Studies of erythrocyte protoporphyrin in anemic mutant mice: use of a modified hematofluorometer for the detection of heterozygotes for hemolytic disease.
The glucose 6-phosphate dehydrogenase (G6PD) genotype was determined in 100 male patients with homozygous sickle cell anemia (SS) by a combination of quantitative assay, cytochemical testing, and starch-gel electrophoresis.
It is speculated that a subclass (the G gamma-(G gamma A gamma)-beta+ HPFH) in which beta S chains are produced in cis to HPFH in conjunction with true beta S genes in trans may be responsible for "mild" cases of sickle cell anemia.
The allele-specific PCR approach has been modified by introducing a second mismatch at the 3'-penultimate link of the primer and used to identify the sickle cell anemia mutation (A-->T transversion in the sixth codon of the human beta-globin gene causing Glu-->Val substitution in the protein), thus obviating the problem of an interpretationally ambiguous 3'-terminal mismatch including T residue.
The model used in this study is the amplification of a 725 base-pair (bp) beta-globin gene sequence encompassing the sickle-cell anemia point mutation, followed by Cvn I digestion.
The detection of the single base pair mutations at codon 6 of the beta-globin gene is important for the prenatal diagnosis of sickle-cell anaemia and SC disease.
The clinical diversity of sickle cell anemia is strongly related to the degree of intracellular hemoglobin S (Hb S) polymerization, which in turn is dependent on the intracellular concentration of Hb S. We have recently defined a region of DNA approximately 500 bp 5' to the human beta-globin gene that acts as a silencer for the transcription of this gene and have shown that a polymorphism in this sequence is associated with a thalassemic phenotype of the beta-globin gene.
However, more patients with this type of gene arrangement must be studied before a definite conclusion can be reached regarding the influence of excess alpha-globin chains on the presentation of sickle cell anaemia.
However, more patients with this type of gene arrangement must be studied before a definite conclusion can be reached regarding the influence of excess alpha-globin chains on the presentation of sickle cell anaemia.
Compared to patients who were not G-6-PD-, there were no significant differences in the hemoglobin concentration and reticulocyte count in patients with sickle cell diseases who were G-6-PD-.
It is likely that determinants unrelated to haplotype, linked or unlinked to the beta-globin gene cluster, are the major effectors of differences in the levels of HbF in American patients with sickle cell anemia.