OBJECTIVETo determine the molecular defects of beta-thalassemia intermedia in Guangdong Province and to provide basis for gene diagnosis and gene therapy of this disorder.

METHODSDNA analysis of the alpha, beta and gamma globin genes was performed in 18 children with beta-thalassemia intermedia from Guangdong Province using polymerase chain reaction (PCR), microarray technique, Southern blot and direct sequencing.

RESULTSOf the 18 patients,one was identified as the homozygote of TATA box-28 (A-->G) change, one as the homozygote of betaE26 (G-->A) mutation, ten as compound heterozygotes of TATA box- 28 (A-->G) mutation with other beta-globin mutations, two as compound heterozygotes of betaE26 (G-->A ) mutation with other beta globin mutations, and four as double heterozygotes for beta globin and alpha globin mutations including -SEA and -alpha(4.2).

CONCLUSIONSThe molecular defects of beta- thalassemia intermedia in Guangdong Province were highly heterogeneous and its spectrum was different from the reports from other provinces of China.