invdup(8)(8q24.13q24.3)-A Complex Alteration and Its Clinical Consequences.

Structural variation is a source of genetic variation that, in some cases, may trigger pathogenicity. Here, we describe two cases, a mother and son, with the same partial inverted duplication of the long arm of chromosome 8 [invdup(8)(q24.21q24.21)] of 17.18 Mb, showing different clinical manifestations: microcephaly, dorsal hypertrichosis, seizures and neuropsychomotor development delay in the child, and a cleft lip/palate, down-slanted palpebral fissures and learning disabilities in the mother. The deleterious outcome, in general, is reflected by the gain or loss of genetic material. However, discrepancies among the clinical manifestations raise some concerns about the genomic configuration within the chromosome and other genetic modifiers. With that in mind, we also performed a literature review of research published in the last 20 years about the duplication of the same, or close, chromosome region, seeking the elucidation of at least some relevant clinical features.

A child with cat-eye syndrome and oculo-auriculo-vertebral spectrum phenotype: A discussion around molecular cytogenetic findings.

Cat eye syndrome (CES) is a rare chromosomal disorder that may be evident at birth. A small supernumerary chromosome is present, frequently has 2 centromeres, is bisatellited, and represents an inv dup(22)(q11) in those affected. It's known that the 22q11 region is associated with disorders involving higher and lower gene dosages. Conditions such as CES, 22q11 microduplication syndrome (Dup22q11) and oculoauriculovertebral spectrum phenotype (OAVS) may share genes belonging to this same region, which is known to have a predisposition to chromosomal rearrangements. The conditions, besides being related to chromosome 22, also share similar phenotypes. Here we have added a molecular evaluation update and results found of the first patient described with CES and OAVS phenotype, trying to explain the potential mechanism involved in the occurrence of this association.

Spontaneous Pubertal Onset in a Male Patient With Mixed Gonadal Dysgenesis With Mosaicism 45,X/ 46, X, mar (Y)/ 47,X,mar(Y),+mar(Y) - Pediatric Case Report.

This report describes an adolescent with Mixed Gonadal Dysgenesis and unexpected mosaicism [karyotype 46,X,mar(Y)/ 47,X, mar(Y),+mar(Y)].). Diagnosis with 1 month of age due to atypical genitalia. He presented a right streak gonad, which was removed due to the risk for germ cell tumor, and a left testis with epididymis barely connected and without vas deferens. Left testis maintenance was sufficient for him to undergo spontaneous puberty. The patient was non-responsive to growth hormone. Webbed neck was the only dysmorphic feature. To the best of our knowledge, there were no similar cases reported with spontaneous pubertal progress reported in the literature.

Shared Neurodevelopmental Perturbations Can Lead to Intellectual Disability in Individuals with Distinct Rare Chromosome Duplications.

Chromosomal duplications are associated with a large group of human diseases that arise mainly from dosage imbalance of genes within the rearrangements. Phenotypes range widely but are often associated with global development delay, intellectual disability, autism spectrum disorders, and multiple congenital abnormalities. How different contiguous genes from a duplicated genomic region interact and dynamically affect the expression of each other remains unclear in most cases. Here, we report a genomic comparative delineation of genes located in duplicated chromosomal regions 8q24.13q24.3, 18p11.32p11.21, and Xq22.3q27.2 in three patients followed up at our genetics service who has the intellectual disability (ID) as a common phenotype. We integrated several genomic data levels by identification of gene content within the duplications, protein-protein interactions, and functional analysis on specific tissues. We found functional relationships among genes from three different duplicated chromosomal regions, reflecting interactions of protein-coding genes and their involvement in common cellular subnetworks. Furthermore, the sharing of common significant biological processes associated with ID has been demonstrated between proteins from the different chromosomal regions. Finally, we elaborated a shared model of pathways directly or indirectly related to the central nervous system (CNS), which could perturb cognitive function and lead to ID in the three duplication conditions.

Network-based analysis using chromosomal microdeletion syndromes as a model.

Microdeletion syndromes (MSs) are a heterogeneous group of genetic diseases that can virtually affect all functions and organs in humans. Although systems biology approaches integrating multiomics and database information into biological networks have expanded our knowledge of genetic disorders, cytogenomic network-based analysis has rarely been applied to study MSs. In this study, we analyzed data of 28 MSs, using network-based approaches, to investigate the associations between the critical chromosome regions and the respective underlying biological network systems. We identified MSs-associated proteins that were organized in a network of linked modules within the human interactome. Certain MSs formed highly interlinked self-contained disease modules. Furthermore, we observed disease modules involving proteins from other disease groups in the MSs interactome. Moreover, analysis of integrated data from 564 genes located in known chromosomal critical regions, including those contributing to topological parameters, shared pathways, and gene-disease associations, indicated that complex biological systems and cellular networks may underlie many genotype to phenotype associations in MSs. In conclusion, we used a network-based analysis to provide resources that may contribute to better understanding of the molecular pathways involved in MSs.

HEMOPHAGOCYTOSIS BY BLASTS IN A CHILD WITH ACUTE MONOCYTIC LEUKEMIA AFTER CHEMOTHERAPY.

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.

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.

Candidate Genes Associated With Neurological Findings in a Patient With Trisomy 4p16.3 and Monosomy 5p15.2.

In this report, we present a patient with brain alterations and dysmorphic features associated with chromosome duplication seen in 4p16.3 region and chromosomal deletion in a critical region responsible for Cri-du-chat syndrome (CdCS). Chromosomal microarray analysis (CMA) revealed a 41.1 Mb duplication encompassing the band region 4p16.3-p13, and a 14.7 Mb deletion located between the bands 5p15.33 and p15.1. The patient's clinical findings overlap with previously reported cases of chromosome 4p duplication syndrome and CdCS. The patient's symptoms are notably similar to those of CdCS patients as she presented with a weak, high-pitched voice and showed a similar pathogenicity observed in the brain MRI. These contiguous gene syndromes present with distinct clinical manifestations. However, the phenotypic and cytogenetic variability in affected individuals, such as the low frequency and the large genomic regions that can be altered, make it challenging to identify candidate genes that contribute to the pathogenesis of these syndromes. Therefore, systems biology and CMA techniques were used to investigate the extent of chromosome rearrangement on critical regions in our patient's phenotype. We identified the candidate genes PPARGC1A, CTBP1, TRIO, TERT, and CCT5 that are associated with the neuropsychomotor delay, microcephaly, and neurological alterations found in our patient. Through investigating pathways that associate with essential nodes in the protein interaction network, we discovered proteins involved in cellular differentiation and proliferation, as well as proteins involved in the formation and disposition of the cytoskeleton. The combination of our cytogenomic and bioinformatic analysis provided these possible explanations for the unique clinical phenotype, which has not yet been described in scientific literature.

Candidate Genes Associated with Delayed Neuropsychomotor Development and Seizures in a Patient with Ring Chromosome 20.

Ring chromosome 20 (r20) is characterized by intellectual impairment, behavioral disorders, and refractory epilepsy. We report a patient presenting nonmosaic ring chromosome 20 followed by duplication and deletion in 20q13.33 with seizures, delayed neuropsychomotor development and language, mild hypotonia, low weight gain, and cognitive deficit. Chromosomal microarray analysis (CMA) enabled us to restrict a chromosomal segment and thus integrate clinical and molecular data with systems biology. With this approach, we were able to identify candidate genes that may help to explain the consequences of deletions in 20q13.33. In our analysis, we observed five hubs (ARFGAP1, HELZ2, COL9A3, PTK6, and EEF1A2), seven bottlenecks (CHRNA4, ARFRP1, GID8, COL9A3, PTK6, ZBTB46, and SRMS), and two H-B nodes (PTK6 and COL9A3). The candidate genes may play an important role in the developmental delay and seizures observed in r20 patients. Gene ontology included microtubule-based movement, nucleosome assembly, DNA repair, and cholinergic synaptic transmission. Defects in these bioprocesses are associated with the development of neurological diseases, intellectual disability, neuropathies, and seizures. Therefore, in this study, we can explore molecular cytogenetic data, identify proteins through network analysis of protein-protein interactions, and identify new candidate genes associated with the main clinical findings in patients with 20q13.33 deletions.

Clinical findings in Brazilian patients with adult GM1 gangliosidosis.

GM1 gangliosidosis is a lysosomal storage disorder caused by ß-galactosidase deficiency. To date, prospective studies for GM1 gangliosidosis are not available, and only a few have focused on the adult form. This retrospective cross-sectional study focused on clinical findings in Brazilian patients with the adult form of GM1 gangliosidosis collected over 2 years. Ten subjects were included in the study. Eight were males and two females, with median age at diagnosis of 11.5 years (IQR, 4-34 years). Short stature and weight below normal were seen in five out of the six patients with data available. Radiological findings revealed that the most frequent skeletal abnormalities were beaked vertebrae, followed by hip dysplasia, and platyspondyly. Neurological examination revealed that dystonia and swallowing problems were the most frequently reported. None of the patients presented hyperkinesia, truncal hypertonia, Parkinsonism, or spinal cord compression. Clinical evaluation revealed impairment in activities of cognitive/intellectual development and behavioral/psychiatric disorders in all nine subjects with data available. Language/speech impairment (dysarthria) was found in 8/9 patients, fine motor and gross motor impairments were reported in 7/9 and 5/9 patients, respectively. Impairment of cognition and daily life activities were seen in 7/9 individuals. Our findings failed to clearly identify typical early or late alterations presented in GM1 gangliosidosis patients, which confirms that it is a very heterogeneous condition with wide phenotypic variability. This should be taken into account in the evaluation of future therapies for this challenging condition.

Information and Diagnosis Networks - tools to improve diagnosis and treatment for patients with rare genetic diseases.

Brazil is a country of continental dimensions and most genetic services are concentrated in the Southeast and South, including the Medical Genetics Service of the Hospital de Clínicas de Porto Alegre (MGS/HCPA). As many areas on the country do not have adequate medical genetics support, networks were designed to extend the service of the MGS/HCPA reference center. This paper presents the information and diagnosis networks that have their headquarters at MGS/HCPA: SIAT (National Information System on Teratogenic Agents), SIEM (Information Service on Inborn Errors of Metabolism), Alô Genética (Hello Genetics - Medical Genetics Information Service for Primary Health Care Professionals); Rede MPS Brasil (MPS-Mucopolysaccharidosis Brazil Network); Rede EIM Brasil (IEM-Inborn Errors of Metabolism Brazil Network), Rede NPC Brasil (Niemann-Pick C - NPC Brazil Network), Rede DLD Brasil (LSD-Lysosomal Storage Disorders Brazil Network), Rede DXB (MSUD-Maple Syrup Urine Disease Network), RedeBRIM (Brazilian Network of Reference and Information in Microdeletion Syndromes Project), Rede Neurogenética (Neurogenetics Network), and Rede Brasileira de Câncer Hereditário (Brazilian Hereditary Cancer Network). These tools are very useful to provide access to a qualified information and/or diagnostic service for specialized and non-specialized health services, bypassing difficulties that preclude patients to access reference centers.

Analysis of a Protein Network Related to Copy Number Variations in Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder, with strong genetic influences as evidenced by its high heritability. Submicroscopic variations (ranging from one kilobase to several megabases) in DNA, called copy number variations (CNVs), have been associated with psychiatric diseases, including ASD. We aimed to identify CNVs in children diagnosed with idiopathic ASD. We used microarray-based comparative genomic hybridization analysis to detect the CNVs, and bioinformatic tools to evaluate their pathogenic potential, based on predicted functional aspects. Using combined cytogenetic and bioinformatic tools, we identified an autism network of genes/proteins related to the CNVs. Among the 40 children analyzed, we found 14 potentially pathogenic CNVs, including those previously associated with ASD (located at 16p11.2, 15q11.2, and 7p21 regions). We suggest that the most relevant biological process and functional attributes involve olfactory receptors. The CNV-related autism network comprised 90 proteins and 754 nodes and indicated the family of olfactory receptors as a significant pathway in ASD. Olfactory receptors were previously associated with neurologic diseases, and they are possibly related to cognition. This integrative analysis that combines cytogenetics and bioinformatics is a promising approach to understand complex conditions such as ASD.

Population medical genetics: translating science to the community.

Rare genetic disorders are currently in the spotlight due to the elevated number of different conditions and significant total number of affected patients. The study of these disorders is extremely helpful for the elucidation of physiological processes related with complex disorders. Isolated populations are instrumental for the study of genetic disorders, considering their homogeneity and high proportion of affected patients in a small geographic area. These favorable conditions lead to the creation of a new discipline, known as "population medical genetics", which integrates medical genetics, population genetics, epidemiological genetics and community genetics. In order to develop practical activities in this new discipline, the National Institute of Population Medical Genetics (INaGeMP) was created in 2008 in Brazil. INaGeMP has developed several tools and funded numerous research activities. In this review, we highlight three successful projects developed in the first 10 years of INaGeMP activities (2008-2018): a newborn screening pilot study for MPS VI in Northeast Brazil, the study of Machado-Joseph disease in Brazilian families with Azorian ancestry, and the high twinning rate in a small town in southern Brazil. The results of these projects in terms of scientific output and contributions to the affected communities highlight the success and importance of INaGeMP.

Integrated analysis of the critical region 5p15.3-p15.2 associated with cri-du-chat syndrome.

Cri-du-chat syndrome (CdCs) is one of the most common contiguous gene syndromes, with an incidence of 1:15,000 to 1:50,000 live births. To better understand the etiology of CdCs at the molecular level, we investigated theprotein-protein interaction (PPI) network within the critical chromosomal region 5p15.3-p15.2 associated with CdCs using systemsbiology. Data were extracted from cytogenomic findings from patients with CdCs. Based on clinical findings, molecular characterization of chromosomal rearrangements, and systems biology data, we explored possible genotype-phenotype correlations involving biological processes connected with CdCs candidate genes. We identified biological processes involving genes previously found to be associated with CdCs, such as TERT, SLC6A3, and CTDNND2, as well as novel candidate proteins with potential contributions to CdCs phenotypes, including CCT5, TPPP, MED10, ADCY2, MTRR, CEP72, NDUFS6, and MRPL36. Although further functional analyses of these proteins are required, we identified candidate proteins for the development of new multi-target genetic editing tools to study CdCs. Further research may confirm those that are directly involved in the development of CdCs phenotypes and improve our understanding of CdCs-associated molecular mechanisms.

Towards New Approaches to Evaluate Dynamic Mosaicism in Ring Chromosome 13 Syndrome.

Individuals with ring chromosome 13 may show characteristics observed in a deletion syndrome and could present a set of dismorphies along with intellectual disability, according to chromosomal segments involved in the genetic imbalance. Nevertheless, ring anomalies likewise is called "dynamic mosaicism", phenomena triggered by the inner instability concerning the ring structure, thus leading to the establishment of different cell clones with secondary aberrations. Phenotypic features, such as growth failure and other anomalies in patients with this condition have been associated with an inherent ring chromosome mitotic instability, while recent studies offer evidence on a role played by the differential loss of genes implicated in development. Here, we observed similar mosaicism rates and specific gene loss profile among three individuals with ring chromosome 13 using GTW-banding karyotype analyses along with FISH and CGH-array approaches. Karyotypes results were: patient 1-r(13)(p13q32.3), patient 2-r(13)(p11q33.3), and patient 3-r(13)(p12q31.1). Array-CGH has revealed qualitative genetic differences among patients in this study and it was elusive in precise chromosomal loss statement, ranging from 13 Mb, 6.8 Mb, and 30 Mb in size. MIR17HG and ZIC2 loss was observed in a patient with digital anomalies, severe growth failure, microcephaly and corpus callosum agenesis while hemizygotic EFNB2 gene loss was identified in two patients, one of them with microphtalmia. According to these findings, it can be concluded that specific hemizygotic loss of genes related to development, more than dynamic mosaicism, may be causative of congenital anomalies shown in patients with ring 13 chromosome.

Cytogenomic Integrative Network Analysis of the Critical Region Associated with Wolf-Hirschhorn Syndrome.

Deletions in the 4p16.3 region are associated with Wolf-Hirschhorn syndrome (WHS), a contiguous gene deletion syndrome involving variable size deletions. In this study, we perform a cytogenomic integrative analysis combining classical cytogenetic methods, fluorescence in situ hybridization (FISH), chromosomal microarray analysis (CMA), and systems biology strategies, to establish the cytogenomic profile involving the 4p16.3 critical region and suggest WHS-related intracellular cell signaling cascades. The cytogenetic and clinical patient profiles were evaluated. We characterized 12 terminal deletions, one interstitial deletion, two ring chromosomes, and one classical translocation 4;8. CMA allowed delineation of the deletions, which ranged from 3.7 to 25.6 Mb with breakpoints from 4p16.3 to 4p15.33. Furthermore, the smallest region of overlapping (SRO) encompassed seven genes in a terminal region of 330 kb in the 4p16.3 region, suggesting a region of susceptibility to convulsions and microcephaly. Therefore, molecular interaction networks and topological analysis were performed to understand these WHS-related symptoms. Our results suggest that specific cell signaling pathways including dopamine receptor, NAD+ nucleosidase activity, and fibroblast growth factor-activated receptor activity are associated with the diverse pathological WHS phenotypes and their symptoms. Additionally, we identified 29 hub-bottlenecks (H-B) nodes with a major role in WHS.

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

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.

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)

Intellectual Disability in a Birth Cohort: Prevalence, Etiology, and Determinants at the Age of 4 Years.

BACKGROUND: Intellectual disability (ID), characterized by impairments in intellectual function and adaptive behavior, affects 1-3% of the population. Many studies investigated its etiology, but few are cohort studies in middle-income countries. AIMS: To estimate prevalence, etiology, and factors related to ID among children prospectively followed since birth in a Southern Brazilian city (Pelotas). METHODS: In 2004, maternity hospitals were visited daily and births were identified. Live-born infants (n = 4,231) whose family lived in the urban area have been followed for several years. At the age of 2 and 4 years, performances in development and intelligence tests were evaluated using the Battelle Developmental Inventory and Wechsler Intelligence Scale, respectively. Children considered as having developmental delay were invited to attend a genetic evaluation. RESULTS: At 4 years of age, the prevalence of ID was 4.5%, and the etiology was classified into 5 groups: environmental (44.4%), genetic (20.5%), idiopathic (12.6%), neonatal sequelae (13.2%), other diseases (9.3%). Most children presented impairment in two or more areas of adaptive behavior. There was no difference in prenatal care attendance or maternal schooling among the groups. CONCLUSION: For about 40% of children, ID was attributed to nonbiological factors, suggesting that the rate may be reduced with appropriate interventions early in life.