AIM: Observation of identical genetic changes in @entity1778 cells from monozygotic twin pairs has provided evidence for the in utero single clonal origin hypothesis of @entity1778 , with intraplacental @entity3 the basis for concordance. Investigation of this rare mixed @entity1778 ( @entity11626 ) cytogenetic abnormality aims to provide further evidence of the genetic changes that underpin this aggressive form of @entity1778 in @entity1 . METHOD: The clinical features of a monozygotic @entity1 twin pair with @entity981 ( @entity981 ) are reported. Banded chromosomal analysis and fluorescent in situ hybridization were used for cytogenetic characterization of the leukemic cells. Immunophenotype was determined by flow cytometry and polymerase chain reaction was used to determine the presence of @entity7801 -D835/I836 and @entity7801 -internal tandem duplication (ITD) mutations. RESULTS: The twins were seven weeks of age at diagnosis. Both had cytogenetic evidence for the t(1;11)(p32;q23) translocation. @entity6629 was present in a subpopulation of cells in one twin. Immunophenotypic profile at diagnosis was consistent with B precursor @entity981 ( @entity1075 , @entity11707 , @entity1116 positive, weak @entity10793 positivity, @entity2282 negative) and both were negative for @entity7801 -D835/I836 and @entity7801 -ITD mutations. CONCLUSIONS: This is the first report of monochorionic monozygotic twins harboring the t(1;11)(p32;q23) translocation. Identification of this rare translocation in both twins, indicates a common stem line and provides further evidence for the intrauterine monoclonal origin for @entity1 @entity981 with concordance explained by the shared circulation. Genetic diversity was observed in a subpopulation of cells from one twin at diagnosis. We must now utilize the sophisticated molecular biology tools available to capture changes at the genome-wide level to gain further insight into the complex events contributing to @entity11626 leukemogenesis in @entity1 .

Pre-natal, clonal origin of t(1;11)(p32;q23) XXXX in monozygotic twins.

@entity1 :: ('9606', 'Species') :: ['infants', 'infant'] @entity10793 :: ('290', 'Gene') :: ['CD13'] @entity981 :: ('MESH:D054198', 'Disease') :: ['ALL', 'acute lymphoblastic leukemia'] @entity1075 :: ('930', 'Gene') :: ['CD19'] @entity11626 :: ('4297', 'Gene') :: ['MLL'] @entity11707 :: ('100133941', 'Gene') :: ['CD24'] @entity7801 :: ('2322', 'Gene') :: ['FLT3'] @entity2282 :: ('4311', 'Gene') :: ['CD10'] @entity1778 :: ('MESH:D007938', 'Disease') :: ['lineage leukemia', 'leukemia'] @entity1116 :: ('945', 'Gene') :: ['CD33'] @entity3 :: ('MESH:D009362', 'Disease') :: ['metastasis'] @entity6629 :: ('MESH:C535318', 'Disease') :: ['Trisomy X']
@entity981 :: (MESH:D054198,Disease) :: ['acute lymphoblastic leukemia']
