Identification of five rare mutations including a novel frameshift mutation causing β⁰-thalassemia in Thai patients with β⁰-thalassemia/hemoglobin E disease

Abstract

6 out of 14 uncharacterized β-thalassemia alleles from 187 Thai β-thalassemia/HbE patients were identified by direct sequencing of DNA amplified by polymerase chain reaction. A novel mutation occuring from an insertion of adenosine in codon 95, which results in a shift of the reading frame with the terminator at the new codon 101, was detected in one patient. In addition, two frameshift mutations not previously reported among the Thai population were also detected in 3 patients: one with a deletion of thymidine in codon 15 and two with an insertion of cytidine in codons 27/28. A frameshift mutation that occurred from a cytidine deletion in codon 41 was also found in one patient in this study. The remaining case was as amber mutation, GAG-TAG, in codon 43 in exon 2 of the β-globin gene. These mutations bring the number of mutations known to be present in the Thai population to a total of 20, 15 of which were detected in β-thalassemia/HbE patients. © 1992.