Hemophagocytic syndrome in a patient with Fanconi anemia and VACTERL association / Síndrome hemofagocítica em paciente com anemia de Fanconi e associação VACTERL

INTRODUCTION: Hemophagocytic syndrome results from hyperactivity of histiocytes and lymphocytes, triggered by infections, mainly viral by cytomegalovirus, Epstein-Barr and herpes. Fanconi anemia (FA) is a rare genetic disease with heterogeneous symptoms common to other diseases such as VACTERL, a disease of unknown etiology in which there are several congenital malformations. The concomitance of Fanconi and VACTERL anemia occurs in 5 to 30% of FA patients. REPORT: A 14-month-old male infant was admitted to investigate fever, hepatosplenomegaly, and granulopenia. The patient was diagnosed with hemophagocytic syndrome due to hyperferritinemia, bone marrow hemophagocytosis, transaminase elevation, decreased fibrinogen, and cytomegalovirus (CMV) infection confirmed by serology and PCR. The test with mitomycin C (MMC) showed chromosomal fragility. The patient was diagnosed with a VACTERL/FA association for having a clinic and a test compatible with both FA and VACTERL. CONCLUSION: The VACTERL/FA association is seldom described, but is present in pediatric medical practice. This study presented the main clinical-laboratory aspects and reviewed the main aspects of the concurrence of this pathology.

INTRODUÇÃO: A síndrome hemofagocítica decorre da hiperatividade de histiócitos e linfócitos e é desencadeada por infeções, principalmente virais por citomegalovírus, Epstein-barr e herpes. A anemia de Fanconi (AF) é uma doença genética rara com sintomas heterogêneos em comum a outras doenças como a associação VACTERL, uma doença de etiologia desconhecida na qual existe diversas mal formações congênitas. A concomitância da anemia de Fanconi e VACTERL é descrita em 5 a 30% dos pacientes AF. RELATO: Lactente de 14 meses, sexo masculino, admitido para investigar um quadro de febre, hepatoesplenomegalia e granulopenia. Os exames laboratoriais mostraram a hiperferritemia, elevação da transaminases, medula óssea com hemofagocitose e, sorologia e PCR positivos para citomegalovírus (CMV). O paciente foi diagnosticado com síndrome hemofagocítica por citomegalovírus. Como havia também hipoplasia do polegar esquerdo, presença de hemivértebra, agenesia renal e teste positivo de fragilidades cromossômicas com mitomicina C (MMC), o paciente foi diagnosticado com associação VACTERL/AF. CONCLUSÃO: O citomegalovírus quando infecta pacientes com problemas de imunidade como AF, apresenta risco de desencadear a síndrome hemofagocítica. A associação VACTERL/AF é pouco descrita, mas presente na prática médica da pediatria. Esse estudo descreveu os principais aspectos clínicos-laboratoriais e revisou os aspectos fundamenais descritos sobre a concomitância dessas patologias.

Polymorphisms involved in folate metabolism pathways and the risk of the development of childhood acute leukemia.

OBJECTIVE: Polymorphisms that reduce the activity of reduced folate carrier (RFC) and methylenetetrahydrofolate reductase (MTHFR) and double (2R2R) or triple (3R3R) 28-bp tandem repeats in the promoter region of thymidylate synthase (TS) have been associated with the risk of childhood acute leukemia (AL). A case-control genotyping study was conducted in Brazilian children with the aim of investigating RFC, MTHFR, and TS polymorphisms as risk factors. METHODS: The polymerase chain reaction-restriction fragment length polymorphism method was employed in 177 AL cases and 390 controls. RESULTS: The presence of the mutant 1298C, also RFC 80A, was linked to a decreased risk of developing acute lymphoid leukemia (ALL) (odds ratio (OR)=0.46, 95% confidence interval (CI)=0.30-071 and OR=0.51, 95% CI=0.28-0.0.93, respectively). CONCLUSIONS: The genotype 677 CT was associated with increased risk of developing ALL (OR=1.6, 95% CI=1.1-2.7). Further epidemiological study is needed to unravel the role of complex multiple gene-environment interactions in leukemogenesis.

Extra Copies of der(21)t(12;21) plus Deletion of ETV6 Gene due to dic(12;18) in B-Cell Precursor ALL with Poor Outcome.

Acute lymphoblastic leukemia (ALL), CD10+ B-cell precursor, represents the most frequent type of childhood ALL from 3 to 6 years of age. The t(12;21)(p13;q22) occurs in 25% of cases of B-cell precursor ALL, it is rare in children less than 24 months and have been related to good prognosis. Some relapse cases and unfavorable prognosis in ALL CD10+ are associated with t(12;21) bearing additional aberrations as extra copies of chromosome 21 and ETV6 gene loss. This report describes the case of a 15 month-year old girl, who displayed a karyotype with addition on chromosome 12p plus trisomy 10 and tetrasomy of chromosome 21. Molecular cytogenetic studies revealed two extra copies of the der(21) t(12;21), trisomy 10 and deletion of the second ETV6 gene due to the dic(12;18). These findings show the great importance of molecular cytogenetic studies to clarify complex karyotypes, to define prognostic, to carry out risk group stratification and to support correctly disease treatment in childhood acute lymphoblastic leukemia.

Complex karyotype defined by molecular cytogenetic FISH and M-FISH in an infant with acute megakaryoblastic leukemia and neurofibromatosis.

Acute myeloid leukemia in childhood is a heterogeneous group of diseases, and different epidemiologic factors are involved in the etiopathogenesis. Genetic syndromes are one of the predisposing factors of acute myeloid leukemia (AML), including Down syndrome, Bloom syndrome, and neurofibromatosis. Acute megakaryoblastic leukemia (AMKL) is the main subtype in Down syndrome infants, and acquired chromosomal anomalies are closely related to the physiopathology of the illness. The main chromosomal anomalies in AMKL are structural, such as t(1;22); however, complex karyotypes are also common. Here we describe the case of an infant with neurofibromatosis developing AMKL with a complex karyotype including 5q and 17q deletions, TP53 deletion, and an unusual unbalanced chromosomal translocation t(11;19)(q13;p13), leading to three copies of the MLL gene.

Molecular cytogenetic studies characterize a near-triploid complex karyotype in a child with acute lymphoblastic leukemia.

High hyperdiploidy with modal chromosome numbers between 50 and 65 is common in childhood acute lymphoblastic leukemia (ALL), occurring in 25-30% of the cases. This chromosomal constitution is associated with a very good prognosis. By contrast, near triploidy and tetraploidy are found in <1% of childhood ALL. Given the sparseness of this group, the associated chromosomal abnormalities and their prognostic implications have not yet been studied in detail. Here, we describe clinical and molecular cytogenetic findings in a child with ALL who had a near-triploid complex karyotype, with loss and gain of chromosomes, including extra copies of the same derivative chromosomes. These findings suggest a random nondisjunction mechanism for near triploidy in the present case.

Myeloproliferative syndrome of monosomy 7: a brief report

We report the case of a five-month-old black male infant who had recurrent episodes of respiratory infections and also presented anemia and enlargements of the spleen, liver and lymphnodes. Hematological analysis revealed morphological abnormalities with megaloblastic dyserythropoiesis, while fetal hemoglobin assaying showed normal levels. Conventional and molecular cytogenetic analysis revealed monosomy of chromosome 7. Despite all therapeutic efforts during allogenic bone marrow transplantation, the child died due to generalized infection. The clinical and genetic distinctions between monosomy 7 syndrome and myelodysplastic disorders in childhood are discussed.

Association between the MTHFR A1298C polymorphism and increased risk of acute myeloid leukemia in Brazilian children.

Methylenetetrahydrofolate reductase (MTHFR) is an essential enzyme in the metabolism of folate. The presence of polymorphisms that reduce the activity of MTHFR has been linked to the multifactor process of development of acute leukemia. A case control study was conducted on Brazilian children in different regions of the country with the aim of investigating the role of MTHFR C677T and A1298C polymorphisms as risk factors in the development of acute myeloid leukemia (AML). We used the polymerase chain reaction restriction fragment length polymorphism method to genotyping 182 AML and 315 healthy individuals. The genotype 677 CT was associated with decreased risk [odds ratio (OR), 0.37; confidence interval (CI) 95%, 0.14 - 0.92], whereas 1298 AC genotype was linked with an increased risk [OR, 2.90; CI 95%, 1.26 - 6.71] of developing AML in non-white children. Further epidemiological study is needed to unravel the complex multiple gene-environment interactions in the role of the AML leukemogenesis.