scholarly journals High fetal hemoglobin production in sickle cell anemia in the eastern province of Saudi Arabia is genetically determined

Blood ◽  
1986 ◽  
Vol 67 (5) ◽  
pp. 1404-1410 ◽  
Author(s):  
BA Miller ◽  
M Salameh ◽  
M Ahmed ◽  
J Wainscoat ◽  
G Antognetti ◽  
...  

Abstract Homozygous sickle cell disease in the eastern province of Saudi Arabia is clinically mild. Circulating fetal hemoglobin levels of 16.0 +/- 7.4% were found in these anemic patients, but only 1.09 +/- 0.97% in their sickle trait parents. To determine whether these sickle cell anemia patients inherit an increased capacity to synthesize fetal hemoglobin, a radioimmunoassay of fetal and adult hemoglobin was performed on erythroid progenitor (BFU-E)-derived erythroblasts from Saudi Arabian sickle cell patients and their parents. Mean fetal hemoglobin content per BFU-E-derived erythroblast from Saudi Arabian sickle cell patients was 6.2 +/- 2.4 pg/cell or 30.4 +/- 8.6% fetal hemoglobin (normal 1.1 +/- 0.7 pg/cell and 5.1 +/- 1.8%). Linear regression analysis of % HbF in peripheral blood versus % HbF per BFU-E- derived cell showed a positive correlation with an r of 0.65. The variance of the intrinsic capacity to produce HbF may account for almost 40% (r2) of the variance of circulating fetal hemoglobin but other factors, particularly selective survival of F cells, must also contribute significantly. Despite virtually normal HbF levels in sickle trait parents of these Saudi patients, mean fetal hemoglobin production per BFU-E-derived erythroblast in these individuals was elevated to 3.42 +/- 1.79 pg/cell or 16.1 +/- 6.4% fetal hemoglobin, and the magnitude of fetal hemoglobin production found in parents correlated with that of the patients. These data indicate that the high fetal hemoglobin in Saudi sickle cell disease is genetically determined but expressed only during accelerated erythropoiesis. Further evidence of such genetic determination was provided by analysis of DNA polymorphisms within the beta-globin gene cluster on chromosome 11. This revealed a distinctive 5′ globin haplotype (+ + - + +) on at least one chromosome 11 in all high F SS and AS tested. The precise relationship of this haplotype to HbF production in this population remains to be defined.

Blood ◽  
1986 ◽  
Vol 67 (5) ◽  
pp. 1404-1410
Author(s):  
BA Miller ◽  
M Salameh ◽  
M Ahmed ◽  
J Wainscoat ◽  
G Antognetti ◽  
...  

Homozygous sickle cell disease in the eastern province of Saudi Arabia is clinically mild. Circulating fetal hemoglobin levels of 16.0 +/- 7.4% were found in these anemic patients, but only 1.09 +/- 0.97% in their sickle trait parents. To determine whether these sickle cell anemia patients inherit an increased capacity to synthesize fetal hemoglobin, a radioimmunoassay of fetal and adult hemoglobin was performed on erythroid progenitor (BFU-E)-derived erythroblasts from Saudi Arabian sickle cell patients and their parents. Mean fetal hemoglobin content per BFU-E-derived erythroblast from Saudi Arabian sickle cell patients was 6.2 +/- 2.4 pg/cell or 30.4 +/- 8.6% fetal hemoglobin (normal 1.1 +/- 0.7 pg/cell and 5.1 +/- 1.8%). Linear regression analysis of % HbF in peripheral blood versus % HbF per BFU-E- derived cell showed a positive correlation with an r of 0.65. The variance of the intrinsic capacity to produce HbF may account for almost 40% (r2) of the variance of circulating fetal hemoglobin but other factors, particularly selective survival of F cells, must also contribute significantly. Despite virtually normal HbF levels in sickle trait parents of these Saudi patients, mean fetal hemoglobin production per BFU-E-derived erythroblast in these individuals was elevated to 3.42 +/- 1.79 pg/cell or 16.1 +/- 6.4% fetal hemoglobin, and the magnitude of fetal hemoglobin production found in parents correlated with that of the patients. These data indicate that the high fetal hemoglobin in Saudi sickle cell disease is genetically determined but expressed only during accelerated erythropoiesis. Further evidence of such genetic determination was provided by analysis of DNA polymorphisms within the beta-globin gene cluster on chromosome 11. This revealed a distinctive 5′ globin haplotype (+ + - + +) on at least one chromosome 11 in all high F SS and AS tested. The precise relationship of this haplotype to HbF production in this population remains to be defined.


Blood ◽  
1987 ◽  
Vol 70 (3) ◽  
pp. 716-720 ◽  
Author(s):  
BA Miller ◽  
M Salameh ◽  
M Ahmed ◽  
N Olivieri ◽  
G Antognetti ◽  
...  

Erythrocytes and progenitor-derived erythroblasts of sickle cell anemia patients from the Eastern Province of Saudi Arabia contain increased fetal hemoglobin and G gamma globin. A distinctive DNA polymorphism haplotype in the beta globin gene cluster (++- +-), tightly coupled to a C----T substitution at position -158 5′ to the cap site of the G gamma globin gene, is strongly associated with sickle cell disease in this region. To determine whether the increased fetal hemoglobin production and/or elevated G gamma globin content are tightly linked to this haplotype, we studied 55 members of five Saudi families in which sickle cell disease is present. The results did not suggest a tight linkage of the haplotype to increased fetal hemoglobin production. On the other hand, several sickle trait family members heterozygous for the haplotype had normal fetal hemoglobin production in culture but elevated G gamma to A gamma ratios in peripheral blood. This observation suggests that in this genetic background increased expression of the G gamma globin gene may occur without a measurable increase in total fetal hemoglobin production. The family studies also clearly demonstrate that increased fetal hemoglobin production by erythroid progenitors is dependent on zygosity for the sickle gene in this population. These findings strongly suggest that other factors, such as the products of genes stimulated by hemolytic stress or other genetic determinants associated with the Saudi beta S chromosome, may interact with the -158 C----T substitution and influence gamma globin gene expression in this population.


Blood ◽  
1987 ◽  
Vol 70 (3) ◽  
pp. 716-720 ◽  
Author(s):  
BA Miller ◽  
M Salameh ◽  
M Ahmed ◽  
N Olivieri ◽  
G Antognetti ◽  
...  

Abstract Erythrocytes and progenitor-derived erythroblasts of sickle cell anemia patients from the Eastern Province of Saudi Arabia contain increased fetal hemoglobin and G gamma globin. A distinctive DNA polymorphism haplotype in the beta globin gene cluster (++- +-), tightly coupled to a C----T substitution at position -158 5′ to the cap site of the G gamma globin gene, is strongly associated with sickle cell disease in this region. To determine whether the increased fetal hemoglobin production and/or elevated G gamma globin content are tightly linked to this haplotype, we studied 55 members of five Saudi families in which sickle cell disease is present. The results did not suggest a tight linkage of the haplotype to increased fetal hemoglobin production. On the other hand, several sickle trait family members heterozygous for the haplotype had normal fetal hemoglobin production in culture but elevated G gamma to A gamma ratios in peripheral blood. This observation suggests that in this genetic background increased expression of the G gamma globin gene may occur without a measurable increase in total fetal hemoglobin production. The family studies also clearly demonstrate that increased fetal hemoglobin production by erythroid progenitors is dependent on zygosity for the sickle gene in this population. These findings strongly suggest that other factors, such as the products of genes stimulated by hemolytic stress or other genetic determinants associated with the Saudi beta S chromosome, may interact with the -158 C----T substitution and influence gamma globin gene expression in this population.


Hemoglobin ◽  
2020 ◽  
Vol 44 (2) ◽  
pp. 78-81 ◽  
Author(s):  
Amein K. Al-Ali ◽  
Ahmed Alsulaiman ◽  
Alhusain J. Alzahrani ◽  
Obeid T. Obeid ◽  
Chitti Babu Vatte ◽  
...  

2018 ◽  
Vol 140 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Zhara A. Al-Ali ◽  
Rana K. Fallatah ◽  
Esra A. Aljaffer ◽  
Eman R. Albukhari ◽  
Neriman Sadek Al-Ali ◽  
...  

Disease severity of sickle cell anemia is highly variable, and it is commonly accepted that fetal hemoglobin (HbF) levels play a major role as an ameliorating factor. Investigation of genetic variants have identified several genes to be the principal influencers of HbF regulation. Here, we further elucidated the association of rs4527238 and rs35685045 of ANTXR1 genes in the context of HbF level variance in sickle cell anemia patients of the Arab-Indian haplotype. Samples from 630 sickle cell anemia patients were analyzed for the mutations at 2 specific locations of the ANTXR1 gene by TaqMan®-based real-time PCR. The CC genotype (p = 0.018) of rs4527238 and the TT genotype (p = 0.048) of rs35685045 of ANTXR1 were found to be significantly associated with low HbF expression. The frequency of the CC genotype of rs4527238 was observed to be high in the low HbF patient group compared to the high HbF group (p = 0.009). Likewise, the frequency of the TT genotype of rs35685045 was also high among the low HbF group (p = 0.017). The ANTXR1 genetic mutations and the association with HbF expression in the Arab-Indian haplotype sickle cell patients revealed that the ANTXR1 gene may be a major HbF modulator leading to potential therapeutic options that should be further explored.


1989 ◽  
Vol 114 (6) ◽  
pp. 973-976 ◽  
Author(s):  
M.I. El Mouzan ◽  
Baker H. Al Awamy ◽  
M.T. Al Torki ◽  
G.A. Niazi

Author(s):  
Amein K. Al‐Ali ◽  
Ahmed Alsulaiman ◽  
Mohammed Alfarhan ◽  
Surinder Safaya ◽  
Chitti Babu Vatte ◽  
...  

Blood ◽  
1991 ◽  
Vol 78 (1) ◽  
pp. 212-216 ◽  
Author(s):  
EP Orringer ◽  
DS Blythe ◽  
AE Johnson ◽  
G Jr Phillips ◽  
GJ Dover ◽  
...  

A rationale for clinical trials of hydroxyurea (HU) treatment in sickle cell disease is that the agent increases red blood cell (RBC) fetal hemoglobin content. However, an additional effect of HU is to raise the mean corpuscular volume (MCV). To investigate the action of HU in a species that makes no electrophoretically distinguishable fetal hemoglobin, we treated dogs with the drug and compared their response to that of five patients with sickle cell anemia. Both dogs and patients had an increase in MCV, but the effect of HU treatment on the mean corpuscular hemoglobin concentration (MCHC), density, and water content of the RBCs differed in the two species. The dog RBCs became low in MCHC, high in ion and water content, and low in mean density. Thus, HU can raise MCV and lower MCHC without influencing fetal hemoglobin synthesis. A different pattern was seen in the sickle cell patients during HU treatment. Although the MCV of their RBCs increased, there was no change in MCHC, ion content, or mean density. A notable change in the sickle cell patients' blood was that two subpopulations of cells were nearly eliminated during HU treatment; the hypodense reticulocyte fraction and the hyperdense fraction that contains irreversibly sickled cells. These findings lead us to suggest that trials of HU in sickle cell disease must recognize the possibility that any beneficial effect of this agent might be due not only to an increase in hemoglobin F alone, but perhaps also to the associated increase in MCV or the altered RBC density profile.


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