Prenatally diagnosed neuroblastomas are predominantly adrenal in origin and frequently cystic. The liver is the most common site of dissemination and bone involvement is notably absent. The vast majority of these infants have a favorable stage of disease (I, II, and IV-S) and favorable biologic features, and consequently have an excellent prognosis. Although surgery alone is curative for most patients, a period of observation may avoid surgery in some individuals who may achieve spontaneous regression.

Somatic mutations in the GATA1 gene are present in almost all cases of Down syndrome (DS)-associated acute megakaryoblastic leukemia (AMKL) and transient leukemia (TL). An in utero origin of the GATA1 mutation suggests it is an early leukemogenic event. To determine the detectable incidence and clinical relevance of GATA1 mutations in DS newborns, we screened Guthrie cards from 590 DS infants for mutations in the GATA1 gene. Twenty-two (3.8%) of 585 evaluable infants harbored a predicted functional GATA1 mutation; 2 were identified exclusively within intron 1. Hispanic newborns were 2.6 times more likely to have a mutated GATA1 gene than non-Hispanics (P = .02). Two newborns with a GATA1 mutation subsequently developed AMKL, and none of the infants without a functional GATA1 mutation were reported to have developed leukemia. In addition to screening for TL, a GATA1 mutation at birth might serve as a biomarker for an increased risk of DS-related AMKL.

Telomerase activity and telomere length in mononuclear cells proliferation of lymphoid or myeloid precursors with arrested (MNCs) and granulocytes from peripheral blood (PB) and bone maturation. 1 In this disorder, the leukemic clone expands in marrow (BM) specimens were studied in pediatric acute leukethe bone marrow (BM), interferes with normal hematopoiesis mia (ALL, n = 15; AML, n = 1) and pediatric solid tumor (ST) and eventually, non-hematopoietic tissues are infiltrated. patients (n = 9) at diagnosis, during and after chemotherapy. In Acute lymphocytic leukemia (ALL) was one of the first maligfour ST patients, tumor tissue was also available. For comparative analysis, MNCs from healthy donors (n = 53) were ananancies reported to respond to chemotherapy and is curable that can synthesize telomeric repeats onto chromosomes. [3][4][5][6] telomere loss in granulocytes as compared to MNCs was more Recently, borderline telomerase activity has been detected in pronounced with 1.8 vs 1 kbp, respectively (P = 0.014). Our results demonstrate that at diagnosis, telomerase was consisthuman primitive hematopoietic cells and in stimulated lymently and highly upregulated in BM and PB specimens in leukephocytes which increased significantly with cytokine-induced mia, decreased after induction therapy, and correlated with ex vivo expansion. 7-10 However, in most other normal remission. BM specimens in leukemia had higher telomerase somatic cells, telomerase has not been detected, and conseactivity, probably due to the greater leukemic burden than in quently telomere shortening may be anticipated after a limited PB. Telomeres were significantly longer in children than in number of population doublings. [11][12][13] In contrast, spon- progressive telomere length shortening in the absence of telo-