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C Altay

Publications and source records attributed to C Altay.

At least 73 records · Page 4Linked to original sources
PubMed1988

Mild and severe beta-thalassemia among homozygotes from Turkey: identification of the types by hybridization of amplified DNA with synthetic probes.

Through the procedure of gene amplification combined with hybridization to synthetic 19 base pair (bp) oligonucleotide probes, it has been possible to identify nine different mutations in the DNA of 47 subjects from Turkey and Northern Cyprus with a beta-thalassemia homozygosity. The IVS-I nucleotide (nt) 110 G----A and the IVS-I nt 6 T----C substitutions and the frameshift at codon 8 were most frequently observed. Direct correlations were made between these data and clinical observations; mild disease was associated with homozygosity for IVS-I nt 6 T----C, for frameshift at codon 8, for the C----G substitution at nt -87, and for IVS-I nt 5 G----T, and for a double heterozygosity for some of these conditions. Moderate disease, observed in some of the patients, could be explained by combinations of specific mutations. All mutations were associated with specific haplotypes, while in some the observed beta zero-thalassemia was of the mild type due to a considerable production of Hb F.

DNA↗
PubMed1986

Hb J-Antakya or alpha 2 beta (2)65(E9)Lys----Met in a Turkish family and Hb complutense or alpha 2 beta (2)127(H5)Gln----Glu in a Spanish family; correction of a previously published identification.

Almost 10 years ago we reported in this journal the characterization of Hb Hacettepe or alpha 2 beta (2)127(H5)Gln----Glu. Unfortunately, we have to conclude that the original characterization of this Turkish variant was in error. The corrected data are presented in this short communication. The variant (alpha 2 beta (2)65(E9)Lys----Met) was (re)named Hb J-Antakya, after the city where the family resides. An abnormal Hb, observed in a Spanish family and named Hb Complutense, had the beta 127 Gln----Glu substitution, erroneously assigned to the Turkish variant.

Amino Acid Sequence↗
PubMed1986

Beta zero-thalassemia in association with a gamma-globin gene quadruplication.

We have studied the hematology, hemoglobin composition, and globin gene arrangements in one young Turkish boy with a beta zero-thalassemia homozygosity and in 11 of his relatives. Evidence is presented that the chromosome with the beta zero-thalassemia determinant carries a gamma-globin gene quadruplication, perhaps in a -G gamma-G gamma-G gamma-A gamma-gene arrangement. The eight gamma-globin genes in this patient produced G gamma and A gamma chains in a 95 to 5 ratio, and nearly 99% of the patient's hemoglobin was of the fetal type. The clinical condition resembled that of a thalassemia intermedia. HbF levels in eight beta-thalassemia heterozygotes varied between 0.5 and 4.2% and the percentages of G gamma in this HbF averaged at 87% or 95%; this level is to some extent related to the haplotype of the normal chromosome. All subjects carried four alpha-globin genes; a new BglII polymorphism was observed within the psi alpha-globin gene.

Consanguinity↗
PubMed1985

Acute leukemia in two patients with hemophilia.

A 10-year-old classic hemophiliac and 1.5-year-old child with hemophilia B who developed acute lymphocytic and acute myelomonocytic leukemia respectively are presented. No changes in coagulation status of the patients were observed. It is suggested that hemophiliacs should be regarded as "population at risk" for the development of leukemia.

Blood Coagulation Tests↗
PubMed1985

Clinical and haematological evaluation of beta thalassaemia intermedia with increased Hb F and Hb A2 in heterozygotes: beta thalassaemia intermedia I.

Family studies were performed in 10 patients from seven different families with homozygous beta zero thalassaemia intermedia and in three patients with homozygous beta+ or compound heterozygous beta+ and beta zero thalassaemia intermedia. In nine of the 10 families at least one of the parents was found to have raised Hb A2 and Hb F. In the heterozygotes with increased Hb A2 and Hb F, the means of Hb F and MCV were significantly higher than those observed in regular Hb A2 thalassaemia heterozygotes. However, the severity of imbalance in in vitro haemoglobin synthesis was similar in these two groups. The imbalance in the alpha/non-alpha synthetic ratio was heterogeneous in the patients, being 2.1 and 4.0. Segregation of the raised Hb F from the Hb A2 beta thalassaemia determinant was found to be possible in only one of the 36 heterozygotes. This may exclude the possibility of the presence of an additional determinant responsible for the activation of the gamma chain. The G gamma/A gamma ratio of Hb F was that of the fetal type (G gamma was between 50 and 71% of the total gamma chain). The A gamma T variant of gamma chain was not detected in cis of the beta zero thalassaemia determinant characterised by increased Hb F and Hb A2. A retrospective study of 180 patients with beta thalassaemia and their parents indicated that the combined rise in Hb A2 and Hb F was more common in the heterozygous parents (11 out of 30 parents) of the patients with beta zero thalassaemia than it was in the parents of patients with beta+ thalassaemia (three out of 140 parents). The presence of increased Hb A2 and Hb F in the heterozygote may in some cases determine the relative mildness of the disease.

Female↗
PubMed1985

Clinical and haematological evaluation of beta thalassaemia intermedia characterised by unusually low Hb F and increased Hb A2: beta thalassaemia intermedia II.

A total of 15 patients from different families with thalassaemia intermedia was studied. Haematological studies showed that the fetal haemoglobin was only slightly raised, being between 2 and 11.5% of the total haemoglobin. Haemoglobin A2 was high in all cases. The family study indicated that homozygosity or compound heterozygosity for beta thalassaemia was present in five patients, while dominant inheritance was observed in three. In seven patients family studies were not sufficient to predict the genotype. Haematological findings in the parents of the homozygous patients were as severe as those seen in common Hb A2 beta thalassaemia traits. The decrease in MCH and MCV was more severe and the Hb A2 higher in homozygous patients than in cases of common beta thalassaemia major (p less than 0.01, p less than 0.01, and p less than 0.001 respectively). The imbalance in in vitro globin synthesis was more severe in classical beta thalassaemia major than in homozygous patients in this study (p less than 0.01). However, the imbalance in alpha/non-alpha synthetic ratios showed variation among the homozygous and heterozygous patients in this study (2.1 to 4.0). Haematological severity and Hb F value showed some slight variation among affected persons of the same family in the case of patients with severe beta thalassaemia heterozygosity. The G gamma/A gamma ratio of haemoglobin F was found to be close to that of the adult level. Haematological studies suggested that clinical and haematological findings were more severe in patients with homozygous beta thalassaemia than in patients with heterozygosity for beta thalassaemia. The prevalence of thalassaemia intermedia with low Hb F and increased Hb A2 was found to account for 3% of the Turkish beta thalassaemic patients diagnosed before the age of 8 years.

Female↗
PubMed1984

Two novel arrangements of the human fetal globin genes: G gamma-G gamma and A gamma-A gamma.

We describe two novel arrangements of the human fetal globin gene region: one chromosome with two linked A gamma genes (A gamma-A gamma) and two chromosomes with two linked G gamma genes (G gamma-G gamma). The gamma genes of these three chromosomes were cloned and the unusual 5' A gamma gene and one of the unusual 3' G gamma genes were partially sequenced. Both of these unusual genes differ from the genes normally found at their respective locations by a nucleotide substitution at the site of the single coding region difference between normal G gamma and A gamma genes. In both cases, the substitution is identical to the nucleotide found at that position in the normal neighboring gene. The unusual 3' G gamma gene also differs from normal A gamma genes at two other nucleotide positions, but both differences appear to be "private" or exclusive to this particular gene. These unusual fetal globin gene arrangements could have arisen from point mutations or from gene conversions of limited extent, the boundaries of which have been determined for all three chromosomes.

Base Sequence↗
PubMed1982

The percentages of Hb F and of G gamma and A gamma chains in the Hb F synthesized by reticulocytes and BFUe-derived colonies of patients with sickle cell anemia.

The synthesis of Hb F was studied in the BFUe-derived colonies of 20 SS patients after incubation with 35S methionine for 24 hours, 13 days after the start of the experiments. Similar analyses were made for isolated reticulocytes from 28 SS patients; these cells were incubated for 2 hours and occasionally for 24 hours. The G gamma and A gamma percentages were determined in these two Hb F preparations and in the Hb F of circulating red cells using two different HPL chromatographic procedures. The data show an increased production of Hb F in the colonies mainly of patients with low blood Hb F values. A close correlation was present between the % G gamma chain in peripheral red cells and the G gamma percentages observed for the Hb F synthesized in the BFUe-derived colonies and that in reticulocytes. However, the values for the reticulocytes were significantly higher than those for the colonies. These data indicate a considerable variability among SS patients in their ability to produce Hb F in in vitro colonies which may in part be due to differences in the numbers of BFUe types in circulation. The variation in G gamma and A gamma levels in Hb F synthesized in reticulocytes and BFUe-derived colonies could be the result of slight differences in the stability of the corresponding mRNA's.

Adolescent↗
PubMed1981

In vitro synthesis of hemoglobin and hemoglobin chains in the BFUe-derived colonies form person with alpha- or beta-thalassemia.

The synthesis of alpha and non-alpha chains of human hemoglobin (Hb) was studied in reticulocytes and in BFUe-derived cell colonies from patients with alpha chain or beta chain deficiencies. The subjects included normal adults (alpha alpha/alpha alpha) with or without a beta chain variant (Hb S, Hb Leslie) or an alpha chain variant (Hb G-Georgia); alpha-thalassemia-2 heterozygotes (alpha 0 alpha/alpha alpha) with an alpha chain variant (G-Georgia or G-Philadelphia); an alpha-thalassemia-1 heterozygote (alpha 0 alpha 0/alpha alpha); alpha-thalassemia-2 homozygotes (alpha 0 alpha 0/alpha 0 alpha) with a beta chain variant (Hb S), an alpha chain variant (G-Philadelphia), a Hb S homozygosity with Hb G-Philadelphia, or a Hb G-Philadelphia homozygosity; and three black beta +-thalassemia homozygotes. Data from reticulocyte in vitro synthesis analysis showed the expected deficiencies. However, similar analyses of the Hb synthesized in cell colonies (even from the black beta-thalassemia homozygotes) gave (nearly) balanced sigma alpha/sigma non-alpha ratios. It is speculated that this balanced synthesis is due to a most effective proteolysis in the immature erythroblast which rapidly removes free alpha or beta chains. The levels of Hb F and Hb A2 were considerably increased in these proerythroblasts; a two- to threefold increase in the synthesis of Hb A2 was observed over that seen in the reticulocytes.

Adolescent↗
PubMed1981

alpha-thalassemia-2 and the variability of hematological values in children with sickle cell anemia.

Seventy children homozygous for Hb S (SS) and their 111 heterozygous (AS) parents were evaluated through their erythrocytic indices, hemoglobin composition, and occasionally through in vitro Hb chain synthesis values. Three groups of SS patients and of AS parents were identified based on differences in degree of microcytosis (MCV) and (degree of hypochromia (MCH) values. The level of Hb S in the Hb S heterozygotes showed a trimodal distribution. Five SS patients had an alpha-thalassemia homozygosity (alpha(0) alpha/alpha(0) alpha; beta(s)/beta(s) which was characterized by a distinct microcytosis and hypochromia (MCV), less than or equal to 70 fl; MCH, less than or equal to 22 pp). Nine SS patients had an alpha-thalassemia heterozygosity (alpha(0)/alpha/alpha alpha; beta(s)/beta(s)) with an MCV value of 71 to 78 fl, and an MCH value of 21.3 to 26.5 pg. Four AS parents had an alpha-thalassemia-2 homozygosity with values of MCV less than or equal to 71 fl and MCH less than or equal to 23.5. The level of Hb S was less than 31%. Thirty-nine AS parents had an alpha-thalassemia-2 heterozygosity characterized by an MCV value of 72 to 79 fl, an MCH value of 23.6 to 26.5, and a level of Hb S ranging between 31.0 and 36.8%. The Hb A2 level in SS patients was significantly correlated with the RBC counts and the MCV and MCH (r = 0.38, -0.52, and -0.47, respectively). Significant correlations in AS parents were also noted between the MCV, MCH, RBC, and Hb S percentages (r = 0.62, 0.68, and -0.49, respectively). Although the data are limited, the simultaneous occurrence of an alpha-thal-2 homozygosity seems to decrease the level of Hb F in sickle cell anemia. The presence of an alpha-thal-2 heterozygosity or homozygosity together with an SS or AS condition resulted in identifiable hematologic phenotypes.

Adolescent↗
PubMed1981

Clinical and hematological evaluation of two delta 0 beta 0-thalassemia homozygotes.

Two homozygous delta 0 beta 0-thalassemia patients, one with the G gamma A gamma type and the other with the G gamma type, and their heterozygous parents are described. Red cell indices among the heterozygotes with the G gamma A gamma type of delta 0 beta 0-thalassemia were markedly different from those in heterozygotes with the G gamma type. However, the imbalance in in vitro hemoglobin synthesis was quite similar in the two heterozygous conditions. The same was observed for the homozygous patients; the in vitro chain synthesis was severely imbalanced as seen in beta-thalassemia major. The clinical and some of the hematological findings were milder in the G gamma-delta 0 beta 0-thalassemia homozygote than in the G gamma A gamma-delta 0 beta 0-thalassemia homozygote. The death of a sibling of the G gamma-delta 0 beta 0-thalassemia homozygote with a diagnosis of thalassemia major suggests that both types of delta 0 beta 0-thalassemia could follow a severe clinical and hematological course. The discovery of the G gamma type of delta 0 beta 0-thalassemia in a Turkish child shows that two types of delta 0 beta 0-thalassemia can be found in that country. Differentiation between the two types can only be made through structural analyses of Hb F.

Child↗
PubMed1981

Quantitation of three types of gamma chain of HbF by high pressure liquid chromatography; application of this method to the HbF of patients with sickle cell anemia or the S-HPFH condition.

A modification of a high pressure liquid chromatographic (HPLC) procedure is described that enables the complete separation and quantitation of the A gamma T, A gamma I, and G gamma chains in human fetal hemoglobin. The method, which is fast and accurate, requires 5 to 2000 micrograms Hb F. The purity of the Hb F is not essential and admixture of up to 70% adult Hb does not interfere with the determination. The method has been applied to the Hb F of 64 Black SS patients and 7 persons with the Hb S-HPFH (G gamma A gamma type) conditions. (A) Both "adult" G gamma to A gamma (2:3) and "newborn" G gamma to A gamma (3:2) ratios were observed in adult SS patients, 8 yr and older. Only 12% of the SS patients had the "newborn" ratio. This high G gamma to A gamma ratio may be due to a modification of the genetic switch mechanism that regulates the change of this ratio after birth. (B) Intermediate G gamma to A gamma ratios were only found in young SS patients, 5 yr of age or less. The results suggest a delayed switch of the newborn leads to adult ratio in sickle cell anemia. (C) The A gamma T chain was present in only 6% of all SS patients. One patient is homozygous for this variant chain. (D) Three of the 7 subjects with Hb S-HPFH were positive for the A gamma T chain. Its percentage was low, which suggests that the A gamma T chain gene is in trans of the HPFH determinant. (E) Quantitation of the three gamma chain types is also possible in the Hb F from Hb S heterozygotes with (nearly) normal Hb F levels. Such an analysis is useful for an evaluation of genetic conditions involving variations in the production of (different types of) Hb F.

Adolescent↗