The beta-globin gene from a patient with homozygous beta-thalassemia in Taiwan was cloned and extensively sequenced. Four nucleotides in the codon for amino acids, 41 and 42, are deleted. This change generates a frame-shift mutation and a termination codon in the new 59th codon. Some changes in nucleotide sequence were also found in intervening sequences IVS1 and IVS2, and Exon3, and were considered to be sequence polymorphisms.