The beta-globin genes from a Thai patient compound heterozygous for beta+- and beta-0- 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-0-thalassemia mutation (41; TTC-TT) in another allele.