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PubMed1994

Assessing genetic technologies. Two ethical issues.

Assessment of the impact of genetic technologies requires an understanding of the ethical issues that such technologies raise, which in turn requires an understanding of the social context of genetics. This article discusses 10 factors that characterize the social context of contemporary genetics, and considers two presumptions that usually are unquestioned--first, that more choice is always better; second, that what can be improved should be improved. Recent experience with genetic screening and testing to increase reproductive choice indicates that it is sometimes an ambiguous good. Prenatal testing, which has been guided by an ideology of nondirective counseling, will become increasingly problematic as the menu of possible genetic tests grows longer, because nondirectiveness offers no way to distinguish between significant disease and parental whim. In the realm of reproduction, more choice may also come to mean increasing parental responsibility to have genetically "healthy" offspring. Technologies intended to improve health outcomes may also be used for non-health-related goals--such as to increase athletic performance or to capitalize on social prejudices. Genetic technologies increasingly will challenge the troubled distinction between therapy and enhancement.

Biotechnology↗
PubMedDate not supplied

Molecular biology of the Rh blood group system.

Rh molecular biology has made many advances since the first Rh cDNA was cloned in 1990. This review summarizes the current knowledge concerning the molecular basis of Rh antigenicity, D-epitope expression, and the structures of the Rh genes and proteins. Although many recent reviews have appeared regarding these subjects, advances in Rh protein function that have been published within the last 12 months have had a fundamental impact on the future direction of Rh research. In November 2000, an article described the role of Rh proteins in ammonium transport, which has remained undescribed in vertebrates, except for non-specific transport via K+ channels. The recent identification of nonerythroid Rh proteins, their expression in diverse tissues, and notably polarized epithelial and endothelial cells will be of broad functional significance and will greatly increase our understanding of the role of Rh in ammonium transport and the biology of ammonium metabolism as a whole. The advances in Rh molecular genetics have enabled the development of diagnostic tests in the clinic. At present, this is largely confined to the prenatal diagnosis of fetal blood group status in alloimmunized pregnancies, but could be extended to the noninvasive prenatal testing of all D-negative pregnant women and eventually, perhaps, to all patient and donor blood.

Animals↗
PubMed2004

Ethical issues in psychiatric genetics.

As knowledge grows regarding the genetic bases of psychiatric disorders, a variety of ethical issues will need to be confronted. Current evidence suggests that the etiology of most psychiatric disorders rests on a combination of multiple genes and environmental factors. As tests for the genes involved become more easily available, pressures will arise to use them for prenatal testing, screening of children and adults, selection of potential adoptees, and pre-marital screening. Common problems that will need to be addressed include popular misunderstanding of the consequences of possessing an affected allele, impact of knowledge of one's genetic make-up on one's sense of self, and the discriminatory use of genetic information to deny persons access to insurance and employment. Although most states have some legislation aimed at preventing discrimination, the laws' coverage is spotty and federal rules are lacking. Physicians may find that newly available genetic information creates new duties for them, including warning third parties who may share the patient's genetic endowment. And genetics research itself has raised questions about when to disclose information to subjects and their family members about the genes that are being studied, and how to define the subjects of the research when information is collected about family members other than the proband. Knowledge of these dilemmas is a first step to resolving them, something that the medical profession will need to attend to in the near-term. Neglect will lead others to set the rules that will control medical practice, including the practice of psychiatry, in the new world of genetic medicine.

Adoption↗
PubMed2003

Down syndrome: interaction between culture, demography, and biology in determining the prevalence of a genetic trait.

The incidence of Down syndrome (DS) at conception is highly dependent upon the maternal age distribution and age-specific pregnancy rates. Live-birth prevalence of DS reflects these factors and fetal deaths. Since the introduction of prenatal diagnosis in the early 1970s, the role of fetal deaths in the equation has increased. Between 1920 and the early 1980s, DS live-birth prevalence decreased in many populations due to declining fertility rates, particularly among older women. In the late-1970s the trend reversed, as the median age of populations and birth rates among older women steadily increased. This paper illustrates these interactions using data we have analyzed for New York State (NYS) and comparative data obtained from the literature. Between 1983 and 1997 DS live-birth prevalence in NYS remained stable at about 9.9 per 10,000 live births. The number of prenatal tests performed increased by 158%, and the number of DS fetuses detected prenatally more than quadrupled. Fertility rates of women aged 35-49 continued to increase. The proportion of DS cases born to these older mothers increased from 23% in 1985 to 43% in 1997. We estimated that without prenatal diagnosis, DS live-birth prevalence would have been 17.0 per 10,000 live births by 1995. Cultural factors influence demographic trends, birthing technologies, physician practices, and women's decision-making regarding prenatal screening and diagnosis for DS.

Adolescent↗
PubMed1996

Routine voluntary antepartum HIV antibody counseling and testing: a sound public health prevention strategy.

Routine voluntary antepartum HIV antibody counseling and testing are important HIV prevention strategies based on sound public health principles. The ultimate goal of this testing strategy is two-fold: identification of high-risk seronegative women for risk reduction counseling; and identification of HIV-infected parturients for counseling, prenatal care, and long-term medical management. To achieve these objectives, there must be nationwide implementation of the CDC HIV prenatal testing guidelines. Our challenge as healthcare providers is to ensure that all of our prenatal patients are afforded the opportunity to have HIV counseling and testing performed.

Anonymous Testing↗
PubMed2000

[Need of better knowledge of genetic tests among Norwegian physicians].

BACKGROUND: New predictive genetic tests are introduced in clinical work, and this means new tasks for the physician. MATERIAL AND METHODS: Every sixth member of the Norwegian Medical Association practising as a general practitioner, neurologist or psychiatrist (N = 732), were asked to answer a mailed, anonymous questionnaire about their attitudes to the new tasks. RESULTS: We obtained 451 (62%) answers. There were no significant differences between the various groups in the profession. So far, 54% had no patient in their practice who had taken a predictive genetic test. About two-thirds answered that the geneticist should inform about what is known about the consequences after a test result has been given. The general practitioner wants to do the follow-up. 97% of physicians think that the test result could lead to increased distress in various ways for the tested person or his/her family. Half of the physicians would advise taking a prenatal test if one of the parents had a known risk of an inherited disease and the foetus was at risk. Only 22% are in favour of abortion if the foetus has the gene in question. INTERPRETATION: The physicians (93%) do not think they have sufficient knowledge about predictive genetic tests to handle the information procedure on their own. They want courses in medical genetics, concise and relevant information from geneticists, and the possibility of consulting with specialists.

Clinical Competence↗
PubMed2003

Living with achondroplasia: attitudes toward population screening and correlation with quality of life.

OBJECTIVES: Since the discovery of the gene that causes achondroplasia, population-wide prenatal screening for this condition has become a possibility. This study sought to assess attitudes toward screening for achondroplasia and correlation with quality of life in a population of individuals affected with achondroplasia and first-degree relatives. METHODS: Surveys were collected from 189 individuals affected with achondroplasia and 136 average-statured first-degree relatives. RESULTS: While 87% of all respondents would support the use of prenatal screening by affected parents at risk of having a fetus with the homozygous, lethal form of achondroplasia, 29% would support general population prenatal screening for achondroplasia. Attitudes supporting general population screening were more likely to be held by those people with less education, who were affected with achondroplasia, who supported abortion, and who believed that achondroplasia is a serious condition without any accompanying advantages (p<0.01). Those respondents who felt positively toward offering the prenatal test for individuals at risk for homozygous achondroplasia were more likely to have lower mean quality of life scores and to support abortion in general (p<0.05). CONCLUSION: These data suggest that opinions about prenatal screening are heterogeneous within this study population and are related to individuals' experiences and perceptions of the condition. Future research is needed to assess attitudes toward population screening and quality of life in communities of individuals affected with genetic conditions, both to support policy decisions and to inform the education and counseling provided in the prenatal setting.

Achondroplasia↗
PubMed1993

Perception of predictive testing for Huntington's disease by young women: preferring uncertainty to certainty?

Opinions on the implications of predictive testing for Huntington's disease were evaluated in a group of 169 women (aged 21-35 years) with interest in psychosocial issues, but with no special pre-existing knowledge or training in genetics. Predictive testing for Huntington's disease (HD) is considered to be a test case for predictive testing for other late onset diseases, monogenic as well as multifactorial disorders. In the hypothetical situation of having a 50% risk for developing HD, about half of the group expressed interest in a predictive test. As to the question of giving results of predictive tests to third parties, the group would be very reluctant to inform the employer or the insurer, but not their own family. Prenatal testing for late onset diseases was considered acceptable by half of the women; only one quarter of the total group would terminate a pregnancy of a child that might develop a late onset disease. The assessment of attitudes towards predictive testing was carried out within the context of a global evaluation of perceived advantages and disadvantages of genetic counselling. The attitudes towards predictive testing were systematically associated with perceiving 'having more certainty about the future' as an advantage of genetic counselling and with rejecting 'knowing everything in advance' as a disadvantage.

Adult↗
PubMed1999

Predictive value of the triple screening test for the phenotype of Down syndrome.

Maternal serum alpha-fetoprotein (MSAFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3) are routinely measured in the second trimester ("triple" test) and combined with maternal age to evaluate risk for fetal Down syndrome. Triple test results and clinical findings were retrospectively reviewed for 30 newborns with Down syndrome to determine whether analyte values or second trimester risks for Down syndrome were more extreme in affected pregnancies where cardiac or other severe congenital malformations were present compared to those cases where major anatomical abnormalities were absent. Mean MS-AFP, uE3, maternal age, and second trimester Down syndrome risk were all similar in the two groups of pregnancies. However, hCG concentrations did appear to be higher in the group of Down syndrome pregnancies with anatomical anomalies (mean 1.74 MoM versus 1.19 MoM) (P<0.05). Overall, there was no significant difference in the incidence of major anomalies in patients with screen-positive test results versus those cases that were not identified by the triple test. Prenatal counseling should therefore reflect the general expectations of the Down syndrome phenotype that have been established from live-born infants with this disorder.

Abortion, Spontaneous↗
PubMedDate not supplied

Laboratory identification of erythroblastosis fetalis.

The clinical laboratory assumes the paramount role of supplying accurate data to the attending physician for the diagnosis, treatment and prevention of HDN. Maternal prenatal testing identifies patients at risk for Rh-HDN. The antibody titer is of primary value in assessing patients as candidates for amniocentesis. Amniotic fluid analyses provide an assessment of fetal prognosis in HDN and also an assessment of gestational age, lung maturity, and placental function. In severe HDN, amniotic fluid analysis can indicate the need for intrauterine transfusion. Postnatal laboratory studies can confirm the suspected diagnosis of HDN, identify those neonates at risk of developing kernicturus, and provide the physician with information pertaining to the treatment of HDN. Finally, prenatal and postnatal laboratory testing identifies those females eligible for Rh-immune globulin therapy to prevent HDN in subsequent pregnancies.

ABO Blood-Group System↗
PubMed1988

Development of a self-administered questionnaire to measure women's knowledge of prenatal screening and diagnostic tests.

A prerequisite to an informed decision to undergo any screening or diagnostic test is knowledge about such a test. This study describes the development of a self-administered questionnaire to measure knowledge of prenatal tests, for use in studies concerning the uptake of these tests. Both the reliability (internal and test-retest) and predictive validity are evaluated. Validity is assessed in two studies: first, comparison is made between three criterion groups (two with experience of pregnancy, one without); and second, scores on the questionnaire are compared before and after women have been provided with information about possible tests. The results show this to be both a reliable and valid measure of knowledge about prenatal tests. The results also highlight aspects of knowledge that are lacking. For example, a sizeable minority of women were uncertain or incorrect in identifying which tests they had undergone in a recent pregnancy.

Amniocentesis↗
PubMedDate not supplied

[Prenatal diagnosis of spinal muscular atrophy (SMA) -- indications, restrictions, interpretation of results].

INTRODUCTION: Proximal spinal muscular atrophy of childhood and adolescence (SMA) is a genetic autosomal recessive disease. Caused in 96.5% by deletion in the SMN1 gene. Owing to the homogeneity of the molecular defect. Secondary prophylaxis can readily be offered to families at risk of SMA. PATIENTS: Prenatal diagnosis of SMA was carried out in a group of 50 families. Which were divided into two subgroups: with high and relatively low genetic risk of SMA. In all, 55 prenatal tests were performed in the period 1998-2003. RESULTS: In the first group including 45 families at high genetic risk, 9 of the 50 tests were positive (18%). The diagnosis of SMA was tentative in 7 cases from this group and it was based only on the clinical picture (the affected children are not alive, therefore DNA samples are not available). Prenatal examination in 1 of these 7 families showed the SMA genotype. In the second subgroup including 5 families with relatively low genetic risk of SMA in none of the studies was there a biallelic deletion of exon 7 in the SMNI gene. Mainly parents of children with a severe form of SMA and having no healthy offspring asked for prenatal examination (73% of the families). CONCLUSIONS: Prenatal diagnosis could be offered to families even if the diagnosis of SMA was not genetically verified. The negative result should he then interpreted individually. Until the carrier test will not he introduced to routine procedures. prenatal diagnosis can be also offered to families at relatively low risk of SMA.

Adult↗
PubMed2002

[Second trimester sonographic screening for Down's syndrome and other chromosomal abnormalities].

AIM: To assess the effectiveness of second trimester sonographic screening for Down syndrome [DS] and other chromosomal abnormalities [ChrA]. MATERIALS AND METHODS: In 1157 singleton pregnancies (15-21 weeks of gestation), including 18 with ChrA (13-DS, 5-other) an expert level detailed sonographic study was performed. The following parameters were analyzed: incidence and type of abnormal sonographic findings in chromosomally normal and abnormal fetuses, sonographic screening sensitivity and specificity (for DS and for other ChrA), positive predictive value [PPV] for DS of the most frequent sonographic markers, negative predictive value [NPV] of the normal genetic sonogram. Data were compared to those for serum screening (results from our previous studies, including all the patients from the present study). RESULTS: 77.8% of all fetuses with chromosomal abnormalities were identified by ultrasound. The detection rate for DS fetuses (69.2%) was lower and for other aneupliodies (100%)--higher than the detection rate of serum screening. All fetuses with more than one marker were chromosomally abnormal. Increased nuchal fold thickness was highly sensitive for ChrA and also--for DS (66.7% and 60% respectively). The same referred to echogenic bowel (60% and 50% respectively). Pyelectasis was highly sensitive only for DS (23.5%) while shortened femur was not (2.9%). Increased nuchal fold thickness, echogenic bowel and pyelectasis had high individual PPV for fetal DS. It was higher than the PPV of the serum screening positive test result. The NPV of the normal genetic sonogram was lower than the NPV of the screen-negative result from the serum screening. CONCLUSIONS: Second trimester expert fetal sonography is highly specific screening test, but its DS sensitivity is comparatively low. An abnormal genetic sonogram might indicate invasive prenatal testing or may be used to modify DS serum screening risk.

Chromosome Aberrations↗
PubMed2006

A preliminary comparison of the hopes of researchers, clinicians, and families for the future ethical use of genetic findings on schizophrenia.

A written questionnaire about genetic testing was distributed to all registrants at The 2004 World Congress of Psychiatric Genetics, mailed to clinical psychiatrists obtained from a directory of clinicians practicing in New York City, and mailed to members of families who have multiple affected family members with schizophrenia. A total of 274 individuals responded (162 researchers, 64 clinicians, and 48 family members). This survey shows that the majority of family members who completed the questionnaire (83.3%) would want to be tested if a genetic test were to become available. Over half of the family members (56.2%) would want prenatal testing. Similarly, over half of the clinicians (56.3%) would recommend it, despite only 25% of the researchers reporting that it would be a future useful tool. All of the clinicians surveyed thought adoption agencies should inform families about a family history of schizophrenia, while only half of the researchers thought this should be done (51.9%). These differences in opinions between consumers, their clinicians, and researchers could be based on a lack of understanding of the amount of risk conferred to family members by reported gene variants. Providing public discussions for placing these risks in perspective should be the responsibility of researchers. Open public discussion of the ethical and social uses of the information gained from psychiatric genetic research and its limitations is encouraged.

Adult↗
PubMed2003

[Routine cytomegalovirus screening during pregnancy: is it worthwhile?].

The issue of routine antenatal screening for cytomegalovirus (CMV) infection raises a controversy in France. Supporters of a screening policy argue that this frequent congenital infection (about 1% of all newborns) is a known cause of neurological impairment or hearing loss, which could be prevented by the prenatal screening of the infection. However the majority of infected fetuses will be free of any symptom, and there is currently no reliable prognostic marker in the antenatal period. Moreover, no prenatal treatment has proven to be effective and safe. A screening strategy might lead to iatrogenic concerns, including parental anxiety, invasive prenatal testing, and terminations of pregnancies for unaffected fetuses. Based on current knowledge, routine antenatal screening of CMV infection during pregnancy cannot be recommended. Further research should focus on the development of a safe and effective prenatal treatment, and the development of better diagnostic tests.

Antibodies, Viral↗
PubMedDate not supplied

DNA-based genetic testing in fifty fragile X families.

During the past 4 years (1985-1989), we have analyzed 171 cases in 50 fragile X [fra(X)] families by DNA linkage methods. Most (140 cases; 81%) were for carrier detection, both female (98 cases; 57%) and male (41 cases; 24%). Women who were obligate carriers of the fra(X) mutation accounted for an additional 6 "prior-to-pregnancy" cases. Four pregnancies have subsequently occurred with 3 having been successfully monitored (one male, 2 females). One pregnancy miscarried early prior to testing. Prenatal diagnoses (26 cases; 15%) accounted for the remainder of cases (15 males, 11 females). These will be discussed in the companion paper by Shapiro et al. (Am J Med Genet, 1991). A diagnosis in the cytogenetically uninformative carrier cases was reached in greater than 75% of analyses with a panel of 5 probes: 3 proximal (F9, DXS105, DXS98) and 2 distal (F8, DSX52). Five additional probes, 3 proximal (DXS10, DSX51, DSX102) and 2 distal (DSX15, DXS33), were used in cases that were resistant to analysis with the standard panel. In 60% of cases, flanking markers were identified (proximal and distal). Given this panel, only 5% of cases did not have any informative markers identified. Thus, molecular methods can provide a useful adjunct to cytogenetic analysis in most situations. An unusual association between the rare allele (A1) of DXS10 with the X chromosome carrying the fra(X) mutation was observed. This occurred in both male and female carriers in the uppermost generation tested. The basis for this association is uncertain at the present time.

Alleles↗
PubMed2000

Clonal culture of fetal cells from maternal blood.

Successful isolation and genetic testing of fetal cells obtained from maternal blood could eliminate the risks associated with invasive prenatal testing. We used clonal in-vitro expansion of fetal haemopoietic cells and micromanipulation and fluorescent PCR of single colonies to obtain pure fetal colonies from peripheral blood of 12 healthy pregnant women. Of 2966 randomly selected colonies, 42 contained fetal and other cells and, for four women, two to four colonies each contained purely fetal cells. Detection of fetal cells has been hampered by rarity in maternal blood, but with our approach many cells are available for analysis.

Cells, Cultured↗
PubMed1995

The developmental implications of prenatal and/or postnatal crack cocaine exposure in preschool children: a preliminary report.

Previous studies examining the development of prenatally cocaine-exposed children through 3 years of age have found no significant differences between exposed and control groups. This study explored the developmental correlates of prenatal and/or postnatal crack cocaine exposure in children between 4 and 6 years of age. Three groups were studied: Group 1, 18 prenatally-exposed children whose mothers continue to use crack; Group II, 28 children without prenatal exposure whose mothers presently use crack; and Group III, 28 children whose mothers never used crack. Mothers were street-recruited and were comparable in race and socioeconomic status. The three groups of children did not differ on neurological gross motor and expressive language measures. However, prenatally exposed children performed significantly worse than others on receptive language and visual motor drawing tests. Prenatal crack exposure predicted poor visual motor performance even after control for intrauterine alcohol and marijuana exposure, age, birth weight, and duration of maternal crack use.

Child↗