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PubMedDate not supplied

Thalassemia intermedia.

Thalassemia intermedia is a clinical definition applied to patients whose clinical phenotype is milder than that of thalassemia major. Criteria used to define thalassemia intermedia including age at presentation, hemoglobin or fetal hemoglobin levels and transfusion independence, are unsatisfactory. The possibility of typing the molecular defect allows a retrospective analysis of patients and offers a new tool for the diagnosis of thalassemia intermedia. Nevertheless, because of several factors that interact in the disease expression, the beta-genotype alone is not predictive of the phenotype in all cases. Although benign, the clinical course of thalassemia intermedia is characterized by several complications that can be prevented by an accurate follow-up. The conventional treatment of thalassemia intermedia remains controversial; it is hoped that recent advances in the pharmacological manipulation of hemoglobin switching will offer a therapeutic option in the future, at least to selected patients.

Heterozygote↗
PubMed1994

[Molecular screening and prenatal diagnosis of the deletional alpha-thalassemia by polymerase chain reaction amplification].

For the genetic counselling, 8,432 blood samples from Chinese couples were screened for detecting alpha-thalassemia in Guangzhou city. The positive diagnosis of 646 (7.66%) alpha-thalassemia patients was made. One hundred DNA random samples from the above positive cases were collected and were analysed by using polymerase chain reaction (PCR) to determine the genotype of alpha-thalassemia of Southeast Asian deletion(--SEA/). Of 100 alpha-thalassemia individuals screened for the (--SEA/) mutation, 99 (96 with alpha-thalassemia trait and 3 with hemoglobin H disease) were detected by the present method. This mutation was not found in the remaining one with alpha-thalassemia compound Hb Q. We also used this assay to analyse DNA samples from cord blood in 6 pregnancies at risk of Bart's hydrops fetalis, in 1 at risk of Hb H disease for prenatal diagnosis.

Female↗
PubMed1994

Thalassemia major in Connecticut: a 20-year study of changing age distribution and survival.

There has been a near doubling of the mean age (10.7 to 19.0 years) of Yale-New Haven Hospital patients with transfusion-dependent homozygous beta thalassemia between 1973 and 1994. This change is, in part, a result of improved transfusion procedures and effective chelation therapy with deferoxamine mesylate. A concomitant trend has been a decrease in the number of births of new cases resulting in fewer thalassemia major patients less than 10 years of age in 1985 and 1994 compared to a decade earlier. Identification of individuals at risk of having children with thalassemia major by extensive screening for heterozygous thalassemia and the availability of prenatal diagnosis may have contributed to this change. Thalassemia major has become a disease of adolescents and young adults. The increasing age has resulted in "new" issues in thalassemia major patients such as sexuality and marriage as well as economic problems involving health-care insurance and employment.

Adolescent↗
PubMed1993

Unbiased analysis of the frequency of beta-thalassemia point mutations in a population of African-American newborns.

OBJECTIVE: To determine frequency of specific beta-thalassemia alleles in the African-American population prospectively, using newborn screening specimens, and to evaluate the need for including these alleles in screening follow-up programs. DESIGN: Allele-specific oligonucleotide tests were developed and used to analyze African-American newborn screening specimens for beta-thalassemia point mutations to determine their frequency. Direct sequencing of amplified DNA from the dried blood specimens was used to confirm the presence of point mutations. POPULATION: African-American newborns in Texas. RESULTS: Allele-specific oligonucleotides identified five newborn specimens carrying beta-thalassemia point mutations among 471 specimens from African-American neonates. Direct sequencing of DNA from the dried blood specimens confirmed that these individuals had a normal and a mutant allele. Five newborn screening specimens in which the results of screening and DNA tests were in disagreement (four with FS by screening and AS by DNA, and one with FC by screening and AC by DNA) were analyzed for these beta-thalassemia point mutations and in each case were found to be S/beta-thalassemia or C/beta-thalassemia compound heterozygotes, respectively. CONCLUSIONS: Allele-specific oligonucleotides accurately identified newborn specimens carrying beta-thalassemia point mutations. Direct sequencing from dried blood specimens confirmed these results. The A(-29)G allele frequency was 0.003, and the C(-88)T frequency was 0.002. These alleles also were observed among positive samples in a neonatal hemoglobinopathy screening program. Therefore, any newborn screening program with a molecular genetic follow-up component must include testing for these beta-thalassemia alleles to assure timely and appropriate management for affected infants.

Alleles↗
PubMed1993

Bone marrow transplantation for thalassemia in Thailand.

We report our experience of bone marrow transplantation for thalassemia in Thailand. From July 1988 to September 1992, 10 thalassemic patients underwent allogeneic bone marrow transplantation. Two of them were homozygous beta-thalassemia and 8 were beta-thalassemia/Hb E disease. Seven were male and 3 female. The age ranged from 1.8-14 years. The conditioning regimen comprised busulfan 14 mg/kg and cyclophosphamide 200 mg/kg. For GVHD prophylaxis, either cyclosporine alone or in combination with short methotrexate was given. Five patients were alive and well 104-1534 days after transplantation. Three patients with severe manifestations at the time of transplant had partial engraftment, and lost their graft within 3 months. They survived with thalassemia 1041-1357 days after transplantation. One patient who received one antigen mismatched marrow from her brother had no engraftment and was alive with thalassemia 1429 days posttransplant. One patient died early on day 9 from CNS complication. No GVHD was observed in this series. These results indicate that bone marrow transplantation can cure thalassemia but there is still high autologous recovery rate in those with severe manifestations.

Adolescent↗
PubMed1995

Clinical phenotypes and genotypes diagnosis of thalassemia in children.

Thalassemia is a relatively common hemolytic anemia in Southeast Asia. Alpha and beta thalassemia, hemoglobin (Hb) E, and Hb Constant Spring (CS) are prevalent in Thailand. Different gene combinations lead to over 60 thalassemic syndromes. One hundred and forty-nine thalassemia families were retrospectively studied. They were 4 homozygous beta-thalassemia (beta-thal/ beta-thal), 79 beta-thal/Hb E, 22 Hb H disease, 32 Hb with Hb CS, and 6 AE Bart's disease. The first clinical manifestation and hematologic data including hemoglobin electrophoresis were analysed. Most homozygous beta-thalassemia and beta-thal/Hb E presented with anemia (100% vs 81%), hepatomegaly (40% vs 21%), and splenomegaly (20% vs 27%). In Hb H disease and Hb H with Hb CS, the clinical findings were anemia (74% vs 79%), hepatomegaly (9% vs 8%), splenomegaly (9% vs 13%), jaundice (24% vs 13%), and fever (18% vs 25%). The 317 hematologic data and hemoglobin types of the patients, their parents and relative were also analyzed. These findings can be used as reference values for childhood thalassemia and heterozygous states.

Adolescent↗
PubMed1996

Prevalence of scoliosis in beta-thalassemia.

The objective of this study was to determine the prevalence and possible pathogenesis of scoliosis in beta-thalassemia in our country, and to compare its characteristics to those of patients with idiopathic scoliosis from the same geographic area. Twenty-four [13 male and 11 female thalassemic patients aged 16 +/- 7 years (range 7-32 years)] of 115 examined patients with beta-thalassemia showed scoliosis of 14 degrees +/- 11 (range 10-65 degrees) radiologically. The prevalence of scoliosis in the thalassemic population was 21% in this series, whereas the overall prevalence of scoliosis in the general Greek population was 6% (Smyrnis PN, Valavanis J, Alexopoulos A, Siderakis G, Giannestras NJ: School screening for scoliosis in Athens, J Bone Joint Surg 61B:215-217, 1979). The scoliosis prevalence in the general population was significantly higher in the females (5%) than in the males (1%), whereas no difference in prevalence was found between the two sexes in the thalassemic population. The most common curve pattern in thalassemia was the left lumbar (38%) followed by the right lumbar (21%), whereas in patients with idiopathic scoliosis the left thoracolumbar most commonly appeared (25%) followed by the left lumbar (14%). No patient with thalassemia showed radiographic signs of congenital spinal deformities and spinal fractures, whereas all patients showed a significant retardation of their skeletal maturation. The age of the thalassemic patients with scoliosis was significantly (p = 0.0003) higher than in patients without scoliosis. The hematocrit of the thalassemic patients with scoliosis was significantly (p = 0.0012) lower than in those without scoliosis, whereas the rate of transfusions was not correlated with the magnitude of the scoliosis. The level of ferritin was significantly (p = 0.025) higher in the thalassemic patients with scoliosis than in those without scoliosis. The duration of Desferal treatment was significantly (p = 0.0357) longer in thalassemic patients with scoliosis when compared with those without scoliosis. Thus, the prevalence, curve pattern, and etiology of scoliosis in beta-thalassemia differ from those of idiopathic scoliosis, indicating that the spinal deformities in thalassemia represent a distinct type of scoliosis.

Adolescent↗
PubMedDate not supplied

[Beta-thalassemia and glucose-6-phosphate dehydrogenase deficiency].

Twenty subjects--patients with anemia and their close relatives representing 7 families, were tested for thalassemia. Heterozygotic beta-thalassemia was detected in 17 cases. The national composition of this patient population was as follows: 7 Pathans (Afghanistan), 1 family; 2 Armenians (Georgia), mother and son; 2 Tajiks, sibs; 2 patients of mixed Russian-Ukrainian-Polish-Azerbaijan origin, mother and son; 1 Russian-Arab child and his Arab father (Syria); 1 Uzbek woman and 1 Russian child. The mean content of Hb in the blood for patients with heterozygotic beta-thalassemia is 110 +/- 3.8 g/liter, that of HbA2 fraction 4.8 +/- 0.26% and of HbF fraction 2.6 +/- 0.39%. Clinical manifestations of the disease varied, being more grave in children than in adults. In an Armenian family from Batumi thalassemia minor was diagnosed in the mother and son, whereas in the father and other son a periodic disease was revealed. In a family of 7 members from Afghanistan thalassemia minor was found in 4 representing the paternal line, minimal thalassemia was suspected in 3, and a deficiency of glucose-6-phosphate dehydrogenase in red blood cells was revealed in 5: in the mother and 4 children. No increase of methemoglobin level was revealed in either of the examinees.

Adolescent↗
PubMed1996

[Rapid prenatal diagnosis of 60 cases with beta-thalassemia by reverse dot blot analysis].

OBJECTIVE: To evaluate the rapid prenatal diagnosis method for beta-thalassemia by reverse dot blot (RDB) analysis. METHODS: Using RDB analysis which can detect 18 types of beta-thalassemia mutation, 60 fetuses (with 1 twin) suspected of beta-thalassemia from 59 couples in Southern China were investigated. RESULTS: 15 fetus had normal genotype, 34 were carriers of heterozygous with one of parental affected gene; 10 had both parental affected genes-heterozygous or homozygous; and 1 was not able to identified. Three rare types of beta-thalassemia mutations (CD43, CD14-15, CD27-28) were detected. CONCLUSIONS: The RDB assay is able to complete the screening of beta-thalassemia mutation by DNA hybridization in only one single working day. It is simple, accurate and convenient to operate without radio-isotopes. It can be used as a routine technique in clinical laboratory for the detection of carriers and prenatal diagnosis of beta-thalassemia.

Adult↗
PubMed1998

Red blood cell phenotypes in alpha-thalassemias in the Spanish population.

BACKGROUND AND OBJECTIVE: alpha-thalassemia is very common on all thalassemic geographical regions. The present work aimed at analyzing the relationship between the degree of microcytosis and hematological parameters and the type of alpha-thalassemic mutation. DESIGN AND METHODS: Five hundred and thirty-six subjects with 4 kinds of alpha-thalassemia were examined using established techniques that determined all hematological parameters, and globin synthesis and molecular biological techniques to study the DNA of globin genes by Southern blotting. RESULTS: Adult carriers of alpha (+)-thalassemia (-alpha/alpha alpha) present very few hematological alterations. In a statistical comparison with normal individuals (alpha alpha/alpha alpha), significant differences were found between the hemocytometric data and the MCV and MCH of heterozygous alpha + thalassemia and the heterozygous alpha zero or homozygous alpha + genotype. Hb H disease was detected in 15 patients, presenting a severe degree of anemia, a significant increase in RDW and globin chain synthesis with an alpha/beta ratio of 0.5 +/- 0.1. INTERPRETATION AND CONCLUSIONS: These data provide reference values for geographical areas where alpha + thalassemia is common. These hematocytometric data, together with hemoglobin analysis, could be useful as a future reference data for new patients diagnosed with alpha-thalassemia.

Adolescent↗
PubMedDate not supplied

[Abnormal hemoglobins and thalassemias in Mexico].

The distribution of abnormal hemoglobins in Mexico is derived from surveys and from the study of patients with hemolytic anemia. In aboriginal populations, more than 3,000 individuals have been studied: structural abnormal hemoglobins are virtually absent in Mexican Indians and the sporadic finding of hemoglobin S among them is due to admixture with Africans brought as slaves during the Spanish domination; two new variants of hemoglobin (Mexico and Chiapas) were found in aborigines. The surveys in hybrid groups in selected areas of the country show that in some West and East Coast communities there are different frequencies of Hb S heterozygous, and that a high prevalence of Hb S trait has been found in some communities similar to that in some African areas. In a group of 200 subjects of a town located along the Gulf of Mexico Coast, 6% of Hb S and 15% of thalassemia beta heterozygous is observed. In hospital surveys in two cities (Guadalajara and Puebla) several abnormalities of hemoglobin have been identified (C, SC, Riyadh, Baltimore, Tarrant, Fannin-Lubbock and Mexico). In the study of isolated cases, mainly of patients with hemolytic anemia, hemoglobins I-Philadelphia, G-San Jose and D-Los Angeles are seen. The thalassemias are the more frequent hemoglobin abnormalities in selected populations of our country. In a community of Italian ancestry a frequency of 1.3% of beta thalassemia trait is found. In our laboratory, 76% of the abnormalities are cases of beta thalassemia trait. Patients with Hb H disease, beta thalassemia (homozygous and heterozygous) and combinations of these abnormalities with hemoglobins S, Hb S + hereditary persistence of fetal hemoglobin (HPFH) and Hb E as well as families with delta-beta thalassemia, HPFH and Hb Lepore-Washington-Boston have been also detected.

Hemoglobins, Abnormal↗
PubMed1996

Elevated zinc protoporphyrin associated with thalassemia trait and hemoglobin E.

OBJECTIVE: Increased zinc protoporphyrin/heme (ZPP/H) ratio has been used in pediatrics to screen for iron deficiency and lead poisoning. This study was conducted to determine whether common hereditary hemoglobin disorders (alpha- and beta-thalassemia traits, hemoglobin E) found in U.S. minority groups are associated with an increase in the ZPP/H ratio in an iron-sufficient population. METHODS: The database was compiled from hemoglobinopathy screens performed between 1987 and 1993 at a regional referral laboratory in Washington State. ZPP/H ratio and hemoglobin type were obtained for 326 subjects between the ages of 15 and 49 years of age who were iron sufficient (serum ferritin levels > or = 50 micrograms/L). RESULTS: The mean ZPP/H ratio was significantly higher (p < 0.01) for subjects with beta-thalassemia trait (87 +/- 32 micromol/mol), (alpha-thalassemia trait (73 +/- 37 micromol/mol), and hemoglobin E disorders (73 +/- 24 micromol/mol) than for subjects with normal hemoglobin values (60 +/- 8 micromol/mol). Fifty-one percent of subjects with beta-thalassemia trait, 22% with hemoglobin E, and 20% with alpha-thalassemia trait had elevated ZPP/H ratios (> 80 micromol/mol), compared with only 1.5% with normal hemoglobin values. CONCLUSIONS: The ZPP/H ratio is elevated in common hereditary hemoglobin disorders that mimic the microcytic anemia of iron deficiency, even in individuals without associated nutritional iron deficiency. For children who are treated for presumed iron deficiency, failure of the ZPP/H ratio to return to normal after adequate iron treatment, especially if microcytosis persists, indicates that a hereditary hemoglobin disorder may be present.

Adolescent↗
PubMed1998

Combined use of erythrocyte zinc protoporphyrin and mean corpuscular volume in differentiation of thalassemia from iron deficiency anemia.

In a retrospective study the diagnostic value of erythrocyte zinc protoporphyrin (ZPP) measurement as a means of distinguishing iron deficiency anemia from thalassemia syndromes in patients with microcytosis was explored. ZPP values were increased in all patients with iron deficiency and in part of the patients with thalassemia. The combined measurement of erythrocyte mean corpuscular volume (MCV) and ZPP resulted in a correct classification of patients with iron deficiency and with thalassemia in more than 95%. The predictive value of this method is better than the results obtained by using formulae derived from red cell indices. In population screening programs for thalassemia syndromes, in which MCV determination is used as the initial test, the ZPP test is recommended as a second test, in order to discriminate between patients with microcytosis due to iron deficiency and patients with microcytosis due to thalassemia syndromes.

Adult↗
PubMed1992

Biophysical changes of red cells with thalassemia-like abnormal hemoglobin.

Hemoglobin (Hb) E and Hb Constant Spring (CS) are known to have thalassemia-like effects. Investigation on the red cell physical changes in these two abnormalities has been done to clarify the diversity of red cell changes between thalassemia and thalassemia-like abnormal hemoglobin (Hb E represents beta-thalassemia and Hb CS represents alpha-thalassemia). Eleven cases with homozygous Hb CS (CS/CS), 7 homozygous Hb E subjects (E/E) and one double heterozygous case with Hb CS and Hb E were included in this study. The red cells were analyzed by the H* 1 hematology analyzer. The E/E red cells had significantly smaller MCV than the CS/CS red cells (p < 0.001). The smaller MCV of E/E red cells was attributed to markedly increased percent microcyte (p < 0.001) and significantly lower percent macrocyte (p < 0.001) as compared to CS/CS red cells. Degree of heterogeneity in cell volume as indicated by red cell distribution width (RDW) was not significantly different between the two abnormal hemoglobin containing red cells. It was also noted that the CS/CS cases had a more significant increase in small RBC than the E/E cases (p < 0.001). Significant lower intraerythrocyte hemoglobin concentration values of the CS/CS red cells as compared to E/E red cells were shown: cellular hemoglobin concentration mean (CHCM) (p < 0.001), percent hyperchromic red cell (p < 0.001) and hemoglobin distribution width (HDW) (p = 0.0367). Higher values for the CS/CS red cells were MCH (p < 0.001) and percent hypochromic red cells (p < 0.001). Red cells from both genotypes had significant decreases in red cell deformability.(ABSTRACT TRUNCATED AT 250 WORDS)

Biophysical Phenomena↗
PubMed1992

Does Hakka ethnic group have higher incidence of thalassemia traits in Taiwanese population?

The purpose of this survey is to find out whether Hakka group has higher incidence of thalassemia traits in our population. A total of 1,115 healthy employees from a company were screened by complete blood count (CBC) with indices. Those subjects with mean corpuscular volume (MCV) less than 80 fl were further evaluated by hemoglobin electrophoresis and modified hemoglobin H (Hb H) inclusion staining to confirm the diagnosis of beta- and alpha-thalassemia traits, respectively. We evaluated and compared the crude occurrence rates of thalassemia traits in Hakka, non-Hakka, and Taiwanese. Subjects with one or both Hakka parents had higher crude incidence of alpha-thalassemia traits than other groups of subjects, but this phenomenon wasn't found in beta-thalassemia traits.

Adult↗
PubMed2004

Molecular basis and hematologic characterization of deltabeta-thalassemia and hereditary persistence of fetal hemoglobin in Thailand.

BACKGROUND AND OBJECTIVES: Hereditary persistence of fetal hemoglobin (HPFH) and deltabeta-thalassemia are heterogeneous disorders characterized by increased levels of Hb F in adult life. The distinction between these two conditions is not always possible from routine hematologic analyses. This study investigated the hematologic and molecular characteristics of high HbF determinants in Thailand, and describes a rapid DNA-based assay to facilitate diagnosis in a routine laboratory. DESIGN AND METHODS: A multiplex allele-specific polymerase chain reaction (PCR) system for rapid detection of three common DNA deletions causing (deltabeta)0-thalassemia and HPFH in South-east Asians was developed and used to examine the molecular basis for the high Hb F phenotypes in 273 unrelated Thai individuals. Hematologic data were recorded and correlated to the molecular findings. RESULTS: The multiplex PCR system was validated and results were completely concordant with those of other established methods. DNA analysis identified GgAg(deltabeta)0-thalassemia in 148 cases (54.2%), deletional HPFH-6 in 83 (30.4 %) and the deletion-inversion Ggamma(Agammadeltabeta)0-thalassemia in 22 (8.1 %) cases, while another 20 (7.3 %) subjects remained uncharacterized. Genotype-phenotype relationships are discussed. INTERPRETATION AND CONCLUSIONS: These data emphasize the high frequencies of deltabeta-thalassemia and HPFH in Thailand and the need for differential diagnostic methods since the hematologic parameters associated with the conditions are very similar and overlap. The multiplex allele-specific PCR approach should prove useful in complementing routine Hb analysis for the differential diagnosis of these three common causes of high Hb F determinants and should facilitate a program of hemoglobinopathy screening in the region.

Adolescent↗
PubMedDate not supplied

[Molecular aspects of alpha dn beta thalassemias].

Thalassemia has been considered a recessive, autosomic, hereditary disease, characterized by microcytic, hypochromic, hemolytic anemia, which occurs as the consequence of a defect in the synthesis of the globin chains, the two most frequent types are thalassemias a and b, which in their most severe forms are known as Hydrops Fetalis and Major Thalassemia. The patients who bear thalassemia are concentrated to those places on earth where malaria is endemic, including the Mediterranean region, Northern Africa, The Middle East, India, China and Southern Asia. The simple Heterozygotic states in both types of thalassemia are more benign and may go unnoticed or confused with iron deficiency.

Base Sequence↗
PubMed1995

[Thalassemia].

Gene analysis of thalassemia started more than 10 years ago. The analysis has been considerably facilitated by the advent of PCR. There are over 20 kinds of mutations in Japanese beta-thalassemia known to date, among which 8 mutations comprise 75% of all families with beta-thalassemia. Several simplified methods are available for these "common" mutations. Here, are introduced two simple methods; amplification refractory mutation system(ARMS) and gap PCR for analyses of beta-thalassemia(one-point mutation) and alpha-thalassemia(large DNA deletion), respectively. These methods are easily applicable to routine DNA analysis.

DNA↗