Tetrasomy 21 transient leukemia with a GATA1 mutation in a phenotypically normal trisomy 21 mosaic infant: case report and review of the literature

Infants with constitutional trisomy 21 are at increased risk of developing transient and acute megakaryoblastic leukemia (AMKL). Mutations in GATA1 have been identified in trisomy 21 patients with AMKL, and this lesion is thought to be an initial event by virtue of its presence during transient leukemia. Transient leukemia is also observed in phenotypically normal infants albeit much less commonly so. Almost all these infants are mosaic for trisomy 21, and the clinical course of transient leukemia recapitulates that observed in constitutional trisomy 21. We report a phenotypically normal infant with tetrasomy 21 transient leukemia, GATA1 mutation within exon 2, and trisomy 21 mosaicism restricted to the hematopoietic tissue. Two years after diagnosis, low levels of trisomy 21 persisted in the peripheral blood, which resolved 2.5 years after diagnosis. The GATA1 mutation was not detected at last follow-up. The literature review identified 32 phenotypically normal infants with transient leukemia. Ninety-one percent (29 of 32) were observed and three received chemotherapy at diagnosis of transient leukemia. Nineteen percent (6 of 32) developed acute leukemia, and four continued in remission (two died). Transient leukemia in trisomy 21 mosaicism recapitulates the condition observed in constitutional trisomy 21 at the biological and clinical levels. Infants should be followed for the development of acute leukemia.     

A rare case of GATA1 negative chemoresistant acute megakaryocytic leukemia in an 8‐month‐old infant with trisomy 21

Children with Down syndrome (DS) have a unique form of acute megakaryocytic leukemia (AMKL) characterized by the presence of mutations in the GATA1 gene leading to increased chemosensitivity and a favorable outcome. We describe an 8‐month‐old male with DS who was diagnosed with AMKL without a mutation in the GATA1 gene. The patient was treated according to the DS‐AML‐regimen but his disease progressed and he succumbed 9 months later. This rare case of DS AMKL without a GATA1 mutation with an unfavorable outcome suggests that GATA1 testing may play a useful role in initial stratification. Pediatr Blood Cancer 2010;54:1048–1049 © 2010 Wiley‐Liss, Inc.     

Immunoreactive copper-zinc superoxide-dismutase (SOD-1) in mosaic trisomy 21 and normal subjects

Copper-zinc superoxide-dismutase (SOD-1) (E.C. 1.15.11) levels were measured in 9 children with mosaic trisomy 21 as identified by R, H, G-banding technics. Radioimmunoassay of erythrocytes and fibroblasts did not demonstrate any significant correlation between levels of SOD-1 and percentage of trisomic 21 cells in the two target cell populations studied.     

Comparison of mental development in individuals with mosaic and trisomy 21 Down's syndrome.

During the past 15 years about 350 children with Down's syndrome have been seen at Children's Hospital of Los Angeles for psychological evaluation along with medical visits and other laboratory tests. Among this group there were 25 mosaic Down's syndrome children identified by chromosome analyses. They were matched for sex and chronological age with 25 trisomy 21 subjects and compared on psychological tests. The mosaic group demonstrated significantly higher intellectual potential, better verbal facility, and less visual perceptual difficulties than the trisomy 21 group. Their behavioral adjustment and personality characterisitcs were similar to those observed in other types of Down's syndrome. Since present psychological assessment techniques do not permit reaching valid conclusions about the ultimate intellectual status in very young infants with Down's syndrome, physicians and other professionals need to be careful when recommending early placement outside the home based merely upon the diagnosis.     

Spontaneous remission in congenital leukemia is not related to (mosaic) trisomy 21: case presentation and literature review

Congenital leukemia is seldomly diagnosed. Cases should be differentiated from transient leukemoid reaction, which is noted in Down syndrome. Outcome in congenital leukemia is poor, but spontaneous remissions have been described. The authors report on a female neonate with myeloid leukemia of the skin; no blood and bone marrow involvement was noted. Constitutional 47,XX,+21 was excluded. In situ hybridization on a paraffin-embedded skin biopsy sample did not show trisomy 21 in the leukemia lesions. No antileukemia therapy was given. During follow-up, small nodules (diameter up to 3 mm) on the soles of both feet came and went over a 3-month period. The child is now 3.5 years old and well. To date, 18 cases of congenital leukemia showing spontaneous remission have been described in the literature, almost exclusively myeloid leukemia (FAB M4 and M5). Congenital leukemia confined to the skin was described in only 4 cases. On follow-up, 6 cases relapsed; only one of them initially had skin involvement only. The data from this patient and literature indicate that cytostatic treatment should start only if the malignancy interferes with vital parameters. In case of relapse or progression, initial postponement of chemotherapy in these frail neonates will result in less toxicity and probably a better survival.     

Isolated trisomy 21 in blasts of an acute lymphoblastic leukemia

A two years and four months old boy without evidence of Down's syndrome exhibited a trisomy 21 in his acute lymphoblastic leucemic cells. During remission this chromosomal change disappeared. The cytogenetic examination of malignant cells serves an important tool in diagnosis and follow-up of acute leucemia as well as bone marrow transplantation.     

Transient myeloproliferative disorder associated with trisomy 21, a wide range syndrome: Report of two cases with trisomy 21 mosaicism

Transient myeloproliferative disorder (TMD) is an uncommon syndrome strongly associated with abnormalities of chromosome 21. Blast transient proliferation appears most frequently at neonatal age and usually resolves spontaneously in two or three months. Two patients, a girl and a boy, with neonatal onset of TMD are reported. They both presented trisomy 21 mosaicism according to bone marrow cytogenetic analysis. Patient 1, on one end of the spectrum, showed a “classic” benign course with rapid resolution and favorable outcome. Patient 2, on the other hand, had two blast outbursts both followed by spontaneous remissions. He failed to thrive and never reached a good general condition, dying at 5 months of age from a respiratory infectious complication. The necropsy showed generalized extramedullary hemopoiesis without evidence of bone marrow blast infiltration or myelofibrosis. TMD has some clinical and laboratory features that make it unique and distinguishable from true congenital leukemia with which it may be initially mistaken. It usually has a benign course followed by a favorable outcome. As trisomy 21 mosaicism may not have overt phenotypic stigmata, it is possible that many cases of TMD in these children may have a silent, non-detected course. We also conclude that a favorable outcome is not always to be expected in TMD. © 1995 Wiley-Liss, Inc.     

Acute megakaryoblastic leukemia. Relation to trisomy 21]

Two cases of acute megakaryoblastic leukemia in a 4 month-old and a 13 year-old girl are described. In the first case who presented with a large hepatomegaly and portal fibrosis, the diagnosis was made from the surface phenotyping of megakaryoblasts; a trisomy 13, 14 and 19 and an extra chromosome X were present in the bone marrow. An electron microscopy study of megakaryoblasts was necessary to identify the second case. Both children died shortly after treatment (cytosine-arabinoside at low dosage in the first case and polychemotherapy in the second). The 51 other cases reported in the literature are reviewed.