Hemoglobin Ozieri: a new alpha-chain variant (alpha 71(E20)Ala-->Val). Characterization using FAB- and electrospray-mass spectrometric techniques.
A new silent hemoglobin variant, Hb Ozieri (alpha 71(E20)Ala-->Val), was observed in five apparently unrelated newborn babies during a screening for hemoglobinopathies on the island of Sardinia. This asymptomatic variant was detected by means of isoelectric focusing (IEF), isolated using IEF in an immobilized ultranarrow pH-gradient and characterized at the structural level using FAB- and electrospray-mass spectrometric techniques. A Val for Ala substitution was unambiguously detected at position 71 of the alpha-globin chain. This substitution indicates that a C to T transition occurred in the GCG codon for Ala which contains one of the 35 unmethylated CpG dinucleotides of the alpha-globin gene. This observation brings the number of variants due to a mutation in the alpha-globin gene CpGs (the third instance of a silent mutation) to 13 and raises the possibility that unmethylated CpGs might be hotspots for mutations as the methylated ones.
Ferranti
P
P
Servizio di Spettrometria di Massa, CNR, Napoli, Italy.
Parlapiano
A
A
Malorni
A
A
Pucci
P
P
Marino
G
G
Cossu
G
G
Manca
L
L
Masala
B
B
D000409:Alanine; D001483:Base Sequence; D005312:Fetal Blood; D005914:Globins / Q000235:genetics; D006453:Hemoglobinopathies / Q000097:blood*; D006455:Hemoglobins, Abnormal / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D007525:Isoelectric Focusing; D007558:Italy; D013058:Mass Spectrometry / Q000379:methods; D009154:Mutation; D014633:Valine
D006455:Hemoglobins, Abnormal; C080177:hemoglobin Ozieri; D005914:Globins; D014633:Valine; D000409:Alanine