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PubMed1990

Diagnosis of neurofibromatosis I by using tightly linked, flanking DNA markers.

We tested 132 individuals from 21 families segregating an allele for neurofibromatosis type 1 (NF-1), by using nine RFLPs tightly linked to the NF-1 locus. Family members had requested DNA testing either to determine whether "at risk" children were carrying the NF-1 allele or to determine whether their respective families would be informative for prenatal testing. Predictions about whether a child carries the NF-1 mutation were possible for all 32 at-risk offspring (greater than 98% accuracy based on the recombination estimates currently available for these DNA markers). At least one informative probe was available for all 23 matings in these 21 families; flanking markers were informative for 10 matings. Pairwise analysis showed that several of the polymorphisms were in tight linkage disequilibrium; few recombination events were observed with these markers in the families under study. We conclude that the DNA probes used in this study perform well for diagnostic testing of NF-1 in familial cases. A subset of five probe-enzyme systems (pHHH202/RsaI, p11-3C4.2/MspI, pTH17.19/Bg/II, p11-2C11.7/BamHI, and p11-2F9.8/TaqI) provide reliable linkage information for both clinical testing and prenatal diagnosis.

Alleles↗
PubMed1994

[The attitude of family members with polycystic kidney disease to the disease and presymptomatic testing].

BACKGROUND: The application of presymptomatic diagnosis of polycystic kidney disease (PKD) relies on satisfactory collaboration between the affected families and the team of health workers. The objective of the present study was to assess the initial level of knowledge of the disease and its hereditary character, the attitudes of families with PKD to presymptomatic and prenatal testing focused on methods of molecular genetics as well as attitudes to induced abortion if the gene of PKD is detected in the foetus. METHODS AND RESULTS: In a group of 104 subjects who had genetic examinations on account of familial PKD by means of questionnaires knowledge of the diagnosis, clinical and genetic prognosis and attitudes to presymptomatic and prenatal genetic tests were investigated. About 75% of the members of the group had adequate knowledge of the name of the disease and description of the clinical picture, 96.1% were informed on the hereditary character of the disease but only 1.9% knew details about the heredity. The scope of genetic risk was mentioned by some 30%, 51% were unable to express their opinion on the risk. A positive attitude to testing for the presence of the PKD gene was recorded in almost 100% if they themselves were concerned, 94% when their offspring under age was concerned but only 19.2% when the foetus was concerned. Only 5.3% of the respondents would agree with induced abortion in case of positive prenatal evidence of the PKD gene in the foetus and a few more respondents (14%) were opposed to abortion and some 80% were unable or unwilling to express their opinion. CONCLUSIONS: In members of families with PKD an important role is played by knowledge of clinical and genetic aspects of the disease. Genetic counselling must be part of comprehensive care and should always precede indication of molecular genetic methods (DNA analyses).

Adolescent↗
PubMed1996

The relationship between characteristics of obstetrician-gynecologists and rates of recommended prenatal care screening tests.

OBJECTIVE: To examine the relationship between characteristics of obstetrician-gynecologists and rates of recommended prenatal care screening tests. DESIGN: Retrospective review of prenatal care records. SETTING: Prudential HealthCare. PARTICIPANTS: Enrolled women (2184) between 14 to 47 years of age who delivered a live birth in 1992, and saw an obstetrics and gynecology (OB/GYN) physician for prenatal care. MAIN OUTCOME MEASURE: Receipt of routine prenatal care screening tests. RESULTS: Pregnant women received most of the recommended prenatal care screening tests more than 90% of the time, with the exception of urinalysis (68.3%), alphafetoprotein (72.1%), glucose challenge (87.5%), and repeat haemoglobin/hematocrit (71.0%). Rates of receiving recommended screening tests varied by obstetrician's gender and number of years since medical school graduation. Women were more likely to receive an antibody test if they saw a female rather than a male obstetrician (p < 0.05), and more likely to receive syphilis serology, rubella, glucose challenge and repeat hemoglobin and/or hematocrit tests if they saw an obstetrician who graduated from medical school within the past 30 years (1965 or later), rather than an obstetrician who graduated more than 30 years ago (p < 0.05). CONCLUSION: The receipt of prenatal care screening tests varies by characteristics of OB/GYN physicians. The results of this study suggest that targeting educational opportunities to OB/GYN physicians whose year of medical school graduation is 1965 or earlier may improve rates of recommended prenatal screening tests.

Adolescent↗
PubMed2005

Prenatal restraint stress and long-term affective consequences.

Chronic or repeated stress during critical periods of human fetal brain development has been associated with various learning, behavioral and/or mood disorders in later life. In this investigation, pregnant Fischer 344 rats was individually restrained three times a day for 45 min during the last week of gestation in transparent plastic cylinders while at the same time being exposed to bright light. Control pregnant females were left undisturbed in their home cages. Anxiety and depressive-like behavior was measured in the offspring at an age of 6 months using the open field test, the home cage emergence test and the forced swim test. Prenatally stressed rats spent more time in the corners and less time along the walls of an open field, while no difference in total distance moved was observed. In addition, prenatally stressed rats took more time to leave their home cage in the home cage emergence test. On the other hand, no differences in immobility were observed in the forced swim test. Moreover, prenatally stressed rats showed lower stress-induced plasma corticosterone levels compared with control rats. Prenatal stress (PS) had no effect on the number of 5-bromo-2-deoxyuridine-positive cells - used as a measure for cell proliferation - in the dentate gyrus of these rats. These data further support the idea that PS may perturb normal anxiety-related development. However, the present data also suggest that an adaptive or protective effect of PS should not be ignored. Genetic factors are likely to play a role in this respect.

Adaptation, Physiological↗
PubMed2006

Maternal urinary steroid profiles in prenatal diagnosis of Smith-Lemli-Opitz syndrome: first patient series comparing biochemical and molecular studies.

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder caused by reduced activity of 7-dehydrocholesterol (7DHC) reductase, resulting in a decreased level of cholesterol and increased concentrations of 7DHC and 8DHC in body fluids and tissues. Ten pregnancies at 25% risk of SLOS underwent prenatal testing. Diagnostic studies included DHCR7 mutation analysis in chorionic villus samples, amniotic fluid sterol analysis and serial measurements of oestriol (E3), pregnanetriol (PT), 7-dehydropregnanetriol (7DHPT) and 8-dehydroesteriol (8DHE3) concentrations in maternal urine samples obtained between 9 and 20 weeks of gestation. All tests were diagnostic and revealed nine unaffected foetuses (two normal homozygotes and seven DHCR7 heterozygotes) and one affected foetus. In the affected pregnancy, 7DHC and 8DHC in amniotic fluid were 9.87 and 3.7 microg/ml, respectively [reference range (RR) 0.0026 +/- 0.0015 microg/ml and not detectable, respectively] and maternal urinary steroid analyses showed increased ratios of 7DHPT/PT and 8DHE3/E3 of 0.74 and 1.7, respectively (RR 0-0.0147 and 0-0.019). In the heterozygous foetuses, 7DHPT/PT and 8DHE3/E3 ratios did not exceed those found in 48 normal controls. This is the first series of prenatal diagnostic testing for SLOS where non-invasive biochemical testing was performed in tandem with invasive diagnostic testing. We conclude that steroid measurements in maternal urine are a reliable means of prenatal diagnosis for SLOS.

Adult↗
PubMed1994

Demand for predictive genetic testing for Huntington's disease in Australia, 1987 to 1993.

OBJECTIVE: To assess the demand for genetic testing for Huntington's disease among at-risk individuals and for prenatal testing among parents at risk of transmitting the disease, from January 1987 to March 1993. METHODS: Questionnaires were sent to all State coordinators of genetic testing services. RESULTS: One hundred and ninety adults (5.5% of those at risk) and 56 fetuses were tested. Nine per cent more women than men used the service. Most people tested were married and had offspring. Men generally presented for testing at an older age than women. CONCLUSION: The low uptake for testing is not surprising given the severity and untreatability of the illness. Careful monitoring is required, particularly of the effects on individuals told of their genetic status and of possible abuse of the information by third parties.

Adolescent↗
PubMed2003

Prenatal diagnosis of Down syndrome: ten year experience in the Israeli population.

Second trimester maternal serum biochemical markers, introduced between 1990 and 1995, were supplemented with new ultrasound methods at 14-16 weeks and first trimester biochemical markers between 1995 and 2000. This study evaluated the effectiveness of a Down syndrome (DS) prevention program among the Israeli Jewish population between 1990 and 2000. We collected data on the total number of prenatal tests performed on Israeli Jewish women, DS cases detected prenatally and DS livebirths in Israel during these years. We also studied the use of the newer screening tests in 1990, 1992, and 2000. Between 1990 and 1995, use of chromosomal studies for DS in this population increased from 11.3% to 21.6% and the percentage of cases detected prenatally from 53% to 70%. However, between 1996 and 2000, even with the new screening methods, the utilization rate remained similar (20.7% and 19.8%, respectively) and the percentage detected prenatally decreased to 61% in 2000. The total cost per case detected increased from $47,971 US dollars in 1990 to $75,229 US dollars in 1992, and to $190,171 US dollars in 2000. Between 1990 and 1995, improvement in the percentage of cases detected prenatally was associated with a significant increase in the amniocentesis rate-both are attributed to the introduction of second trimester maternal serum biochemical marker tests. Unexpectedly, the introduction between 1995 and 2000 of new genetic methods to assess the DS risk did not improve the percentage detected or reduce the amniocentesis rate, and was accompanied by an increased cost per case detected.

Chorionic Gonadotropin↗
PubMed1999

Testing pregnant women for HIV: a survey of obstetricians and review of patient prenatal/obstetric medical records--Connecticut 1996-1997.

High rates of prenatal testing are needed to identify all HIV-infected pregnant women and prevent transmission to their offspring. To evaluate HIV testing of pregnant women in Connecticut, a survey was conducted in 1998 of licensed obstetricians and a review was performed of 992 randomly sampled prenatal and obstetric medical records for births occurring in 1996. Results of the survey indicated that 78.8% of respondents routinely offered HIV counseling and 76.4% routinely offered HIV testing to pregnant patients in 1997. However, only 44% reported that greater than half of their patients were being tested. Providers who had an HIV testing policy that included HIV-testing unless the patient refused had the highest rate (80.8%; P < 0.05). The review of medical records revealed that only 28.8% of women who delivered in 1996 had an HIV test performed during prenatal care. Maternal characteristics associated (P < 0.05) with testing included Hispanic ethnicity (51.8% tested), younger age (53.6%, < 20 years old), having Medicaid (48.0%), hospital clinic services (44.6%), and history of intravenous drug use (IDU) (76.9%). Testing rate varied by hospital from 0% to 82.8%. These results indicate that considerable modification of provider and hospital practices and policies is needed to raise HIV screening rates.

Adult↗
PubMed2001

Prenatal tobacco effects on neuropsychological outcomes among preadolescents.

This study evaluated the relationships between maternal smoking during pregnancy and 10-year-old children's performance on measures of learning, memory, and problem-solving. In this prospective cohort study, mothers were recruited from an urban prenatal clinic in 1982 and 1983 and observed from their fourth prenatal month until the time of the study. At the 10-year visit, 593 children and mothers were evaluated. The prevalence of tobacco use was high in this cohort: 54.3%, 53.3%, and 60% of the women smoked in the first trimester, third trimester, and 10-year assessment, respectively. After controlling statistically for other prenatal substance use, current tobacco, other substance use variables, and multiple sociodemographic covariates, prenatal tobacco exposure was significantly associated with deficits in learning and memory. Specifically, prenatal tobacco exposure was associated with deficits in verbal learning and design memory, as well as slowed responding on a test of eye-hand coordination. In addition, these children demonstrated a reduced ability for flexible problem solving and more impulsivity, as indicated by an increase in perseverative responses on a card-sorting test. Prenatally exposed children did not show attention deficits or increased activity on a continuous performance test.

Adult↗
PubMed1990

Opinion: predictive testing for Huntington disease in childhood: challenges and implications.

Predictive testing for HD strongly highlights the need for autonomy and the need for each individual to decide about his or her willingness-or unwillingness-to obtain genetic information predictive of the future outcome. In respect of this principle, testing for minors should not be offered at the request of a third party, and prenatal testing which would result in the birth of a child at increased risk for HD should, where possible, be avoided. If we accede to the wishes of the parents for their children to be tested, we will have broken the primary principles of confidentiality, privacy, and individual justice that are owed to those children. This could be the thin edge of a wedge which could result in adoption agencies, educational institutions, insurance companies, and other third parties demanding genetic testing for another individual. Despite years of careful planning, predictive testing for HD is turning out to be more complex and challenging than ever expected. We need a great deal of care and concern in developing our response to this challenge. Careful long-term assessment and documentation of the impact of such testing is needed, so that the appropriate guidelines can be developed, guidelines which both protect families with HD and at the same time give individuals the opportunity to participate in predictive testing programs.

Adoption↗
PubMed2026

A Simplified Workflow for the Prediction of Putative Viral Reads Using NIPT Data.

OBJECTIVE: Non-invasive prenatal testing (NIPT) identifies fetal chromosomal abnormalities by sequencing cell-free fetal DNA (cffDNA). Recent studies suggest the prediction of viral sequences from NIPT data, but current methods lack cost-effectiveness for routine use. This study develops a straightforward workflow to investigate potential viral signatures in pregnant women using NIPT data from 888 Iranian participants. METHOD: Two bioinformatic workflows were compared for predicting viral reads: the traditional method involved mapping reads to the human genome, followed by mapping unmapped reads to viral references, and a direct mapping approach to viral genomes, as proposed in this research. RESULTS: While maintaining reproducibility comparable to the conventional method, the proposed workflow minimizes computational complexity and time usage for data processing. Ultimately, this analysis suggested viral DNA in 24.2% of samples, encompassing 29 distinct species, implying the diversity of the maternal virome. CONCLUSION: This study presents a computationally efficient workflow for the in silico prediction of viral-like sequences from routine NIPT data. Further experimental validation is essential to verify the presence, viability, or clinical relevance of these sequences.

Humans↗
PubMed1994

Ranitidine-associated autoimmune hemolytic anemia in a health maintenance organization population.

Reversible hematologic abnormalities including hemolytic anemia [1] with a positive direct Coombs' test have been associated with ranitidine. In addition to the case report cited above, the U.S. Food and Drug Administration had received five other cases of hemolysis associated with recent intake of ranitidine as of February 1991. To investigate the possible association of ranitidine with autoimmune hemolytic anemia, a study was conducted to determine how often diagnoses of hemolytic anemia or abnormal Coombs' test results followed dispensing of ranitidine using the automated medical and pharmacy records of a large health maintenance organization. No occurrences of hemolytic anemia were identified among 12,054 individuals following 38,686 prescriptions for this medication. The 95% upper confidence bound was 3.1 cases/10,000 exposed persons. One abnormal direct Coombs' test with mild anemia was discovered during routine prenatal testing of an asymptomatic patient who was dispensed ranitidine two and a half months previously. Hemolysis, however, was not demonstrated and an association with prior ranitidine use could not be confirmed. Additional analyses indicate that in only 30% of ranitidine courses was a blood count obtained. In those courses with hematocrits below 40%, less than 1% had a Coombs' test performed. Chart review suggests that the majority of individuals with severe anemia have alternative explanations other than autoimmune hemolysis for their anemia. This analysis indicates that ranitidine is unlikely to be a common cause of clinically recognized autoimmune hemolytic anemia and demonstrates the utility of large automated medical and pharmacy data bases to conduct post-marketing studies of spontaneously reported drug effects.

Ambulatory Care↗
PubMed2003

The general practitioner and the "new genetics".

GPs are involved in long term care of patients and families with complex conditions. They juggle the need for medical expertise, the relationships between family members, the cost of expertise, limitations of access, and the medicolegal environment. With this background, the GP is ideally placed to play an active role in the "new genetics". GP consultations involving the new genetics will include diagnostic testing for patients with clinical problems, preconception and prenatal testing for couples in relation to pregnancy, predictive testing for families with some genetic conditions, and community genetic screening in some circumstances. GPs will need to understand the language of the new genetics, undergo continuing education, and receive ongoing support to enable them to communicate effectively with patients and their families. Different models of care incorporating GPs, specialists and allied health professionals can be developed to provide maximum delivery of relevant genetic data for both genetic and common multifactorial disorders.

Family Practice↗
PubMed2000

[Papanicolaou test in pregnancy].

OBJECTIVE: To investigate the necessity, safety and acceptability of routine Papanicolaou (Pap) smear in pregnant women and cytological characteristics of the smears during pregnancy. METHODS: Pap smear were performed in 954 pregnant women, 1,053 normal controls and 1,908 gynecological out-patients. The cytological preparations were analyzed by using PAPNET method and following Bethesda (TBS-NCI) diagnostic criteria. Quality control was carried out by following TBS-NCI standard. RESULTS: Abnormal epithelial change was found in 89 women (89/954, 9.3%) of pregnant group, which was quite similar to normal controls group and gynecological group. Occurrence rate of cervical squamous intraepithelial lesion (SIL) was the lowest in pregnant group (0.94%, 9 in 954 cases), comparing with control group (2.75%) and gynecological group (6.23%). However, pregnant group had the highest infection rate (89.9%), as compared to gynecological group (64.5%), and normal controls group (69.1%) (P < 0.01). CONCLUSIONS: Cervical Pap smear test is necessary, safety and acceptable for routine prenatal tests. Any pregnant women with infections must be treated as nonpregnant one.

Adult↗
PubMed1990

First trimester diagnosis of cystic fibrosis with linked DNA probes.

In late 1985 the cystic fibrosis (CF) gene was located to chromosome 7, at 7q 22/31. Several restriction fragment length polymorphism (RFLP) markers are closely linked to the CF gene. These markers permit accurate first-trimester prenatal diagnosis based on analysis of chorionic villus DNA by studies of families with one or more affected children. In our laboratory 13 families at risk of having a child with CF have been counselled by the use of linked DNA probes: xV-2c; pCS.7; Met H; Met D; pJ3.11; KM 19. In all cases one or more of the mentioned probes were sufficiently informative to allow first-trimester prenatal diagnosis. In four of the 13 families tested prenatal diagnosis have been performed.

Cystic Fibrosis↗
PubMed2000

Down syndrome: prenatal risk assessment and diagnosis.

Down syndrome (trisomy 21) is the most commonly recognized genetic cause of mental retardation. The risk of trisomy 21 is directly related to maternal age. All forms of prenatal testing for Down syndrome must be voluntary. A nondirective approach should be used when presenting patients with options for prenatal screening and diagnostic testing. Patients who will be 35 years or older on their due date should be offered chorionic villus sampling or second-trimester amniocentesis. Women younger than 35 years should be offered maternal serum screening at 16 to 18 weeks of gestation. The maternal serum markers used to screen for trisomy 21 are alpha-fetoprotein, unconjugated estriol and human chorionic gonadotropin. The use of ultrasound to estimate gestational age improves the sensitivity and specificity of maternal serum screening.

Algorithms↗
PubMedDate not supplied

Prenatal diagnosis of oculocutaneous albinism type I: review and personal experience.

Oculocutaneous albinism type I (OCA I) comprises autosomal recessive syndromes of hypopigmentation and low vision, caused by the lack of tyrosinase activity. Affected families seek genetic counseling and prenatal diagnosis as preventive measures. Until recently, prenatal diagnosis of OCA I was achieved by histologic and electron microscopic examination of fetal skin biopsies. Lately, a molecular genetic approach has become possible by the identification of the two mutated copies of the TYR gene, coding the tyrosinase, in which over 60 mutations have been identified. We report here our experience in prenatal diagnosis of OCA I using the two strategies. Thirty-four prenatal tests were performed in fetuses at risk for OCA I. In 31 cases the diagnosis was made in fetal scalp biopsies using the histological approach. The microscopic observations revealed normal melanogenesis in 26 biopsies. Five albino fetuses were diagnosed by the demonstration of arrest of melanogenesis in early stages I and II. In three pregnancies, molecular genetic tests were performed on DNA extracted from amniocytes, using direct mutation analysis (in one), and complemented by linkage analysis (in two). One albino and two normally pigmented fetuses were diagnosed. The prenatal molecular genetic test can be applied to families when at least one mutation is diagnosed in the albino patient. The histological approach is applicable in all families at risk for OCA I.

Albinism, Oculocutaneous↗
PubMed2004

Cost utility of prenatal diagnosis and the risk-based threshold.

BACKGROUND: Prenatal testing guidelines recommend offering amniocentesis or chorionic villus sampling to women aged 35 years or older, or who have been found by screening to be at a similarly high risk of giving birth to an infant with Down's syndrome or another chromosomal abnormality. This threshold was chosen, in part, because 35 was the approximate age at which amniocentesis was cost beneficial when testing guidelines were developed in the USA in the 1970s. We aimed to assess the economic validity of thresholds based on age or risk for offering invasive prenatal diagnosis. METHODS: We did a cost-utility analysis of chorionic villus sampling and amniocentesis versus no invasive testing using data from randomised trials, case registries, and a utility assessment of 534 diverse pregnant women aged 16-47 years. FINDINGS: In the USA, compared with no diagnostic testing, amniocentesis costs less than US15000 dollars per quality-adjusted life year gained for women of all ages and risk levels. The results do not depend on maternal age or risk of Down's syndrome-affected birth. The cost-utility ratio for any individual woman depends on her preferences for reassurance about the chromosomal status of her fetus, and, to a lesser extent, for miscarriage. INTERPRETATION: Prenatal diagnostic testing can be cost effective at any age or risk level. Current guidelines should be changed to offer testing to all pregnant women, not just those whose risk of carrying an affected fetus exceeds a specified threshold.

Abortion, Spontaneous↗