Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Different degrees of severity of anemia are presented in three siblings with homozygous beta-thalassemia. II-1, the most severely affected one, is splenectomized and needs frequent blood transfusion, while II-4 has mild anemia and never receives transfusion. II-3 has moderate anemia and mild jaundice and hepatosplenomegaly. Restriction endonuclease DNA mapping revealed the alpha-thalassemia-2 genes in II-3 and II-4 and no alpha-thalassemia-2 haplotype in II-1. Furthermore, II-4, who is mildly affected, is homozygous for alpha-thalassemia-2 whereas II-3 is an alpha-thalassemia-2 heterozygote. These observations indicate that concomitant inheritance of alpha-thalassemia can decrease the severity of beta-thalassemia.
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PMID:Different severity of homozygous beta-thalassemia among siblings. 359 99

A Moroccan woman was investigated because of a typical beta-thalassemia trait associated with a low-percentage (11%) hemoglobin (Hb) variant. The beta-thalassemia trait was manifested by a microcytosis, a high HbA2 (above 6%), and an increase of the alpha/beta biosynthetic ratio (1.31). The variant was identified to HbS by amino acid analysis of the abnormal peptide (beta T1) and by DNA mapping with Sau I (Mst II) restriction endonuclease. No additional amino acid substitution was recorded in the beta s-chain. The reduction of beta-globin synthesis occurred exclusively at the expense of the beta s-chain. These results are consistent with the existence of a beta s mutation and a beta +-thalassemia in cis.
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PMID:Association in cis of beta +-thalassemia and hemoglobin S. 367 4

Utilizing restriction endonuclease mapping and blot hybridization, we have determined the arrangement of the alpha-globin genes in a Chinese family. The father and mother had no obvious alpha-thalassemia symptoms, but their twin daughters suffered from HbH disease. The gene analysis showed that the mother had three alpha-globin genes in one chromosome and no alpha-globin gene in the other (alpha alpha alpha/--), the father was a heterozygote of alpha-thal2 (alpha alpha/-alpha). Their twin daughters were double heterozygotes of alpha-thall and the rightward deletion genotype alpha-tha12 (--/-alpha).
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PMID:Triplicated alpha-globin gene loci in a Chinese family. 402 93

Members of a Black family from Georgia who were investigated for the first time in 1960 and several times thereafter were reinvestigated through DNA restriction endonuclease analyses and haplotyping, while the gamma chain heterogeneity of the Hb F was reevaluated using a newly developed HPLC procedure. Four different abnormalities were present. (a) Heterozygosity for G gamma A gamma-HPFH type II characterized by a large deletion involving the delta and beta globin genes with a 5' end within the psi beta gene. (b) Heterozygosity for an -epsilon-G gamma-G gamma-psi beta-delta-beta S-chromosome, thus carrying a beta S globin gene and two G gamma genes instead of one G gamma and one A gamma gene. (c) Heterozygosity for an -epsilon-G gamma-A gamma T-psi beta-delta-beta S-chromosome, carrying the beta S globin gene and an allele of the A gamma (or A gamma I) gene. These three chromosomes occurred in combination with each other, resulting in SS and S-HPFH conditions, and with a normal -epsilon-G gamma-A gamma-psi beta-delta-beta A-chromosome resulting in the HPFH and Hb S heterozygosities. The presence of the -G gamma-G gamma- and -G gamma-A gamma T-chromosomes in the one SS patient was responsible for the high G gamma value (average 75%), 25% A gamma T chain, and for the absence of the A gamma I chain. (d) An alpha-thalassemia-2 heterozygosity in one member.
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PMID:Hemoglobin abnormalities in a black family with HB S, hereditary persistence of HB F, and a gamma chain variant; a reevaluation through gene mapping. 608 52

Restriction endonuclease mapping defined a partial deletion of about 1.35 kb in the beta-globin gene of a black American patient with hemoglobin S-beta zero-thalassemia and in his uncle with a beta zero-thalassemia trait. The 5' endpoint of the deletion is about 600 bases upstream from the cap site, and the 3' endpoint lies within about 500 bases from the 5' splice junction of the second intervening sequence. The deletion is different from that of a previously reported Indian beta zero-thalassemia allele, where 0.6 kb is deleted at the 3' end of the beta-globin gene.
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PMID:Partial deletion of the 5' beta-globin gene region causes beta zero-thalassemia in members of an American black family. 608 38

Restriction endonuclease mapping of chromosomal DNA has been used to determine whether the alpha-globin gene deletion or non-deletion form of alpha-thalassemia is the underlying molecular defect in individuals of two unrelated German families with alpha-thalassemia syndromes. The obtained DNA pattern in all cases indicated loss of alpha-globin genes resulting in -alpha/alpha alpha, --/alpha alpha, and --/-alpha genotypes in alpha-thalassemia-2, alpha-thalassemia-1, and Hb H individuals respectively. The chromosomes showing loss of one alpha-globin gene in alpha-thalassemia-2 and Hb H disease were characterized by the so-called rightward deletion form exhibiting loss of a 3.7 kb DNA fragment in the alpha-gene cluster.
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PMID:Alpha-globin gene deletion causes alpha-thalassemia syndromes in two German families. 609 37

By restriction endonuclease mapping, gene cloning, and DNA sequencing we have determined the region of DNA that is deleted in a family with gamma delta beta-thalassemia. The deletion removes the linked epsilon, gamma-, and delta-globin structural genes and terminates within the coding portion of the beta-globin gene. Since the extent of DNA deletion in this family differs from that reported in another family, we conclude that gamma delta beta-thalassemia is heterogeneous at the molecular level.
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PMID:Heterogeneity of DNA deletion in gamma delta beta-thalassemia. 616 60

A 2-yr-old black girl presented with a thalassemic clinical picture and was found to have nearly 100% fetal hemoglobin in her red cells. Pedigree analysis indicated that she was a heterozygote for the hereditary persistence of fetal hemoglobin gene and for a beta O-thalassemia gene. A brother, who also had nearly 100% fetal hemoglobin in his red cells, manifested, in contrast to his sister, no anemia and only minimal splenomegaly. Examination of the family's alpha-globin loci using the restriction endonuclease Eco Rl demonstrated that the brother had a single alpha-locus deletion that he had inherited from his mother. The mild clinical manifestations of this boy are consistent with the often expressed view that excess alpha chains may contribute significantly to the hematologic manifestation of beta-thalassemia.
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PMID:The effect of alpha-thalassemia on the expression of the beta-thalassemia/HPFH heterozygote in a black family. 616 20

Twenty-six DNA samples from individuals either heterozygous or homozygous for beta thalassemia were analyzed by restriction endonuclease digestion, agarose gel electrophoresis, and Southern blot analysis to define DNA fragments containing portions or all of the beta globin gene. A total of twenty-seven genes affected by a beta thalassemia mutation and twenty-seven genes affected by a beta thalassemia mutation and twenty-two normal beta globin genes were examined in Italian, Greek, or Asian individuals. With all four restriction endonucleases used, the fragments generated from DNA of thalassemic individuals were identical to those found in DNA from normal. Thus, gross rearrangement or deletion within the genomic region containing the beta globin gene is not characteristic of mutations which cause a thalassemia. A third patient homozygous for pancellular hereditary persistence of fetal hemoglobin was shown to have complete deletion of the delta and beta globin genes.
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PMID:Analysis of globin gene structure in patients with beta thalassemia by restriction endonuclease mapping. 616 67

Individuals heterozygous for the Greek (A gamma) variant of hereditary persistence of fetal haemoglobin (HPFH) synthesize Hb F whose gamma-globin chains are predominantly of the A gamma type. DNA obtained from Greek HPFH heterozygotes was used to test for abnormalities in the organization of non alpha-globin genes. In addition, gamma- and beta-globin expression was studied in BFUe cultures. Restriction endonuclease mapping showed that the G gamma, delta and beta genes in cis to the Greek HPFH determinant are intact. Overproduction of gamma-globin chains synthesis was observed in the BFUe cultures. A significant portion of the gamma chain synthesis was of the G gamma type, suggesting that the G gamma genes cis and trans to the HPFH chromosome are active in culture. DNA mapping data indicate that in contrast to G gamma A gamma HPFH and the G gamma (delta beta) thalassaemia, the Greek (A gamma) HPFH is not due to a large deletion in the non-alpha globin gene region. It is possible that the anomaly may result either from a small deletion or point mutation which influences non alpha-globin transcription. The in vitro synthesis data suggest that the low level of G gamma-globin chain synthesis in vivo is not the result of transcriptional inactivation of the G gamma gene, since this gene appears to be expressed in erythroid cell cultures. We speculate that the genetic lesion in Greek (A gamma) HPFH is in regulatory sequences which control the level of G gamma and A gamma expression during development.
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PMID:Greek (A gamma) variant of hereditary persistence of fetal haemoglobin: globin gene organization and studies of expression of fetal haemoglobins in clonal erythroid cultures. 617 32


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