RESUMO
Mutations in Notch signaling pathway members cause developmental phenotypes that affect the liver, skeleton, heart, eye, face, kidney, and vasculature. Notch associated disorders include the autosomal dominant, multi-system, Alagille syndrome caused by mutations in both a ligand (Jagged1 (JAG1)) and receptor (NOTCH2) and autosomal recessive spondylocostal dysostosis, caused by mutations in a ligand (Delta-like-3 (DLL3)), as well as several other members of the Notch signaling pathway. Mutations in NOTCH2 have also recently been connected to Hajdu-Cheney syndrome, a dominant disorder causing focal bone destruction, osteoporosis, craniofacial morphology and renal cysts. Mutations in the NOTCH1 receptor are associated with several types of cardiac disease and mutations in NOTCH3 cause the dominant adult onset disorder CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy), a vascular disorder with onset in the 4th or 5th decades. Studies of these human disorders and their inheritance patterns and types of mutations reveal insights into the mechanisms of Notch signaling.
Assuntos
Receptores Notch/fisiologia , Transdução de Sinais , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/metabolismo , Síndrome de Alagille/genética , Síndrome de Alagille/metabolismo , Animais , Proteínas de Ligação ao Cálcio/genética , Síndrome de Hajdu-Cheney/genética , Síndrome de Hajdu-Cheney/metabolismo , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/metabolismo , Cardiopatias/genética , Cardiopatias/metabolismo , Hérnia Diafragmática/genética , Hérnia Diafragmática/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteína Jagged-1 , Proteínas de Membrana/genética , Mutação , Receptores Notch/genética , Receptores Notch/metabolismo , Proteínas Serrate-JaggedRESUMO
BACKGROUND: B-lymphoblastic leukemia/lymphomas (B-ALL/LBL) are uncommon neoplasms that may be associated with a variety of cytogenetic and molecular changes. The mechanisms by which these changes arise have not been fully described. AIMS/PURPOSE: This report describes an unusual case of B-ALL/LBL with complex clonal evolution that includes BCL2 and MYC gene rearrangements. METHODS: Immunophenotyping was performed by immunohistochemistry and flow cytometry. Traditional G-band karyotyping was accompanied by fluorescence in-situ hybridization (FISH) using break-apart and dual fusion probes. Single nucleotide polymorphisms were assessed using a high-density DNA microarray. RESULTS: The karyotype of the blasts showed reciprocal translocation of chromosomes 4 and 18, reciprocal translocation of chromosomes 8 and 14 with two copies of the oncogenic translocation derivative(14)t(8;14), and no normal chromosome 14. FISH studies showed complex IGH-BCL2 and IGH-MYC fusion signals. CONCLUSIONS: A clonal evolution model involving multiple chromosomal translocations and mitotic recombination is postulated to account for the karyotype, FISH, and microarray results but leaves unresolved the exact order of the evolutionary changes.