Hb Antalya [codons 3-5 (Leu-Thr-Pro-->Ser-Asp-Ser)]: a new unstable variant leading to chronic microcytic anemia and high Hb A2.
A novel beta-thalassemia mutation, not previously reported in the literature, was identified by direct DNA sequencing of the beta-globin gene. Hematological investigation of a 26-year-old woman due to her increased Hb A2 level (6.2%) led to the identification of a heterozygosity for a 9 bp (TCTGACTCT) deletion/insertion at codons 3-5. This was found to be the result of a deletion of cytosine (-C) at codon 5 (one of the nucleotides in the 13th or 14th position of exon 1). and an insertion of thymine (+T) in front of codon 3 at the 10th nucleotide in exon 1 of the beta-globin gene. As a result of these mutations, the amino acids at codons 3-5 were changed from Leu-Thr-Pro to Ser-Asp-Ser. The whole frameshift was prevented by this rearrangement in the beta-globin gene. In addition, this result may provide important clues to identify critical amino acids responsible for stabilization of the hemoglobin tetramer.
Keser
I
I
Department of Medical Genetics, School of Medicine, Akdeniz University, Dumlupinar Bulvari, Antalya, Turkey. keser@hipokrat.med.akdeniz.edu.tr
Kayisli
O G
OG
Yesilipek
A
A
Ozes
O N
ON
Luleci
G
G
D000328:Adult; D019943:Amino Acid Substitution; D000740:Anemia / Q000209:etiology / Q000235:genetics / Q000473:pathology; D001483:Base Sequence; D002908:Chronic Disease; D004913:Erythrocytes, Abnormal / Q000473:pathology; D005260:Female; D014644:Genetic Variation; D006443:Hemoglobin A2 / Q000032:analysis; D006455:Hemoglobins, Abnormal / Q000009:adverse effects / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D009154:Mutation; D017384:Sequence Deletion; D017086:beta-Thalassemia / Q000235:genetics
D006455:Hemoglobins, Abnormal; C473009:hemoglobin Antalya; D006443:Hemoglobin A2