The nature of alpha-thalassemia in this patient was investigated both by liquid hybridization and by the Southern method of gene mapping, in which DNA is digested with restriction endonucleases and the DNA fragments that contained the alpha-globin structural gene identified by hybridization with complementary DNA.
The nature of alpha-thalassemia in this patient was investigated both by liquid hybridization and by the Southern method of gene mapping, in which DNA is digested with restriction endonucleases and the DNA fragments that contained the alpha-globin structural gene identified by hybridization with complementary DNA.
Hybridization patterns of DNA restriction enzyme fragments showed that in HbQ-alpha 2 74 Asp replaced by His beta 2-alpha-thalassemia one chromosome has both alpha-globin genes deleted and the other chromosome, which carries the alpha-mutant gene, has one alpha-globin gene deleted.
Hybridization patterns of DNA restriction enzyme fragments showed that in HbQ-alpha 2 74 Asp replaced by His beta 2-alpha-thalassemia one chromosome has both alpha-globin genes deleted and the other chromosome, which carries the alpha-mutant gene, has one alpha-globin gene deleted.
Examination of red cell indices showed a highly significant reduction in the average MCV and MCH of parents with positive HbH preparations, and a diagnosis of alpha-thalassaemia (based on the presence of HbH inclusion bodies and reductions in MCV and/or MCH) was made in at least one parent in the majority of couples with both partners tested, suggesting that alpha-thalassaemia trait in people of Mediterranean origin is generally associated with detectable haematological changes.
Three Hb Leslie heterozygotes with presumably four, three (heterozygous alpha-thalassemia-2), and two (homozygous alpha-thalassemia-2) active alpha-chain genes and with 33%, 22% and 11% Hb Leslie respectively, and one patient with the Hb Leslie beta(0)-thalassemia condition with more than 85% Hb Leslie were studied.
The lowest SI values were encountered in patients with associated alpha-thalassaemia who also had the lowest WBC count and MCV and the highest RBC count and packed cell volume.
The test appears to identify patients, such as those with the Thai and Filipino deletion variants, whose alpha-thalassemiacannot be definitively characterized by DNA testing when only alpha- and zeta-globin probes are used in the analysis.
This genetic study supports the critical role of the LCR in the transcriptional activation of the human alpha-globin gene cluster and substantiates the importance of LCR deletions in the etiology of alpha-thalassemia.
This genetic study supports the critical role of the LCR in the transcriptional activation of the human alpha-globin gene cluster and substantiates the importance of LCR deletions in the etiology of alpha-thalassemia.
The frequency of deletional alpha-thalassaemia in a Javanese population sample (n = 103) was investigated at three restriction sites of the alpha-globin gene (BamHI, BglII and RsaI).
The frequency of deletional alpha-thalassaemia in a Javanese population sample (n = 103) was investigated at three restriction sites of the alpha-globin gene (BamHI, BglII and RsaI).
A rapid and inexpensive polymerase chain reaction (PCR) based strategy is described which detects the three common, severe alpha thalassaemia determinants observed in southeast Asia (--SEA) and the Mediterranean (--MED and -(alpha)20.5).
A rapid and inexpensive polymerase chain reaction (PCR) based strategy is described which detects the three common, severe alpha thalassaemia determinants observed in southeast Asia (--SEA) and the Mediterranean (--MED and -(alpha)20.5).
A rapid and inexpensive polymerase chain reaction (PCR) based strategy is described which detects the three common, severe alpha thalassaemia determinants observed in southeast Asia (--SEA) and the Mediterranean (--MED and -(alpha)20.5).
A rapid and inexpensive polymerase chain reaction (PCR) based strategy is described which detects the three common, severe alpha thalassaemia determinants observed in southeast Asia (--SEA) and the Mediterranean (--MED and -(alpha)20.5).
A rapid and inexpensive polymerase chain reaction (PCR) based strategy is described which detects the three common, severe alpha thalassaemia determinants observed in southeast Asia (--SEA) and the Mediterranean (--MED and -(alpha)20.5).
A rapid and inexpensive polymerase chain reaction (PCR) based strategy is described which detects the three common, severe alpha thalassaemia determinants observed in southeast Asia (--SEA) and the Mediterranean (--MED and -(alpha)20.5).
During three months, 67.2% of all (748) newborns were screened: 122 (24.3%) had an abnormal hemoglobin pattern, of which 53 (43.4%) had a hemoglobinopathy (HbS or HbC), 64 (52.2%) had alpha-thalassemia (HbBarts greater than 0.5%, corresponding to heterozygous or homozygous alpha-thalassemia-2), and 5 (4.1%) had a hemoglobinopathy plus alpha-thalassemia.
Besides the common types of deletional alpha-thalassaemia-2 (-3.7 kb and -4.2 kb) we observed a nondeletional alpha-thalassaemia-2 that results from an A----G mutation (AATAAA----AATGAA) in the polyadenylation signal of the alpha 2-globin gene: the same A----G replacement is present in the psi alpha l gene.
Besides the common types of deletional alpha-thalassaemia-2 (-3.7 kb and -4.2 kb) we observed a nondeletional alpha-thalassaemia-2 that results from an A----G mutation (AATAAA----AATGAA) in the polyadenylation signal of the alpha 2-globin gene: the same A----G replacement is present in the psi alpha l gene.
We have identified an individual with alpha-thalassemia in whom structurally normal alpha-globin genes have been inactivated in cis by a discrete de novo 35-kilobase deletion located approximately 30 kilobases 5' from the alpha-globin gene cluster.
We have identified an individual with alpha-thalassemia in whom structurally normal alpha-globin genes have been inactivated in cis by a discrete de novo 35-kilobase deletion located approximately 30 kilobases 5' from the alpha-globin gene cluster.