Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019045 (hemoglobinopathies)
 2,704 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. In a review of methods developed for the identification of fetal malformations, the technique, risks and results of amniocentesis are presented. 2. Large series already published have demonstrated the relative simplicity and feasibility of the procedure as well as current indications for its utilization. These include the detection of chromosomal anomalies, the determination of sex (in certain sex-linked disorders), documentation of enzymatic and metabolic deficiencies, and the demonstration of open lesions of the neural tube by appropriate techniques. 3. Experience with over 500 cases personally tested by the authors entirely confirms the major indications for and benefits of this modern method for the detection and prevention of severe congenital anomalies during early pregnancy. 4. The identification of chromosomal alterations is currently the major objective of the method. Increased risks are associated with pregnancies involving a maternal age of 35 years or older (which account for 1-3% of aneuploidies), the birth of a previous infant with free trisomy 21 (1% recurrence risk) or secondary to a parental chromosome translocation (as much as 10% risk of aneuploidy). Fetal karyotyping for determination of sex, in cases where the mother is a carrier of an X-linked recessive gene (on average, 50% of male offspring will be affected), is an inadequate method of diagnosis to be utilized only until alternative techniques render possible specific diagnosis of the anomalies under consideration (hemophilias A and B, muscular dystrophy, etc). 5. Several of these techniques are now nearing development through the advent of fetoscopy and advanced ultrasound methodology, and have already been applied to the detection of certain sex-linked disorders and also for diagnosis of hemoglobinopathies (thalassemias, sickel cell anemia) and other conditions requiring the obtaining of fetal blood for diagnosis. Technology allowing direct examination of fetal parts by means of optical instruments is particularly useful in cases where a severe fetal morphologic malformation cannot currently be identified by indirect visualization (ultrasound) or by analysis of cytogenetic or molecular markers. 6. Pathological accumulations of alpha-fetoprotein which are associated with diverse feto-placental abnormalities (particularly open malformations of the neural tube) can be detected in the amniotic fluid and/or maternal blood. In extension of this approach, it is foreseeable that conditions existing prenatally will be diagnosed in a growing number of cases from the study of fetal cells and molecules which can be isolated from the venous blood of pregnant women. This will become feasible as a result of some well-developed techniques which allow separation of fetal from maternal cells and metabolites, and also to some extremely fine analytic techniques, notably examination of the DNA itself by means of restriction enzymes.
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PMID:[Prenatal diagnosis. Review, personal and prospective studies]. 8 63

New reproductive genetics means recently developed techniques to prevent the birth of children with specific defects or genetic diseases by testing individuals for sickle cell anemia, the thalassemias, Tay-Sachs disease, cystic fibrosis, or Down syndrome. Third World health services have many deficiencies with high maternal mortality rates (30-40 fold higher than in developed countries), the low percentage of births delivered by health personnel, the high rates of low birth weight babies, and high child malnutrition and infant mortality rates. The main issues in women's reproductive health are fertility regulation, abortion, maternal mortality, sexually transmitted diseases, and infertility. As a result of expansion in contraceptive use worldwide, the total fertility rate in developing countries has declined from 6.1 in 1965 to 3.9 in 1990. It is estimated that, worldwide, 36-53 million induced abortions are performed each year, most of them in developing nations. WHO estimates that more than 500,000 women die each year because of complications of pregnancy, most in developing countries. More than 95% of the 13 million estimated deaths of children under 5 years of age have occurred in these countries. Approximately 200 million people carry a potentially pathologic hemoglobinopathy gene, and about 250,000 children are born every year with hemoglobinopathy, most of them in the developing world. Reproductive genetic testing in big cities and in private for-profit ventures cater to the socioeconomic elite. Amniocentesis is often misused for fetal sex determination to abort female fetuses in India. Currently, in Cuba virtually every pregnant woman is tested for sickle cell trait and maternal serum alpha-fetoprotein levels between 15 and 20 weeks of gestation. It is predicted that the judicious use of reproductive genetic testing will be possible when health and quality of life issues are addressed properly.
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PMID:Reproductive health and genetic testing in the Third World. 840