Extent and high frequency of a short conversion between the human A gamma and G gamma fetal globin genes.
Southern blotting and DNA sequencing after polymerase chain reaction (PCR) amplification provide evidence for the frequent occurrence (in 7 out of 24 chromosomes) of a short conversion G gamma----A gamma in the 3' end of the human fetal A gamma globin gene. This short conversion is characterized by the presence, 3 nucleotides downstream from the termination codon of the A gamma gene, of the TCAC sequence that is normally present at the equivalent position at the 3' end of the G gamma gene; it is therefore identical to a conversion already described. Interestingly, we have found that this conversion is associated with the presence of the HindIII polymorphic restriction site in the A gamma IVS2, occupying an equivalent position in both the G gamma and A gamma genes. Our observations strengthen the hypothesis that the presence of the HindIII polymorphic restriction site in A gamma IVS2 and the presence of the sequence TCAC at the 3' end of the A gamma gene might be the result of a single conversion event.
Centre de Génétique Moléculaire et Cellulaire, C.N.R.S. UMR 106, Université de Lyon, Villeurbanne, France.
J
J
Starck
R
R
Bouhass
F
F
Morlé
J
J
Godet
D001483:Base Sequence; D005312:Fetal Blood; D005319:Fetal Hemoglobin / Q000235:genetics*; D005785:Gene Conversion; D005914:Globins / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping
D005914:Globins; D005319:Fetal Hemoglobin