The molecular basis of the thalassemias has been studied in many of the wor
ld's populations. Here we report the results of the first screening for mut
ations in Vietnam. Twenty-three unrelated patients, of which 17 have Hb E/b
eta-thalassemia, were diagnosed and beta-globin mutations were detected in
all 46 chromosomes. Four previously reported South Asian mutations were fou
nd. The most common mutations were the nonsense in codon 17 (A-->T) and the
frameshift at codons 41/42 (-TTCT) (30 and 22%, respectively). The rare fr
ameshift mutation at codon 95 (+A) was present in 9% of the 46 chromosomes
studied, suggesting that it is indigenous to Vietnam. These results will se
rve as an initial database for DNA-based prenatal diagnosis of thalassemia
in Vietnam.