TEL-AML1 gene fusion due to chromosomal translocation is frequently seen in the common form of childhood acute lymphoblastic leukaemia.     ///    We amplified and sequenced the genomic TEL-AML1 fusion gene with a long-distance inverse PCR method.     ///    "We identified, by reverse-transcriptase PCR screening of blood or bone marrow, TEL-AML1 fusion in 12 children, plus a pair of identical twins, aged 2-5 years from Italy and the UK, who had newly diagnosed acute lymphoblastic leukaemia. "    ///    "Primers were designed that could be used in short-range PCR to screen for patient-specific, leukaemia clone-specific TEL-AML1 genomic fusion sequences in neonatal blood spots from each child. "    ///    "We initially identified TEL-AML1 fusion sequences in blood spots from the identical twins, diagnosed with concordant acute lymphoblastic leukaemia at age 4 years, who shared a single or clonotypic TEL-AML1 sequence that suggested prenatal origin in one twin. "