Distribution of common genetic subgroups in childhood acute lymphoblastic leukemia in four developing countries

Abstract

An international project was conducted to identify the common acute lymphoblastic leukemia (ALL)-specific fusion genes ( ETV6-RUNX1, MLL-AF4, TCF3-PBX1, and BCR-ABL1) in developing countries to provide additional prognostic information at diagnosis. A total of 181 children with newly diagnosed ALL were tested by reverse transcriptase–polymerase chain reaction at laboratories in India, Pakistan, Myanmar, and Sudan, following a common protocol. To our knowledge, this report is novel in its report from these countries, except India. Across the four countries, the ETV6-RUNX1 ( TEL-AML1) fusion gene was present in only 5% of cases. All the positive samples were from children aged 1 to 10 years, in whom the prevalence of this fusion gene, which is associated with good prognosis, was 7.4% (9 out of 121 samples), a much lower rate than reported from Western populations. In the 18 ALL cases tested in Sudan, a notable excess of MLL-AF4 (17%) and BCR-ABL1 (22%) fusion genes was found. This study highlights the need for wider international surveys of the molecular epidemiology of ALL.