A gene conversion located 5' to the A gamma gene in linkage disequilibrium with the Bantu haplotype in sickle cell anemia.
Cloning and sequencing of the gamma-globin gene of a sickle cell anemia patient homozygous for the Bantu haplotype has revealed a gene conversion that involves the replacement of an A gamma sequence by a G gamma sequence in the promoter area of the A gamma gene. This event is similar to another gene conversion believed to be responsible for the very high homology between gamma-globin genes, suggesting that the promoter area of these genes is prone to this type of genetic rearrangement. Further analysis demonstrated that the chromosome bearing this gene conversion has a very high frequency among Bantu chromosomes and a very low or nil frequency in other haplotypes linked to the beta s gene. No correlation was found between the G gamma/A gamma ratio and the presence of the gene conversion among Bantu haplotype patients, thus excluding a portion of the gamma gene sequence in the determination of this ratio.
Bouhassira
E E
EE
Division of Hematology, Albert Einstein College of Medicine, Bronx, NY 10461.
Lachman
H
H
Krishnamoorthy
R
R
Labie
D
D
Nagel
R L
RL
D000755:Anemia, Sickle Cell / Q000235:genetics*; D001483:Base Sequence; D005784:Gene Amplification; D005785:Gene Conversion; D008040:Genetic Linkage; D005914:Globins / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes
D015345:Oligonucleotide Probes; D005914:Globins