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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

At this time a rather large number of congenital abnormalities still occur. About 2-3% of pregnancies will result in children with major congenital abnormalities that cannot be detected prenatally. Yet, with the availability of prenatal diagnosis for an ever increasing number of genetic problems and, more recently, for developmental problems as well, a new option was offered to couples at risk when they took the risk of pregnancy: finding out whether the fetus was abnormal. An early argument regarding the ethics of this option was formulated by Dan Callahan, director of the Hastings Institute for Ethics, Society and the Life Sciences, when he indicated the need to be careful about the term "option." A need exists to be careful about societal pressures in favor of the new medical options--on, for example, a pregnant woman who is over 35 and does not get a prenatal diagnosis; or on a woman carrying a Down's syndrome child identified by prenatal diagnosis not to have an abortion. This was the 1st specter raised when prenatal diagnosis was introduced. The most common indication for amniocentesis is the risk of chromosomal abnormalities. The risk of discovering a chromosomal abnormality by amniocentesis is about double the risk at birth because a number of chromosomally abnormal fetuses are lost late in the 2nd trimester by spontaneous abortion. The age cutoff at 35 raises an immediate ethical question: since the total number of births to women over age 35 seems to be increasing, and at the same time a greater and greater percentage of children with Down's syndrome are born to women under age 35, the question arises as to whether amniocentesis should be done on all pregnancies, and whether all births with Down's syndrome should be selectively aborted or avoided. Amniocentesis in all pregnancies is impractical at this time from the technological and the cost perspective, but the ethical question should be raised. Among the X-linked disorders, 1 group cannot be specifically diagnosed in utero by prenatal diagnosis. If a woman is known to be a carrier, her daughters won't have the disease, but half of them will be carriers. Regarding sex preference as a reason for amniocentesis, all the geneticist can and should do is provide a couple with a base of knowledge and understanding of the options available to them and the outcome of each option. X-linked disorders such as hemophilia and Lesch-Nyhan syndrome and the autosomal recessive biochemical disorders or inborn errors of metabolism such as Tay-Sachs disease and over 100 others can now be diagnosed prenatally. In the vast majority of cases, amniocentesis is performed because the parents already have an abnormal child. Screening programs for Tay-Sachs disease, for sickle cell anemia, and for thalassemia also detect couples at risk. A variety of tools other than amniocentesis are now available for prenatal diagnosis. Much work is being conducted in the prenatal diagnosis of sickle cell anemia and thalassemia.
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PMID:Genetics, amniocentesis, and abortion. 660 72

Owing to the fact that Germany has become the domicile of a great number of aliens from Mediterranean countries, an increasing number of thalassaemia cases have been reported and given cause for a thorough investigation. Since thalassaemia minor is a hereditary disease, a special prophylaxis has to take place in case of pregnancy: 1. examination of child's generator, 2. genetic counselling, 3. embryoscopy and extraction of embryonic blood, 4. if thalassaemia is diagnosed, an abortion should be taken into consideration.
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PMID:[Management of pregnant women with thalassemia minor]. 685 40

The results of 200 antenatal diagnoses in pregnancies at risk for homozygous beta-thalassaemia, carried out on fetal blood samples obtained by placental aspiration in the second trimester, are described. Globin chain synthesis in the fetuses was measured by means of 3H-leucine incorporation and separation of the chains on carboxy-methyl-cellulose columns. Fetal red cell enrichment was performed by NH4Cl-NH4HCO3 differential lysis of maternal cells or anti-i differential agglutination. Sufficient fetal blood for analysis was obtained in 97.5% of the cases. The overall fetal loss rate was 6.5%, but it declined from 10% in the first consecutive 100 cases to 3% in the last 100 cases. Fetal loss was the result of early or late intrauterine death or spontaneous abortion. Forty-two homozygous fetuses had no beta-chain synthesis and one had a very low beta/gamma ratio (0.005). Of the pregnancies, 37 were terminated at parental request and four aborted spontaneously. Absence of beta-chain radioactivity was confirmed in 12 abortuses with suitable cord blood samples for analysis. Two pregnancies with homozygous fetuses were not terminated, as one member of each couple was a devout Catholic. As expected, both infants developed Cooley's anaemia. Follow-up of the 146 infants, diagnosed in utero as non-homozygotes, showed cerebral palsy in one and a small cutaneous needle injury in three. None of these developed homozygous beta-thalassaemia. Even beta-thalassaemia trait with a beta/gamma ratio of 0.046 +/- 0.012 can be distinguished from normal, showing a beta/gamma ratio of 0.086 +/- 0.019 with a high degree of certainty.
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PMID:Haematological and obstetric aspects of antenatal diagnosis of beta-thalassaemia: experience with 200 cases. 707 30

Detailed follow-up is presented of 335 pregnancies in which mid-trimester fetal blood sampling was performed for the diagnosis of a haemoglobinopathy, mostly beta-thalassemia. There were three twin pregnancies. Thirty-eight fetuses were lost including four in whom a diagnosis of thalassemia major was made. Placentacentesis was particularly associated with fetal vessel trauma, exsanguination and early intrauterine fetal death, while late complications associated with fetoscopy or failed fetoscopy necessitating subsequent placentacentesis included spontaneous abortion, leakage of amniotic fluid and premature onset of labour.
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PMID:Obstetric outcome and problems of mid-trimester fetal blood sampling for antenatal diagnosis. 729 95

The thalassaemias are genetic syndromes brought about by a low or nil synthesis of one or more of the main globinic chains and by consequent imbalance of the normal ratio between alpha and non-alpha chains. Three basic pictures can be distinguished: (1) microcythemia or thalassaemia minima, the expression of heterozygosis for one microcythemic gene, which includes beta, delta beta and alpha microcythemias. Subjects are healthy but very often pale and asthenic, (2) intermediate thalassaemia, very similar to thalassaemia major, though a less severe disease. It is the expression of the presence of microythemic geness which results in a globin synthesis imbalance less marked than that of the thalassaemia major. The patients are frankly anemic and more or less pronounced hyperhemolysis (but they only need sporadic transfusions, usually at adult age), and present splenomegaly often of a considerable extent and hepatomegaly. Their physical growth and reproductive capacity are normal or nearly so and they attain the fifth or sixth decade of life. Two varieties of this syndrome have been identified, namely beta-intermediate thalassaemias (or Rietti-Greppi-Micheli's disease or also constitutional microcythemic anemia) and alpha-intermediate thalassaemias (or Hb H disease); (3) thalassaemia major or Cooley's anemia or Mediterranean anemia, the expression of homozygosis for severe genes of microcythemia which results in a marked globin synthesis imbalance; this is a so severe disease that not treated patients usually die when they are three-four years old. Nowadays, however, prognosis, clinical course and life expectancy of these patients are considerably improved so that they usually attain the third decade of age in relatively fair conditions. There are available three fundamental therapeutic actions: blood transfusions carried out at very short intervals; splenectomy which allows to reduce the rhythm of the blood transfusion regimen; the iron chelating therapy which delays the onset of the iron overloading in the organism. Finally, it is possible the prevention of this disease by preventing the procreation between microcythemics and by prenatal identification of Cooley's foetuses followed by thier selective abortion.
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PMID:[Clinical aspects of thalassemia (or microcythemia)]. 730 Nov 67

Antenatal diagnosis was carried out in a pregnancy at risk for beta-thalassaemia major/intermedia, resulting from the Lepore/ beta-thalassaemia genotype, by globin chain synthesis analysis on fetal blood obtained by placentocentesis at 19 weeks' gestation. As there was no radioactive incorporation in the beta-region, the fetus was considered to be a Lepore/ beta-thalassaemia genetic compound and aborted on parental request. After abortion, cord blood analysis confirmed the absence of beta-chain radioactivity.
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PMID:Prenatal diagnosis of thalassaemia major resulting from Lepore/ beta-thalassaemia genotype. 733 11

Prenatal diagnosis with globin chain synthesis analysis on fetal red blood cells concentrated by NH4Cl-NH4HCO3 differential lysis of maternal cells (Orskov lysis) was carried out in 27 pregnancies at risk for beta thalassaemia and one at risk for sickle cell beta0 thalassaemia. The beta/gamma globin chain synthesis ratio was also determined after anti-i-differential agglutination (12 cases), in almost pure fetal samples (sic cases) and by extrapolation (one case). Differential lysis permitted the study of samples drawn by placental aspiration containing as little as 3.2% fetal red blood cells. There was no consistent difference between the beta/gamma ratios observed after differentail lysis and those determined after the use of the other approaches. A presumptive diagnosis of homozygous beta thalassaemia was made in nine cases. All but one of these pregnancies was terminated. The absence of beta chain synthesis was confirmed by the study of fetal blood after abortion in four cases with suitable samples. Of the remaining pregnancies, six proceeded to term and non-homozygous infants were delivered. The others are still in progress. No fetal loss occurred. Orskov lysis seems to be a very reliable method for prenatal diagnosis of beta chain abnormalities. Moreover it can minimize the number and duration of placental aspirations required and thus the risk to the fetus.
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PMID:Prenatal diagnosis of beta thalassaemia by fetal red cell enrichment with NH4-Cl-NH4HCO3 differential lysis of maternal cells. 737 9

Prenatal diagnosis of beta-thalassemia can be performed by chorionic villus sampling as early as the ninth gestational week, and early amniocentesis within 12 weeks of gestation. Selective abortion or termination should be suggested if the fetus is affected. With polymerase chain reaction (PCR) and micromanipulation techniques, the preimplantation diagnosis of beta-thalassemia has become possible. A total of 60 single blastomeres were collected and equally divided at random into two groups. Eight DNA primers (A to H) were designed for 15 mutations of beta-thalassemia in Chinese people. Two beta-globin gene fragments (602 bp and 423 bp) were amplified by PCR through two sequential reactions with two sets of primers (A+B and C+D, E+F and G+H), respectively. The amplified products were confirmed by Southern blotting with DNA probes hybridization. The amplification rates were 54% (16/30) and 60% (18/30), respectively. All of the positive and negative controls showed the presence or absence of amplification, respectively. Our study provides a possible approach for the preimplantation diagnosis of beta-thalassemia.
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PMID:Amplification of beta-globin gene from single blastomeres. 792 58

The aim of this study was to ascertain the degree of acceptability of preimplantation diagnosis with blastocentesis in 180 women at risk for beta-thalassaemia awaiting chorionic villus sampling (CVS). The women were asked to fill in a questionnaire some days before sampling. All women who had had previous therapeutic abortion found blastocentesis acceptable. Only 30% of women who had not had previous therapeutic abortion chose blastocentesis, whilst 25% of primigravid women opted for blastocentesis. From these preliminary data it seems that obstetric experience is an important factor in the reproductive choice of women at high genetic risk.
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PMID:Psychological implications and acceptability of preimplantation diagnosis. 802 97

There is a lack of information on the use of contraceptives among women with sickle cell disease in the United Kingdom, and 150 babies are born with sickle cell disease every year. This study examines the questionnaire responses of 156 women who had sickle cell disease and were known to the hematology departments and sickle cell centers in north London. 42 of the women had sickle cell hemoglobin C disease; 12 women had sickle thalassemia disease, and 102 had homozygous sickle cell disease. 149 were sexually active. The mean age was 28.4 years. 100 of the women had 207 pregnancies of which 133 were unplanned. 25 women with 31 pregnancies miscarried. 31 women (39 pregnancies) terminated the pregnancies for social or medical reasons. 4 (3 with homozygous sickle cell disease and 1 with sickle cell thalassemia) of the 67 women, who used combined oral contraceptives, reported increased crises, and 2 women, with homozygous sickle cell disease, reported deep vein thrombosis. 54 of the 148 sexually active patients had been counseled not to get pregnant. Only 3 women said this advice influenced their plans. There were only 44 women (28%) who adequately understood the inheritance patterns of sickle cell disease although 94 (60%) knew about the possibility of prenatal diagnosis. Many factors affect decision- making including a poor obstetric history and rejection of abortion on moral grounds. 45% have used oral contraceptives at one time or another and 19% used the intrauterine device. This is similar to use patterns in North America. The medical community may to blame for the inadequate use of contraceptives, because of not knowing which contraceptives to recommend in these cases. There are no contraindications to prevent sickle-cell women from using oral contraceptives.
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PMID:Contraceptives, counselling, and pregnancy in women with sickle cell disease. 840 Sep 60


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