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PubMed1989

Beta-cluster haplotypes, alpha-gene status, and hematological data from SS, SC, and S-beta-thalassemia patients in southern California.

The beta-gene-cluster haplotype and alpha-gene status were determined for 221 patients with sickle cell anemia, 41 with SC disease, and 21 with S-beta-thalassemia. Among SS patients, eleven beta S haplotypes were found in 21 combinations. Three haplotypes--the Benin (Ben) [---+-], the Central African Republic (CAR) [+---+], and the Senegal (Sen) [+- ]--comprise 61%, 21%, and 10% of the chromosomes, respectively. Cleavage at the Xmn I site 5' to the G gamma gene was observed only when the Senegalese arrangement was present. The linear correlation which exists between the absolute value of the G gamma chains and the Hb F for each haplotype combination suggests a feed-back mechanism which controls the G gamma to A gamma ratio and thus the Hb F level (or vice versa). The A gamma T chain was present with specific haplotypes [++-++] and [++-+-]. Heterozygous or homozygous alpha-thalassemia-2 was present in 36% of the SS patients and was randomly distributed among beta S-gene-cluster haplotypes. The variable levels of hemoglobin, MCV, Hb F, G gamma chains, and Hb A2 are in response to the heterogeneous genetic mix of the beta S-gene-cluster haplotypes and alpha-thalassemia-2 in American patients with sickle cell anemia. The influence of alpha-thalassemia-2 on the level of Hb F is dependent on the beta S-cluster haplotype. Hb A2 levels increased with decrease in the number of alpha genes. Among SC and S-beta-thalassemia patients the beta-cluster polymorphisms on the beta S chromosome were those commonly associated with the African origins of beta S haplotype. The haplotype [+--+-] was present on the C chromosome in 90% of the cases. Most beta-thalassemia chromosomes had haplotypes that matched the common African polymorphisms. An alpha-gene deletion was found in 29% of the SC and S-beta-thalassemia patients.

Adolescent↗
PubMed2000

An algorithm to aid in the investigation of thalassemia trait in multicultural populations.

CONTEXT: The differentiation between iron deficiency and a thalassemia syndrome is an important consideration in the investigation of microcytic anemia. OBJECTIVE: An established statistical method was used to demonstrate the importance of considering ethnic background in combination with mean cell volume (MCV) in the investigation of beta-thalassemia trait in a multicultural urban population. DESIGN: Posttest probabilities for beta-thalassemia trait were calculated using likelihood ratios for various microcytic MCV ranges in conjunction with published pretest probabilities for beta-thalassemia trait based on ethnic background. SETTING: Regional hemoglobinopathy laboratory, St Joseph's Hospital, Hamilton, Ontario, Canada. PATIENTS: Patient data were derived from a previously published study. The original study cohort consisted of 789 patients aged 18 years or older who had an MCV less than 80 fL and were referred for routine complete blood count during a 6-month period. MAIN OUTCOME MEASURES: Posttest probabilities. RESULTS: Simplified tables for the determination of posttest probabilities for beta-thalassemia trait in individual patients based on ethnic background and MCV are provided. An algorithm to assist in determining when thalassemia investigations are indicated is presented. CONCLUSIONS: A high index of suspicion based on ethnic background and low MCV can provide increased sensitivity and specificity for the detection of thalassemia trait in centers with multicultural populations similar to the study population.

Algorithms↗
PubMed1999

[Molecular genetics of the thalassemias in Argentina].

PURPOSE: Was to establish the molecular genetics of thalassemias in Argentina. PATIENTS AND METHODS: Genomic DNA was amplified by PCR and six point mutations in the beta-globin gene were investigated by Dot Blot hybridization using oligonucleotide probes. The most frequent alpha-thalassemia deletions were studied by Southern Blotting. Patients were distributed in 4 groups: a) 109 beta-thalassemic carriers; b) 15 thalassemia major patients; c) 2 thalassemia intermedia patients and d) 14 probable alpha-thalassemic carriers. RESULTS: The distribution of mutated alleles in the group a) was: IVS-1 nt 1: 13.76%, IVS-1 nt 6: 7.34%, IVS-1 nt 110: 23.85%, codon 39: 39.45%, IVS-2 nt 1: 3.68% e IVS-2 nt 745: 1.83%, 10.01% could not be determined with the probes used; in the group b) the allelic distribution was similar and the compound genetic genotype were predominant related to homocygous ones; in the group c): we confirmed the presence of one beta-thalassemia mutation and a alpha gene triplication (alpha alpha alpha) in the 2 patients studied. The alpha-thalassemia character was confirmed in 8 patients of the group d) (6 had -alpha 3,7/alpha alpha genotype and 2,-alpha 3,7/-alpha 3,7 genotype). CONCLUSIONS: This study indicates that the analysis of 6 mutations in the beta-globin gene and the alpha-globin gene deletions are an effective strategy to identify thalassemias in Argentina.

Alleles↗
PubMed2001

Effect of antioxidant flavonoids and a food mutagen on lymphocytes of a thalassemia patient without chelation therapy in the Comet assay.

Thalassemia remains a significant health problem in Europe, the Middle East, and Asia. In such patients, generally high iron levels make free oxygen radicals accessible, for example, through Fenton-type chemistry, and generate superoxide and hydroxyl radicals. Increased oxygen radical capacity is known to be associated with cancer and ageing. It was shown in previous studies that peripheral blood lymphocytes from a sickle/beta thal double heterozygote-sickle phenotype, thalassemia patient, not yet on chelation therapy, were more sensitive to the effects of oxygen radicals and iron salts than lymphocytes from normal controls. Iron overload in thalassemia patients can result from dietary absorption. It was considered that with other dietary agents, such as food mutagens and flavonoids, the thalassemia patient might also show increased sensitivity to the effects of these agents. The present study, therefore, compared the effects of the food mutagen/carcinogen, 3-amino-1-methyl-5H-pyrido(4,3-b)indole (Trp-P-2), in fresh or frozen normal human peripheral lymphocytes with frozen lymphocytes from the same thalassemia patient. The lymphocytes from the thalassemia patient showed an approximately two-fold increase in sensitivity. When a combination of Tryp-P-2, with either quercitin or kaempferol, was compared in frozen lymphocytes and lymphocytes from the thalassemia patient, a two-fold increase in sensitivity was also maintained. Responses to Trp-P-2 were reduced to untreated control levels at the highest doses of quercitin and kaempferol, and were highly significantly different by comparison with Trp-P-2 alone (P<0.001). The flavonoids acted in an antigenotoxic/antioxidant manner. Sensitivity was slightly increased with kaempferol by comparison with quercitin. At low concentrations of the flavonoids there was some evidence of an exacerbation of response, perhaps due to a switch to pro-oxidant status. This exacerbation of response at low doses of flavonoids has been seen in earlier studies with normal lymphocytes. Teratogenesis Carcinog. Mutagen. 21:165-174, 2001.

Carbolines↗
PubMed2000

Prevention and control of thalassemia in Ramathibodi Hospital, Thailand.

Eight thousand seven hundred and thirty-six pregnant women were screened for thalassemia and hemoglobinopathies by mean corpuscular volume less than 80 femtolitres (fl). Three thousand six hundred and seventy women (42%) were MCV less than 80 fl. In this group there were 2,390 women (70%) who had positive Hb typing by high performance liquid chromatography (HPLC) such as beta-thalassemia major, beta-thalassemia hemoglobin E disease, beta-thalassemia trait, heterozygous and homozygous hemoglobin E, alpha-thalassemia-1 trait and hemoglobin H disease and 77% of their partners came and had hemoglobin typing done. Seventy-five couples at risk for having severely affected thalassemia fetuses were detected from this screening program. Prenatal diagnosis was performed in 58 couples (77.3%). Eight affected fetuses were detected. All pregnancies with affected fetuses except one with beta-thalassemia/HbE were terminated. There were 3 fetal losses (6%) as the result of prenatal diagnosis procedure.

Chromatography, High Pressure Liquid↗
PubMed2001

[Beta-thalassemia: clinical manifestations].

Monogenic diseases are very unevenly distributed throughout the world and beta-thalassemies are due chiefly to a large number of point mutations of the beta globine gene. The thalassemia trait (heterozygous thalassemia) can be asymptomatic and diagnosis is established by demonstration of an increased proportion of Hb A2. In the homozygous state (thalassemia major) hypochromic anemia is extremely severe because erythropoiesis is largely ineffective. Regular transfusion is necessary to prevent early death and transfusion therapy is usually initiated in the first year of life after biological diagnosis. Iron chelation is now capable of preventing transfusional haemachromatosis responsible for late mortality. 10% only of patients with homozygous beta-thalassemia have a syndrome of intermediate haematologic severity (thalassemia intermedia). Hb S--beta-thalassemia disease is characterised by a clinical course that resembles more that of Sickle Cell disease than to the thalassemia syndromes.

Blood Transfusion↗
PubMed2003

Prenatal diagnosis of alpha-thalassemia of Southeast Asian deletion with non-radioactive southern hybridization.

BACKGROUND: Alpha-thalassemia is a common hereditary disease in Taiwan. Affected patients always carry a heavy burden of morbidity and early death. Prenatal diagnosis has reduced the disease burden on families and the health care system. This study evaluated a new non-radioactive Southern blotting hybridization method for prenatal diagnosis of this disease. METHODS: Seventy two chorionic villi samples (CVS) and 30 amniocyte samples from 102 pregnancies of couples who were both heterozygous for alpha-thalassemia-1 of the Southeast Asian (SEA) type deletion were studied. A non-radioactive Southern blotting hybridization method using a dig-alkaline phosphate detection system was developed for use in this study. RESULTS: Non-radioactive Southern blotting hybridization data showed that 19 (26%) CVS and five (17%) amniotic fluid samples had 10 Kb and 4Kb fragments, indicating homozygosity of the alpha-thalassemia-1 SEA type deletion. DNA samples were extracted from most of the aborted tissue of the 24 fetuses with a diagnosis of homozygous for the alpha-thalassemia-1 SEA type deletion. Homozygosity for alpha-thalassemia-1 SEA type deletion was reconfirmed by Southern blotting hybridization in all of these samples. CONCLUSIONS: The non-radioactive Southern hybridization protocol used in this study allows efficient and accurate early prenatal diagnosis of alpha-thalassemia-1 SEA type deletion. It can be routinely used for testing couples who both carry the alpha-thalassemia-1 SEA type deletion.

Adolescent↗
PubMed1976

Decreased alpha globine mRNA in nucleated red cell precursors in alpha thalassemia.

The alpha thalassemias are associated with a decrease in alpha chain synthesis. Hemoglobin H (HbH) disease is a moderately severe form of alpha thalassemia characterized by the production of 5%--20% of HbH, while alpha thalassemia trait is a milder form of alpha thalassemia. In two patients with HbH disease, the ratio of alpha chain synthesis to beta chain synthesis (alpha/beta ratio) was decreased in both bone marrow cells and reticulocytes. When isolated mRNA from bone marrow cells and reticulocytes was translated in a heterologous cell-free system, the alpha/beta ratios were lower than the intact cell ratios. These findings were confirmed by hybridization of the mRNA of both marrow cells and reticulocytes using purified alpha and beta cDNA probes. In the intact cells of two patients with alpha thalassemia trait, the alpha/beta ratios were also decreased and were similar in marrow cells and reticulocytes. Cell-free studies of translatable mRNA also demonstrated decreased alpha/beta ratios, but, unlike the HbH studies, the cell-free alpha/beta ratios were similar to the intact cell ratios. One hybridization study utilizing peripheral blood mRNA had an alpha/beta ratio consistent with the cell-free ratios. These results indicated that, in both HbH disease and alpha thalassemia trait, there was decreased alpha globin mRNA present in both nucleated red cell precursors and reticulocytes. In addition, the data suggested that there may be translational mechanisms that operate in intact HbH cells which attempt to balance globin chain production. In alpha thalassemia trait cells, no such controls appeared to be active and globin chain synthesis was directly proportional to the amount of alpha and beta globin mRNA in the cells.

Adult↗
PubMed1992

Rapid detection of Spanish (delta beta)zero-thalassemia deletion by polymerase chain reaction.

delta beta-Thalassemia and hereditary persistence of fetal hemoglobin (HPFH) are inherited disorders characterized by the persistent synthesis of fetal hemoglobin (HbF) during adult life. The Spanish type of delta beta-thalassemia is a mild thalassemic condition due to a large deletion starting at the Alu I repeat between the A gamma and delta-globin genes immediately 3' to the RIH probe and extending 11 and 17 kb downstream of the 3' endpoints of HPFH 1 and HPFH 2, respectively. Using probes from the Spanish (delta beta)zero-thalassemic DNA, the 3' breakpoint region has been mapped to a point approximately 8.5 to 9.0 kb downstream from that of HPFH type 1 and, as we know the restriction sites 3' to this breakpoint, the presence of the deletion can be identified with the polymerase chain reaction (PCR). In the present study, a PCR method using three specific oligonucleotides has been developed for the identification of the Spanish (delta beta)zero-thalassemia in 100 patients with delta beta-thalassemia (99 heterozygotes with mild anemia, decreased mean corpuscular volume, and 5% to 15% HbF, and one homozygote with 100% HbF and thalassemia intermedia phenotype). We conclude that the finding of the Spanish type of (delta beta)zero-thalassemia in all the patients studied here suggests Spain as the most probable origin of this thalassemic phenotype. Moreover, the amplification of the fragment encompassing the deletion junction and normal sequence is useful for the rapid molecular detection of Spanish (delta beta)zero-thalassemia.

Base Sequence↗
PubMed2005

[Umbilical cord blood transplantation for patients with beta-thalassemia major].

OBJECTIVE: The beta-thalassemia major is a common hereditary hematology disease in southern China. The combination of blood transfusion and iron chelation is now the reference treatment. The allogeneic hematopoietic stem cell transplantation is the only curative therapy for beta-thalassemia major. In this study the investigators observed and evaluated the effects of umbilical cord blood transplantation (UCBT) for patients with beta-thalassemia major. METHODS: Twelve cases of beta-thalassemia major aged from 1.3 to 8.3 years (8 male and 4 female) received UCBT. Eleven of the twelve donors were siblings and one was unrelative. Eight patients received no antigen and four patients received two antigen disparate grafts. According to the Pesaro's classification for thalassemia, 10 patients were at grade I or II, and 2 were at grade III. The HLA-identical patients accepted the conditioning regimen consisting of busulfan, cyclophosphamide and antithymocyteglobulin. The HLA-mismatched patients accepted the conditioning regimen consisting of hypertransfusions, continuous iv desferrioxamine, hydroxyurea, fludarabine, busulfan, cyclophosphamide and antithymocyteglobulin. The harvest stem cells contained 3.63 - 16.0 x 10(7)/kg of nucleated cells, 0.11 - 1.03 x 10(6)/kg of CD(34)(+) cells and 0.17 - 1.18 x 10(5)/kg of colony-forming-unit-granulocyte macrophages. Cyclosporine alone or in combination with mycophenolate mofetil (MMF) was given for acute graft-versus-host disease (aGVHD) prophylaxis. RESULTS: Of the 12 patients, 10 were engrafted. Ten patients had neutrophil recovery (> 0.5 x 10(9)/L) and seven patients had platelet recovery (> 50 x 10(9)/L). The median time was 18.1 and 57.3 days, respectively. Seven patients had disease-free survival (DFS) at a median follow up of 23 months (range 4 - 63 months). Three patients had rejection and autologous hematopoitic reconstitution. Two patients were not engrafted. One patient acquired severe aplastic anemia, another patient died of severe infection. The incidences of grade I and grade II aGVHD were 60% (6/10) and 40% (4/10), respectively. There were no long-term complications in the disease free survivors. CONCLUSIONS: Grade I-II beta-thalassemia major patients receiving sibling UCBT had high DFS. UCBT is an effective way to treat beta-thalassemia major.

Child↗
PubMed1992

Dominant thalassemia-like phenotypes associated with mutations in exon 3 of the beta-globin gene.

Mutations producing beta-thalassemia reach individual gene frequencies greater than .01 in malarial-endemic regions because beta-thalassemia trait individuals have increased genetic fitness over that of normal individuals. Exon 3 of the beta-globin gene has been relatively spared as a site of common beta-thalassemia mutations. Frameshifts caused by the loss of a single nucleotide and nonsense mutations produce beta-thalassemia trait when they occur in exons 1 and 2. In contrast, they usually produce chronic hemolytic anemia when present in exon 3. Certain missense mutations in exon 3 produce unstable globins and thalassemia intermedia with hemolysis in heterozygotes. Here we report two new mutations in exon 3 of the beta-globin gene. One is a single nucleotide deletion in codon 109 in a 78-year-old Lithuanian with chronic hemolytic anemia and features of thalassemia. It leads to an abnormal globin (beta Manhattan) that is elongated to 156 amino acids. The second is a CAG-CGG missense mutation at codon 127 that causes a Gln----Pro substitution (beta Houston) and a thalassemia intermedia with hemolysis in three generations of a British-American family. Although the clinical phenotypes of these two patients differed little, differences in globin-synthetic ratios were significant, presumably reflecting differences in the ability of each abnormal beta-globin to form alpha beta dimers. The paucity of high-frequency exon 3 mutations and their worldwide distribution is likely attributable to their phenotypic severity and loss of increased genetic fitness vis-a-vis malaria.

Aged↗
PubMed2005

Clinical phenotypes and molecular diagnosis in a hitherto interaction of Hb E/beta thalassemia syndrome (beta(E)/beta(-31), (A -->G)).

Molecular identification of affected alleles in the index family with rare mutation(s) and/or interaction(s) is an important prerequisite toward a proper genetic counseling. In Thailand, where more than 30% of the populations are heterozygotes for either alpha or beta thalassemia mutation(s). More than 60 different thalassemia syndromes resulting from the interactions of these heterogeneous alleles have been observed. The majority of patients in the hospital based-study are compound heterozygotes for beta thalassemia alleles and another hemoglobinopathy namely Hb E, highly prevalent in Thailand, gave rise to Hb E/beta thalassemia syndrome. The phenotypes of these syndromes vary from asymptomatic individual to a very severe phenotype mimic that of beta thalassemia major. In this report, we describe a three-year-old Thai girl presenting with mild hypochromic microcytic anemia since birth. She was born prematurely and developed anemia within the first week of life. The cause of anemia was suspected to result from prematurity and low intrauterine iron storage, however hypochromic anemia did not resolve after a three-month of iron supplement therapy. Subsequent studies indicated that the patient had Hb E/beta thalassemia disease and the molecular study revealed that the patient was a compound heterozygote for Hb E and a rare beta thalassemia mutation (beta(-31), A --> G). This hitherto genotype results in a relatively mild clinical symptom since the patient's baseline Hb values were around 9-10 g/dL with normal weight and height development during the follow-up period.

Beta-Globulins↗
PubMed2006

Result of video-education on "genetic transmission in thalassemia" to thalassemic patients and their parents.

OBJECTIVE: To determine the degree of knowledge improvement and retention after a single viewing of a video CD presentation on the genetic transmission of thalassemia among patients with thalassemia and their parents. MATERIAL AND METHOD: The present research was approved by Khon Kaen University Ethics Review Board A video CD on the genetic transmission of thalassemia was created as an educational tool for improving knowledge and retention. The validity and the informative usefulness of the video CD was evaluated, adapted and approved by a thalassemia expert. Between November 1, 2002 and September 30, 2005, 61 subjects (thalassemic patients and their parents, both groups were in reproductively active ages) at the Pediatric Outpatient Unit, Srinagarind Hospital, Khon Kaen, consented to participate. Their ages ranged between 17 and 50 years (mean +/-SD = 36.5 +/- 9.4; median = 38.0) and 44.3% completed elementary while 26.2% completed secondary school. Their occupations varied. Mothers, fathers, and thalassemic patients comprised 68.9%, 21.3%, and 9.8% of participants, respectively. In a quiet room in the Unit, each subject watched a single viewing of the video. A validated questionnaire (Cronbach's alpha coefficient = 0.79) with 40 true/false items was used to evaluate baseline knowledge on the genetic transmission of thalassemia. Knowledge was retested four times: immediately after the viewing, then at the 4th, 12th, and 24th week. The scores for each test were skewed toward high scores; therefore, non-parametric tests were used for the statistical evaluation. RESULTS: The running time for the video CD was 20 minutes. The baseline knowledge on genetic transmission was high. Immediately after a single viewing of the video, the knowledge level increased significantly (p = 0.000, 95% CI = 4.0-7.0) and was maintained up to the 12th week, after which (at the 24'h week) there was a significant drop (p = 0.020, 95% CI = -2.0 to 0) compared to the immediate post-test. CONCLUSION: The authors' video CD presentation effectively provided knowledge on the genetic transmission of thalassemia to patients with thalassemia and their parents. Post-viewing knowledge increased significantly and was retained for at least 12 weeks. Thereafter a refresher should be taken.

Adolescent↗
PubMed2003

Study of serum zinc in relation to nutritional status among thalassemia patients in Damanhour Medical National Institute.

Thalassemia results from an imbalance between two proteins in hemoglobin called alpha and beta globin that interferes with cell maturation and function resulting in an ineffective erythropoeisis and hemolysis. Zinc is an essential element that supports normal growth and development. In thalassemia, the expected low serum zinc level is due to hemolysis, loss in urine and inadequate dietary intake. To evaluate serum zinc levels among thalassemia patients and study its relation to nutritional status and growth, a case control study was conducted at Damanhour Medical National Institute. Forty-six thalassemia patients were randomly selected from the attendants of the Hematology Unit and were compared to 20 control children. They were subjected to medical history and examination, anthropometric measurements, assessment of dietary profile, laboratory investigations for CBC, total serum protein, serum albumin, serum zinc. The mean age was 8.29 +/- 3.96 years for cases and 8.45 +/- 3.52 years for controls. Thalassemia patients showed significant lower serum zinc level when compared to and 8.45 +/- 3.52 years for controls. Thalassemia patients showed significant lower serum zinc level when compared to control (88.28 +/- 17.76 microg/dl), and (113.5 +/- 15.39 microg/dl) respectively A positive correlation was found between their serum level and height/age (r = 0.392). Zinc supplementation and nutrition education program are recommended to improve growth rate among thalassemia patients with retarded growth ad low serum zinc levels.

Body Height↗
PubMed1992

Molecular characterization of beta-thalassemia in the Sardinian population.

This study reports the molecular characterization of beta-thalassemia in the Sardinian population. Three thousand beta-thalassemia chromosomes from prospective parents presenting at the genetic service were initially analyzed by dot blot analysis with oligonucleotide probes complementary to the most common beta-thalassemia mutations in the Mediterranean at-risk populations. the mutations which remained uncharacterized by this approach were defined by denaturing gradient gel electrophoresis (DGGE) followed by direct sequence analysis on amplified DNA. We reconfirmed that the predominant mutation in the Sardinian population is the codon 39 nonsense mutation, which accounts for 95.7% of the beta-thalassemia chromosomes. The other two relatively common mutations are frameshifts at codon 6 (2.1%) and at codon 76 (0.7%), relatively uncommon in other Mediterranean-origin populations. In this study we have detected a novel beta-thalassemia mutation, i.e., a frameshift at codon 1, in three beta-thalassemia chromosomes. The DGGE procedure followed by direct sequencing on amplified DNA is a powerful approach for the characterization of unknown mutations in this genetic system. The results herein presented allowed an expansion of the applicability of prenatal diagnosis by DNA analysis, to all couples at risk for beta-thalassemia in our population.

Base Sequence↗
PubMed1991

Prenatal diagnosis of thalassemia and hemoglobinopathies in Thailand: experience from 100 pregnancies.

In this review, we describe a simple strategy to detect the three severe thalassemic diseases commonly found in Thailand. Hb Bart's hydrops fetalis can be detected unambiguously by ultrasonography at 18-20 weeks of gestation or detected early in the first trimester by the gene amplification technique. Prenatal diagnosis for homozygous beta-thalassemia is better performed in the second trimester by in vitro protein synthesis. This is because the molecular defects of some beta-thalassemias are still unknown and homozygosity of the same mutation is low. In contrast, beta-thalassemia/Hb E is easily detected, in the first trimester, by direct visualization on electrophoresis or by dot blot analysis of enzymatically amplified DNA with a set of nonradioactively labeled oligonucleotide probes complementary to the most common mutations. We also found that the beta/gamma synthesis ratio in homozygous Hb E is similar to that of beta-thalassemia/Hb E and DNA analysis is the only method to distinguish these two conditions in the couple at risk of having either beta-thalassemia/Hb E or asymptomatic homozygous Hb E. In 100 pregnancies studied, the diagnoses were achieved in 96 pregnancies. Complications leading to fetal loss were found in 3 pregnancies: one woman developed amnionitis after fetal blood sampling; one had amniotic fluid leakage after the biopsy, and the third, carrying a normal fetus, aborted 10 days after fetal blood sampling with urinary tract infection and high fever. However, these figures are compatible with other reports and the risks are significantly lower than that of thalassemic disease the fetus is facing. One case of beta-thalassemia/Hb E was incorrectly diagnosed prenatally as being Hb E trait. In twenty-five pregnancies (25%) prenatally diagnosed to carry affected fetuses it was decided to have abortion. This study shows the feasibility of prenatal diagnosis for thalassemic diseases in Thailand which, in addition to screening and genetic counseling, can support prevention and control programs for thalassemia.

Female↗
PubMedDate not supplied

Iron stores and iron deficiency anemia in children heterozygous for beta-thalassemia.

This paper describes the status of iron stores, the incidence and the hematological characteristics of iron deficiency anemia in children heterozygous for beta-thalassemia. In beta-thalassemia heterozygotes, iron stores were similar to the controls in infancy and tended to increase with age, reaching levels of moderate iron overload solely in adult males. Iron deficiency anemia occurred less frequently in children heterozygous for beta-thalassemia as compared to normal controls, while no difference between the two groups was observed in the incidence of iron deficiency. Ineffective erythropoiesis, typical of heterozygous beta-thalassemia, by causing an increase of iron absorption may limit the effect of iron shortage. At similar levels of iron depletion, however, children heterozygous for beta-thalassemia develop a more severe anemia as compared to non beta-thalassemic children. With the exception of two children, HbA2 levels in the presence of iron deficiency anemia remain in the range of heterozygous beta-thalassemia. In conclusion, our results indicate that children heterozygous for beta-thalassemia have normal iron stores but are relatively protected against the development of iron deficiency. When iron deficiency anemia develops, its clinical expression is usually more severe than in non beta-thalassemic children.

Anemia, Hypochromic↗
PubMed1986

A novel basis for delta beta-thalassemia in a Chinese family.

We have studied a Chinese family in which beta-thalassemia and delta beta-thalassemia were found in simple and compound heterozygous states. The delta beta-thalassemia heterozygote (the mother) had 22.3% hemoglobin F, of which 40% was G gamma and 60% A gamma; globin chain studies showed an alpha/beta + gamma ratio of 1.36. The compound heterozygote for delta beta-thalassemia and beta-thalassemia (the child) had the clinical picture of thalassemia intermedia and an alpha/beta + gamma ratio of 4.44. Gene mapping studies were performed using DNA from the affected child. Seventy kilobases of DNA in the beta-globin gene cluster starting upstream from the epsilon-globin gene and ending downstream from the beta-globin gene were mapped, and no detectable deletions or rearrangements were detected. In addition, heterozygosity was detected at multiple polymorphic restriction sites in and 3' to the beta-globin gene, which excludes the possibility of a deletion of the entire beta-globin gene cluster. This is the first example of a nondeletion delta beta-thalassemia associated with increased expression of both G gamma and A gamma genes.

Female↗