Identification of two new alpha-thalassemia mutations in exon 2 of the alpha1-globin gene.
The most common causes of alpha-thalassemia are deletions that remove one or both of the functional alpha-globin genes. In addition, more than 30 different point mutations and small deletions/insertions have been reported for the alpha-globin genes. Here, we describe two new mutations occurring in exon 2 of the alpha1-globin gene. One mutation is an insertion of 21 bp that gives rise to a predicted alpha-globin chain containing a duplication of amino acid residues 93-99. The second mutation is a 33 bp deletion resulting in a predicted alpha-globin chain that is missing amino acid residues 64-74. Neither mutation results in a detectable hemoglobin variant, indicating that the variant alpha-globin chains are highly unstable. Carriers of these mutations have mild microcytosis and the phenotype of alpha+-thalassemia trait.
Waye
J S
JS
Provincial Hemoglobinopathy and DNA Diagnostic Laboratory, Hamilton Regional Laboratory Medicine Program, Ontario, Canada. wayej@mcmail.mcmaster.ca
Eng
B
B
Patterson
M
M
Carcao
M D
MD
Chang
L
L
Olivieri
N F
NF
Chui
D H
DH
D001483:Base Sequence; D002648:Child; D004913:Erythrocytes, Abnormal; D005091:Exons; D005192:Family Health; D005260:Female; D018740:Genetic Heterogeneity; D005914:Globins / Q000235:genetics*; D006801:Humans; D008297:Male; D010641:Phenotype; D011247:Pregnancy; D011296:Prenatal Diagnosis; D017384:Sequence Deletion; D017085:alpha-Thalassemia / Q000235:genetics*
D005914:Globins