The beta-globin genes from a Thai patient compound heterozygous for beta(+)- and beta zero-thalassemias were investigated. Amplification and DNA analysis of genomic DNA by the polymerase chain reaction procedure permitted the identification of the beta-Malay mutation (beta 19;AAC-AGC) in one allele and a novel beta zero-thalassemia mutation (41;TTC-TT) in another allele.