques were characterized further. Clone Y1 hybridized to multiple restriction enzyme fragments in both male and female DNA with more intense bands in male DNA. Clone Y2, also found in female and male DNA, is probably located in the pseudosutosomal region because extra copies of either the X or Y chromosomes increased Y2 restriction enzyme fragment intensity in total cellular DNA. Clone Y5 was male specific in three of four restriction enzyme digests although in the fourth a light hybridizing band was observed in both male and female DNA. Clone Y5 was sublocalized to band Yq 11.22 by hybridization to a panel of cellular DNA from patients with Y chromosome rearrangements. Clone Y5 can be used to test for retention of the proximally long arm Y suggested to cause gonadal cancer in carrier females. The long series of GA repeats in Y5, anticipated to be polymorphic, may provide a sensitive means to follow Y chromosome variation in human populations.

The effect of advancing maternal age on the risk of death of fetuses with certain chromosome abnormalities has been tested by comparing their frequency at the time of chorionic villus sampling (CVS) with that at amniocentesis. The frequency of chromosome abnormalities among women whose sole risk factor for a chromosome abnormality was advanced maternal age (> or = 35 years old) was determined in a pooled group of 15,147 CVS cases, of whom > 1/3 were from the initial 7,500 CVS cases at the University of California, San Francisco, and compared with a pooled group of 74,851 amniocentesis cases collected from the literature. The frequency of trisomy 21 not only increased with advancing maternal age as expected, but the slope of the increase was about 25% greater in the CVS group than in the amniocentesis group (P = 0.08 for the difference in slopes by a logistic statistical model and P = 0.04 by a normit model). Similar patterns were seen for trisomies 18 and 13, but the P values for the differences in slopes were much higher. These results suggest that the miscarriage rate of trisomy 21 during the gestational interval studied is selectively greater with advancing maternal age. The basis for the enhanced selective loss of trisomy 21 with maternal age may be a reduced ability of the ageing "maternal compartment" to compensate for abnormal conceptuses.

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).

Objective: Twenty-two cases of antenatally diagnosed congenital cystic adenomatoid malformations are reported., Study Design: Case management is reviewed., Results: Eighteen women continued pregnancy after diagnosis. In nine cases nonimmune hydrops fetalis did not develop and all infants survived. Nonimmune hydrops fetalis developed in the other nine; fetal intervention was performed in eight cases. In the single case of nonimmune hydrops fetalis without intervention, the neonate died. In four cases aspiration of macrocystic lesions was performed. In two cases cystoamniotic shunts were placed. Neither aspiration or shunting provided long-term benefit. In six cases fetal lobectomy was ultimately performed and four survived. Two fetuses did not undergo in utero surgery; one was delivered prematurely after cyst aspiration and lived, and the other previable fetus was delivered soon after shunting., Conclusions: Fetal survival is best related to development of nonimmune hydrops fetalis. Aspiration of cystic lesions and cystoamniotic shunts generally provide short-term benefit. Early experience with fetal surgery for congenital cystic adenomatoid malformations has been encouraging.

Prenatal diagnosis and carrier detection for Duchenne muscular dystrophy (DMD) usually can be performed using DNA analysis. When recombination occurs within the DMD gene, or DNA analysis is uninformative, or in pedigrees where it is unclear whether or not the consultand is a carrier, direct examination of muscle by dystrophin analysis may provide the only means of prenatal diagnosis. We present three cases representing each of these molecular genetic diagnostic dilemmas. In each instance, we used sonographically guided fetal muscle biopsy for dystrophin protein analysis to resolve the dilemma. In the first and third cases, the presence of normal dystrophin was shown by immunofluorescence and this was followed by delivery of an unaffected male fetus. In the second case, dystrophin was not found in fetal muscle tissue implying that this fetus was affected. The absence of dystrophin and affected status was confirmed in skeletal and cardiac muscle obtained after pregnancy termination.

Maternal serum CA 125 levels were determined at 9-11 menstrual weeks for 26 cases of trisomy 13 (n = 4), trisomy 18 (n = 7), trisomy 21 (n = 15), and appropriate controls. There were no statistically significant differences between groups.

Carrier detection and prenatal diagnosis of Norrie disease (ND) were performed using the polymorphic L1.28, OTC, and 58-1 probes. L1.28 was polymorphic in 3 of the 5 ND families tested and informative in 2 families (40%). Probe 58-1 and OTC were informative in one of 3 families (33%) and in both of the 2 families (100%) tested, respectively. The major allele frequency was 73% in L1.28 (DXS7), 89% in 58-1 (DXS14), and 50% in OTC in our patient population. One of 5 families studies showed a recombination between probes (L1.28 and OTC) and the ND gene locus placing the ND locus proximal to L1.28 and OTC.

Background: Chorionic-villus sampling is done in early pregnancy to obtain fetal cells for the prenatal diagnosis of genetic and chromosomal defects. Transcervical chorionic-villus sampling has been shown to be safe and effective in national trials. Recently, an alternative transabdominal technique has been suggested as potentially easier and safer., Methods: From April 1987 through September 1989, we prospectively compared transcervical and transabdominal chorionic-villus sampling in 3999 women with singleton pregnancies in whom the risk of a genetically abnormal fetus was increased. Women between 7 and 12 weeks of gestation underwent ultrasonographic evaluation of placental and uterine position. Those with active vaginal infections, active bleeding, or cervical polyps were excluded. If the obstetrician thought either sampling procedure was acceptable, the woman was asked to consent to random assignment to one of the two procedures. Both groups were followed to determine the outcome of pregnancy and the rate of spontaneous fetal loss after chorionic-villus sampling., Results: Among the 3999 women who entered the study, sampling was attempted in 3873 (97 percent), 1944 of whom had been assigned to undergo transcervical sampling and 1929 to undergo transabdominal sampling. Of these 3873 women, sampling was eventually successful in 3863. Sampling was successful after a single insertion of the sampling instrument in 94 percent of the transabdominal procedures and 90 percent of the transcervical procedures. Among the women with cytogenetically normal pregnancies who had sampling because of maternal age, the rate of spontaneous fetal loss through 28 weeks of pregnancy was 2.5 percent in the transcervical-sampling group and 2.3 percent in the transabdominal-sampling group (difference, 0.26 percent; 95 percent confidence interval, -0.5 to 1.0 percent)., Conclusions: Transabdominal and transcervical chorionic-villus sampling appear to be equally safe procedures for first-trimester diagnosis of fetal abnormalities.

We have used chromosome-specific repetitive sequences to detect the most common human aneuploidies prenatally. Together chromosome 21, 13, 18, X, and Y aneuploidy comprises 95% of the chromosome abnormalities that result in a high risk of abnormal phenotypes at birth. The X, Y, and 18 repetitive probes work reliably in multiple tissue types including directly examined and cultured amniocytes, chorionic villus cells, lymphocytes, and cultured fibroblasts. The probe that detects both chromosomes 13 and 21 routinely gives results in each cell type tested except directly studied amniocytes which can be interpreted in seven-ninths of the cases with protocol 1 and all tested samples with protocol 2. Our protocols diagnosed trisomy 21 in a 23-week fetus with low maternal serum AFP and a trisomy 18 in a direct chorionic villus sample 2 working days after the samples were obtained. Trisomy 21 also has been ruled out in a CVS karyotype first thought to be 47,XY, +21. These studies reflect the potential value of in situ hybridization to provide a more rapid, less expensive means to screen most at-risk fetal populations with less effort in first world cytogenetic laboratories, and to provide economical cytogenetic services in less developed countries.

In utero stem cell transplantation offers the potential for treating a number of genetic disorders. The combination of fetal immunotolerance and fetal marrow space makes the fetus an excellent transplant recipient. Experiments on the mouse, sheep and rhesus monkey have indicated that in utero transplantation is feasible. Human trials are currently beginning.

Cytogenetic data are presented for 11,473 chorionic villus sampling (CVS) procedures from nine centres in the U.S. NICHD collaborative study. A successful cytogenetic diagnosis was obtained in 99.7 per cent of cases, with data obtained from the direct method only (26 per cent), culture method only (42 per cent), or a combination of both (32 per cent). A total of 1.1 per cent of patients had a second CVS or amniocentesis procedure for reasons related to the cytogenetic diagnostic procedure, including laboratory failures (27 cases), maternal cell contamination (4 cases), or mosaic or ambiguous cytogenetic results (98 cases). There were no diagnostic errors involving trisomies for chromosomes 21, 18, and 13. For sex chromosome aneuploidies, one patient terminated her pregnancy on the basis of non-mosaic 47,XXX in the direct method prior to the availability of results from cultured cells. Subsequent analysis of the CVS cultures and fetal tissues showed only normal female cells. Other false-positive predictions involving non-mosaic aneuploidies (n = 13) were observed in the direct or culture method, but these cases involved rare aneuploidies: four cases of tetraploidy, two cases of trisomy 7, and one case each of trisomies 3, 8, 11, 15, 16, 20, and 22. This indicates that rare aneuploidies observed in the direct or culture method should be subjected to follow-up by amniocentesis. Two cases of unbalanced structural abnormalities detected in the direct method were not confirmed in cultured CVS or amniotic fluid. In addition, one structural rearrangement was misinterpreted as unbalanced from the direct method, leading to pregnancy termination prior to results from cultured cells showing a balanced, inherited translocation. False-negative results (n = 8) were observed only in the direct method, including one non-mosaic fetal abnormality (trisomy 18) detected by the culture method and seven cases of fetal mosaicism (all detected by the culture method). Mosaicism was observed in 0.8 per cent of all cases, while pseudomosaicism (including single trisomic cells) was observed in 1.6 per cent of cases. Mosaicism was observed with equal frequency in the direct and culture methods, but was confirmed as fetal mosaicism more often in cases from the culture method (24 per cent) than in cases from the direct method (10 per cent). The overall rate of maternal cell contamination was 1.8 per cent for the culture method, but there was only one case of incorrect sex prediction due to complete maternal cell contamination which resulted in the birth of a normal male.(ABSTRACT TRUNCATED AT 400 WORDS)

The accuracy of biochemical and molecular prenatal diagnoses using chorionic villi as the fetal source was assessed by seven centres participating in the NICHD collaborative study on the safety and accuracy of chorionic villus sampling (CVS) and amniocentesis. Of 601 pregnancies studied, biochemical methods were used to determine the diagnosis in 283 fetuses at risk for 35 different metabolic disorders. Fifteen different lysosomal storage diseases accounted for 81 per cent of the biochemical prenatal diagnoses performed, with 57 per cent of these pregnancies at risk for Tay-Sachs disease. No errors were made in the biochemical diagnoses that predicted affected or unaffected fetuses. However, the diagnoses of certain disorders (e.g., mucopolysacchariodosis type IH, metachromatic leukodystrophy, and Krabbe disease) occasionally required confirmatory studies in cultured amniocytes because the enzyme results were inconclusive in direct and/or cultured villi or due to the presence of a pseudodeficiency allele. Of these, only the diagnosis of a fetus at risk for Krabbe disease remained inconclusive after special studies to discriminate between mutant and pseudo-deficiency alleles. Recombinant DNA techniques were used to predict the diagnosis of 318 fetuses at risk for 16 different disorders in which the defective disease gene could be detected either directly or by linkage analysis to a nearby polymorphic marker. Of these, 32 per cent were for haemoglobinopathies, 25 per cent for cystic fibrosis, 24 per cent for Duchenne or Becker muscular dystrophy, and 7 per cent for haemophilias. Pregnancies at risk for known disorders with specific molecular lesions (e.g., sickle cell disease) were accurately diagnosed in direct and/or cultured villi. Diagnoses requiring analyses with closely linked polymorphic markers were occasionally uniformative or inconclusive. Maternal contamination was not reported in any biochemical or molecular-based diagnosis. These studies document the high accuracy and rapidity of both biochemical and mutation-specific prenatal diagnoses with direct and cultured chorionic villi.

Norrie disease is a human X-linked recessive disorder of unknown etiology characterized by congenital blindness, sensory neural deafness and mental retardation. This disease gene was previously linked to the DXS7 (L1.28) locus and the MAO genes in band Xp11.3. We report here fine physical mapping of the obligate region containing the Norrie disease gene (NDP) defined by a recombination and by the smallest submicroscopic chromosomal deletion associated with Norrie disease identified to date. Analysis, using in addition two overlapping YAC clones from this region, allowed orientation of the MAOA and MAOB genes in a 5'-3'-3'-5' configuration. A recombination event between a (GT)n polymorphism in intron 2 of the MAOB gene and the NDP locus, in a family previously reported to have a recombination between DXS7 and NDP, delineates a flanking marker telomeric to this disease gene. An anonymous DNA probe, dc12, present in one of the YACs and in a patient with a submicroscopic deletion which includes MAOA and MAOB but not L1.28, serves as a flanking marker centromeric to the disease gene. An Alu-PCR fragment from the right arm of the MAO YAC (YMAO.AluR) is not deleted in this patient and also delineates the centromeric extent of the obligate disease region. The apparent order of these loci is telomere ... DXS7-MAOA-MAOB-NDP-dc12-YMAO.AluR ... centromere. Together these data define the obligate region containing the NDP gene to a chromosomal segment less than 150 kb.

Factors found to be associated with pregnancy loss after transcervical CVS were race (higher for non-white), history of spontaneous abortion, unplanned pregnancy, history of spotting or bleeding during the pregnancy prior to CVS, and placental position (higher for fundal or lateral locations). Whether the increase in loss risk is due to the factor, per se, or the factor plus the CVS cannot be determined due to the lack of appropriate control data.