Hemophagocytosis by blasts in a child with acute monocytic leukemia after chemotherapy / Hemofagocitose por células blásticas em paciente pediátrico com leucemia monocítica aguda após quimioterapia

ABSTRACT Objective: To describe the case of a child who presented hemophagocytic lymphohistiocytosis (HLH) associated with acute monocytic leukemia after chemotherapy, with hemophagocytosis caused by leukemic cells. Case description: In a university hospital in Southern Brazil, a 3-year-old female was diagnosed with acute monocytic leukemia with normal karyotype. The chemotherapy regimen was initiated, and she achieved complete remission six months later, relapsing after four months with a complex karyotype involving chromosomes 8p and 16q. The bone marrow showed vacuolated blasts with a monocytic aspect and evidence of hemophagocytosis. The child presented progressive clinical deterioration and died two months after the relapse. Comments: HLH is a rare and aggressive inflammatory condition characterized by cytopenias, hepatosplenomegaly, fever, and hemophagocytosis in the bone marrow, lymph nodes, spleen, and liver. Although rare, malignancy-associated HLH (M-HLH) is fatal. The patient in this case report met five out of the eight established criteria for HLH. The evolution of the patient's karyotype, regardless of the diagnostic profile, seemed secondary to the treatment for acute monocytic leukemia. In this case, the cytogenetic instability might have influenced the abnormal behavior of leukemic cells. This is a rare case of HLH in a child with acute monocytic leukemia.

RESUMO Objetivo: Descrever um caso de um paciente pediátrico que apresentou linfo-histiocitose hemofagocítica (LHH) associada à leucemia monocítica aguda pós-quimioterapia, com hemofagocitose causada pelas próprias células leucêmicas. Descrição do caso: Em um hospital universitário do Sul do Brasil, uma menina de três anos foi diagnosticada com leucemia monocítica aguda com cariótipo normal. Após receber protocolo quimioterápico, atingiu remissão seis meses depois do início do tratamento, recaíndo quatro meses após com um cariótipo complexo envolvendo ambos os cromossomos, 8p e 16q. A medula óssea mostrava-se infiltrada por células blásticas vacuolizadas com aspecto monocítico, com evidências de hemofagocitose. A criança apresentou um declínio clínico progressivo e dois meses após a recaída foi a óbito. Comentários: A LHH é uma condição inflamatória rara e agressiva caracterizada por citopenias, hepatoesplenomegalia, febre e hemofagocitose na medula óssea, linfonodos, baço e fígado. A LHH associada a doenças malignas, embora seja uma condição rara, é potencialmente fatal. A paciente deste caso apresentou cinco dos oito critérios estabelecidos para o diagnóstico de LHH. A evolução do cariótipo do paciente, independentemente do perfil do diagnóstico, pareceu ser secundária ao tratamento da leucemia monocítica aguda, sendo que a instabilidade citogenética pode ter influenciado o comportamento atípico observado nas células leucêmicas. Este é um dos raros casos de LHH em uma criança com leucemia monocítica aguda.

Relative frequency and estimated minimal frequency of Lysosomal Storage Diseases in Brazil: Report from a Reference Laboratory

Abstract Lysosomal storage diseases (LSDs) comprise a heterogeneous group of more than 50 genetic conditions of inborn errors of metabolism (IEM) caused by a defect in lysosomal function. Although there are screening tests for some of these conditions, diagnosis usually depends on specific enzyme assays, which are only available in a few laboratories around the world. A pioneer facility for the diagnosis of IEM and LSDs was established in the South of Brazil in 1982 and has served as a reference service since then. Over the past 34 years, samples from 72,797 patients were referred for investigation of IEM, and 3,211 were confirmed as having an LSD (4.41%, or 1 in 22), with 3,099 of these patients originating from Brazil. The rate of diagnosis has increased over time, in part due to the creation of diagnostic networks involving a large number of Brazilian services. These cases, referred from Brazilian regions, provide insight about the relative frequency of LSDs in the country. The large amount of data available allows for the estimation of the minimal frequency of specific LSDs in Brazil. The reported data could help to plan health care policies, as there are specific therapies available for most of the cases diagnosed.

Diabetes insipidus como manifestação inicial de leucemia mieloide aguda em paciente com monossomia do cromossomo 7 / Diabetes insipidus as initial manifestation of acute myeloid leukemia in a patient with monosomy of chromosome 7

O diabetes insipidus (DI) central é uma síndrome caracterizada pela incapacidade de concentração urinária devido à deficiência do hormônio antidiurético. O envolvimento do sistema nervoso central é frequente nas leucemias, mas a ocorrência de DI é rara e confere pior prognóstico. A patogênese do DI na leucemia não é totalmente conhecida, mas a infiltração do eixo hipotálamo-hipofisário por células leucêmicas parece ser um fator responsável. O presente relato descreve o caso de um paciente que apresentou DI como primeira manifestação de leucemia mieloide aguda e que evoluiu com dificuldades de ajustes do sódio sérico, da poliúria e da reposição volêmica, necessitando de permanência prolongada em unidade de cuidados intensivos(AU)

Central diabetes insipidus (DI) is a syndrome characterized by the inability to concentrate urine due to a lack of antidiuretic hormone. Involvement of the central nervous system is common in acute leukemia, but the occurrence of DI is rare and determines a worse prognosis. The pathogenesis of DI in leukemia has not been fully understood yet, but infiltration of the hypothalamic-pituitary axis by leukemic cells seems to be involved. This report describes a case of a patient who presented with DI as the first manifestation of acute myeloid leukemia. Difficulties in the management of serum sodium, fluid replacement and polyuria led to prolonged length of stay in an intensive care unit(AU)

Análise comparativa entre as metodologias de PCR metilação-específica (MSP), southern blot (SB) e FISH utilizadas no diagnóstico genético molecular de pacientes com suspeita clínica das síndromes de Prader-Willi ou Angelman / Comparative analysis of methylation-specific PCR (MSP), southern blot (SB) and FISH in molecular genetic diagnosis of patients with clinical picture suggestive of Prader-Willi or Angelman syndromes

Introdução: Prader-Willi (SPW) e Angelman (SA) são síndromes clinicamente distintas, causadas pela perda de expressão de genes na região cromossômica 15q11.2-q13, de origem paterna ou materna, respectivamente. Ambas compartilham os mesmos métodos diagnósticos. Nossos objetivos foram: a) analisar por PCR metilação-específica (MSP) pacientes com suspeita clínica de SPW/SA; b) comparar resultados de diferentes metodologias de diagnóstico molecular; c) aplicar a técnica MSP na rotina assistencial de pacientes encaminhados ao Serviço de Genética Médica/Hospital de Clínicas de Porto Alegre (SGM/HCPA). Métodos: Foram analisados 123 pacientes com suspeita clínica de SPW (n = 71) ou SA (n = 52) por MSP. Desses, 79 possuíam análise prévia por hibridação in situ fluorescente (FISH) e/ou Southern blot (SB). Resultados: Foram detectados 21 casos positivos – 15 de SPW (12,19%) e 6 de SA (4,88%). Nove pacientes tiveram etiologia molecular determinada, sendo sete com diagnóstico de SPW (quatro dissomias uniparentais – UPD15 materna – e três deleções na região 15q11-13) e dois com diagnóstico de SA (um com UPD15 paterna e um com deleção na região 15q11-13). Foram observados resultados equivalentes entre MSP e SB e resultados discrepantes entre MSP e FISH (n = 4). Foram padronizados dois protocolos de MSP para confirmação dos resultados e controle interno de qualidade. Conclusão: O perfil de detecção de cada técnica varia de acordo com o mecanismo etiológico presente. A análise por MSP detecta alterações no padrão de metilação geradas por deleção, UPD e defeitos de imprinting, sem identificar o mecanismo etiológico responsável...

Introduction: Prader-Willi (PWS) and Angelman (AS) are clinically different syndromes caused by loss of expression of genes located on the chromosome 15q11.2-q13, of paternal or maternal origin, respectively. Both syndromes have the same diagnostic methods. The aims of the present study were: a) to perform a molecular analysis of 123 patients with clinical findings suggestive of PWS or AS using methylation-specific PCR (MSP); b) to compare the results obtained using different molecular diagnostic methodologies; c) to standardize MSP to be used in the routine care of patients at Medical Genetics Service/Hospital de Clínicas de Porto Alegre (SGM/HCPA). Methods: 123 patients with clinical findings suggestive of PWS (n = 71) or AS (n = 52) were analyzed by MSP. 79 had undergone previous laboratory analysis by fluorescence in situ hybridization (FISH) and/or Southern blot (SB). Results: MSP detected 21 positive cases – 15 PWS (12,19%) and 6 AS (4,88%). Molecular etiology was determined in 9 patients only – 7 were diagnosed with PWS (4 had uniparental disomy – maternal UPD15 – and 3 had deletions at 15q11-13) and 2 were diagnosed with AS (1 of paternal UPD15 and 1 deletion at 15q11-13). Comparing both methodologies, it was possible to observe concordant results between MSP and SB and discordant results between MSP and FISH (n = 4). We standardized two MSP methods in order to confirm the results and for internal quality control. Conclusion: The resulting profile of each technique varies according to the existing etiological mechanism. The methylation analysis by MSP technique detects changes on methylation pattern caused by deletion, UPD and imprinting defects, but it does not identify the responsible etiologic mechanism...

Microarray-based comparative genomic hybridization analysis in neonates with congenital anomalies: detection of chromosomal imbalances / Hibridização genômica comparativa baseada em microarranjos em neonatos com anomalias congênitas: detecção de desequilíbrios cromossômicos

OBJECTIVE: To identify chromosomal imbalances by whole-genome microarray-based comparative genomic hybridization (array-CGH) in DNA samples of neonates with congenital anomalies of unknown cause from a birth defects monitoring program at a public maternity hospital. METHODS: A blind genomic analysis was performed retrospectively in 35 stored DNA samples of neonates born between July of 2011 and December of 2012. All potential DNA copy number variations detected (CNVs) were matched with those reported in public genomic databases, and their clinical significance was evaluated. RESULTS: Out of a total of 35 samples tested, 13 genomic imbalances were detected in 12/35 cases (34.3%). In 4/35 cases (11.4%), chromosomal imbalances could be defined as pathogenic; in 5/35 (14.3%) cases, DNA CNVs of uncertain clinical significance were identified; and in 4/35 cases (11.4%), normal variants were detected. Among the four cases with results considered causally related to the clinical findings, two of the four (50%) showed causative alterations already associated with well-defined microdeletion syndromes. In two of the four samples (50%), the chromosomal imbalances found, although predicted as pathogenic, had not been previously associated with recognized clinical entities. CONCLUSIONS: Array-CGH analysis allowed for a higher rate of detection of chromosomal anomalies, and this determination is especially valuable in neonates with congenital anomalies of unknown etiology, or in cases in which karyotype results cannot be obtained. Moreover, although the interpretation of the results must be refined, this method is a robust and precise tool that can be used in the first-line investigation of congenital anomalies, and should be considered for prospective/retrospective analyses of DNA samples by birth defect monitoring programs. .

OBJETIVO: Identificar desequilíbrios cromossômicos por meio da hibridização genômica comparativa baseada em microarranjos (CGH-array) em amostras de DNA de neonatos com anomalias congênitas de causa desconhecida de um programa de monitoramento de defeitos congênitos em uma maternidade pública. MÉTODOS: Uma análise genômica cega foi realizada retrospectivamente em 35 amostras armazenadas de DNA de neonatos nascidos entre julho de 2011 e dezembro de 2012. Todas as possíveis variações no número de cópias (CNVs) de DNA foram comparadas com as relatadas em bases de dados genômicos públicas, e sua relevância clínica foi avaliada. RESULTADOS: De um total de 35 amostras testadas, foram detectados 13 desequilíbrios genômicos em 12/35 casos (34,3%). Em 4/35 casos (11,4%), os desequilíbrios cromossômicos poderiam ser definidos como patogênicos; em 5/35 (14,3%) deles foram identificadas CNVs de DNA de relevância clínica incerta; e, em 4/35 (11,4%), foram detectadas variações normais. Dentre os quatro casos com resultados considerados relacionados causalmente aos achados clínicos, 2/4 (50%) apresentaram alterações causais já relacionadas a síndromes de microdeleção bem definidas. Em 2/4 amostras (50%), os desequilíbrios cromossômicos encontrados, embora preditivos como patogênicos, não estavam relacionados anteriormente a entidades clínicas reconhecidas. CONCLUSÕES: A análise de CGH-array permitiu maior taxa de detecção de anomalias cromossômicas, e essa determinação é valiosa principalmente em neonatos com anomalias congênitas de etiologia desconhecida ou em casos em que os resultados do cariótipo não podem ser obtidos. Além disso, embora a interpretação dos resultados deva ser refinada, esse método é uma ferramenta robusta e precisa que pode ser usada na investigação de primeira linha de anomalias congênitas e deve ser considerada em análises futuras/retrospectivas de amostras de DNA por programas de monitoramento de defeitos congênitos. .

Molecular cytogenetic evaluation of chromosomal microdeletions: the experience of a public hospital in Southern Brazil

Introduction: During the past few decades, the number of diseases identified to be caused by chromosomal microdeletions has increased quickly, bringing a new and crucial role for cytogenetics on the diagnosis of these conditions. The purpose of this study was to identify and characterize chromosomal microdeletions associated with malformation syndromes and intellectual disability. Methods: We retrospectively evaluated a consecutive series of samples from a cohort of 598 subjects with clinical symptoms of a microdeletion syndrome, including the deletion of chromosomes 4p16.3, 5p15.2, 5q35, 7q11.23, 8q24.12, 15q11.2, 16p13.3, 17p13.3, 17p11.2,2, and 22q11.2, as investigated by fluorescence in situ hybridization (FISH). Array-based comparative genomic hybridization (array-CGH) was performed on 25 samples with microdeletions. Results: A total of 598 samples were evaluated from patients whose clinical phenotypes were most indicative of 22q11.2 deletion syndrome (29.10%), Prader-Willi syndrome (23.41%), Angelman syndrome (16.89%), and Williams-Beuren syndrome (14.72%). In 142 of the samples (23.75%), a chromosomal imbalance associated with phenotypic abnormalities was found. The deletion of 7q11.23 was the most frequent (8.03%), followed by del22q11.2 (5.68%) and del15q11.2 (5%). Conclusion: Our study reinforces the idea that the effort to improve the capacity to perform molecular cytogenetic investigations associated with a qualified clinical evaluation is crucial for the detection and precise characterization of submicroscopic chromosome deletions, bringing benefits to patients, relatives, and genetic counselors. It also contributes to the continuing education of cytogeneticists and to the knowledge of chromosomal rearrangements associated with genomic disorders.

A further case of a Prader-Willi syndrome phenotype in a patient with Angelman syndrome molecular defect

Angelman syndrome (AS) and Prader-Willi syndrome (PWS) are distinct human neurogenetic disorders; however, a clinical overlap between AS and PWS has been identified. We report on a further case of a patient showing the PWS phenotype with the AS molecular defect. Despite the PWS phenotype, the DNA methylation analysis of SNRPN revealed an AS pattern. Cytogenetic and FISH analysis showed normal chromosomes 15 and microsatellite analysis showed heterozygous loci inside and outside the 15q11-13 region. The presence of these atypical cases could be more frequent than previously expected and we reinforce that the DNA methylation analysis is important for the correct diagnosis of severe mental deficiency, congenital hypotonia and obesity