Detection of Common Beta-thalassemia Mutations by Reverse Dot Blot Analysis
Beta ()-thalassemia is the most common genetic disease of anemia caused by
mutations on beta globin gene. In Vietnam, there is a high frequency of -thalassemia carriers
with a prevalence ranging from 1.5 to 25.0 % in the different ethnic groups. The most common
mutations are the nonsense in codon (CD) 17 (A>T), codon 26 (G>A) and the frameshift at codons
41/42 (-TTCT). The polymerase chain reaction-amplification refractory mutation system (PCRARMS)
is challenged by using a great number of primer sets for detecting normal and mutated
alleles. Reverse dot-blot hybridization using oligonucleotide probes can simultaneously detect
allelic specific mutations on a membrane. In this study, we designed oligonucleotide probes
specific to the three most common mutations in CD17, CD26 and CD41/42, and used them to
optimize hybridization conditions at 68 0C in 6xSSC hybridization buffer, 2XSSC washing buffer
for detecting homozygous or hetezygous alleles of beta globin gene in fifteen individuals of 5
families. Our results were consistent with those detected by PCR-AMRS method, indicating that
oligonucleotide probes created by this study was specific, and that the reverse dot-blot hybridization
using these oligo probes was convenient for analysis of beta thalassemia disease in Vietnam