Síndrome de deleção 6q: relato de caso de um achado raro no Amazonas, Brasil / Deletion 6q syndrome: case report of a rare finding in Amazonas, Brazil

Objetivos: Síndrome da deleção 6q é considerada uma anomalia cromossômica rara. Assim, nosso objetivo foi relatar um caso de um menino com essa síndrome, em Manaus/Amazonas. Descrição do caso: Menino com quatro anos de idade que apresenta atraso do crescimento e do desenvolvimento neuropsicomotor, dificuldades de ganho de peso e anormalidades na retina. A análise citogenética do paciente revelou cariótipo com 46, XY, del(6)(q25-qter). Conclusões: Este relato demonstrou a importância das análises citogenéticas para o diagnóstico preciso das anomalias congênitas, pois auxiliam no encaminhamento de tratamentos adequados aos pacientes e na ampliação de conhecimento científico relacionado a essa deleção.

Aims: Deletion 6q syndrome is considered a rare chromosomal anomaly. Thus, our objective was to report a rare case of a boy with 6q deletion syndrome. Case description: 4-year-old boy with delayed growth and neuropsychomotor development, weight gain difficulties and retinal abnormalities. Karyotypic analysis of the patient revealed karyotype 46, XY, del (6) (q25-qter). That is, a deletion in the long arm of one of the chromosome 6, specifically in the distal region of the long arm of the 6q25 band up to the 6qter band. Conclusions: This report demonstrates the importance of cytogenetic analyzes for the accurate diagnosis of congenital anomalies, as they assist in referring appropriate treatments to patients and in expanding scientific knowledge related to this deletion.

Investigation of chromosomal alterations in patients with Alzheimer's disease in the state of Amazonas, Brazil / Investigação de alterações cromossômicas em pacientes com doença de Alzheimer no estado do Amazonas, Brasil

ABSTRACT Alzheimer's disease (AD) has as its main characteristic the deterioration of cerebral functions. Its etiology is still complex and undefined despite the progress made in understanding its neurological, infectious, biochemical, genetic and cytogenetic mechanisms. Considering this, the aim of this study was to investigate the presence of chromosomal alterations in the peripheral blood lymphocytes, and to verify if there was a high frequency of these alterations in patients diagnosed with AD at the University Hospital GetúLio Vargas Outpatient Clinic Araújo Lima in Manaus, Amazonas, Brazil. Among the nine patients in the AD group, only one patient did not have metaphases with chromosomal alterations (2n = 46,XX), while eight patients with AD showed numerical chromosomal alterations, classified as X chromosome aneupLoidy (2n = 45,X) and double aneupLoidy (2n = 44,X,-X,-10; 2n = 44,X,-X,-13 and 2n = 44,X,-X,-21). In the control group, no chromosomal changes were found in the karyotypes of these individuals. Therefore, the karyotypes of patients with AD undergo chromosomal alterations at different levels. These findings are being described for the first time in the population of Amazonas, and they highlight the importance of the inclusion of cytogenetic investigations in the routine management of patients with AD.

RESUMO Doença de Alzheimer (DA) tem como principal característica a deterioração das funções cerebrais. Quanto a sua etiologia ainda é complexa e indefinida, apesar do progresso alcançado na compreensão de seus mecanismos neurológicos, infecciosos, bioquímicos, genéticos e citogenéticos. Considerando isto, nós investigamos a presença de alterações cromossômicas nos Linfócitos de sangue periférico e verificamos se há uma alta frequência dessas alterações em pacientes já diagnosticados com doença de Alzheimer no Hospital Universitário Getulio Vargas / Ambulatório Araújo Lima, Manaus / Amazonas / Brasil. Assim, dos 09 pacientes do grupo DA, somente 01 paciente não apresentou metáfases com alterações cromossômicas (2n = 46,XX) enquanto que 08 pacientes com DA apresentaram alterações cromossômicas numéricas, sendo classificadas como aneupLoidia do cromossomo X (2n = 45,X) e aneupLoidia dupLa (2n = 44,X,-X,-10; 2n = 44,X,-X,-13 e 2n = 44,X,-X,-21). No grupo controle, não foram encontradas aLterações cromossômicas nos cariótipos desses indivíduos. Estes achados para a popuLação do Amazonas/ BrasiL estão sendo descritos pela primeira vez. Os cariótipos de pacientes com DA sofrem aLterações cromossômicas em diferentes níveis e demonstraram a importância das investigações citogenéticas no manejo rotineiro de pacientes com DA.

Investigation of chromosomal alterations in patients with Alzheimer's disease in the state of Amazonas, Brazil.

OBJECTIVES: Alzheimer's disease (AD) has as its main characteristic the deterioration of cerebral functions. Its etiology is still complex and undefined despite the progress made in understanding its neurological, infectious, biochemical, genetic and cytogenetic mechanisms. METHODS: Considering this, the aim of this study was to investigate the presence of chromosomal alterations in the peripheral blood lymphocytes, and to verify if there was a high frequency of these alterations in patients diagnosed with AD at the University Hospital GetúLio Vargas Outpatient Clinic Araújo Lima in Manaus, Amazonas, Brazil. RESULTS: Among the nine patients in the AD group, only one patient did not have metaphases with chromosomal alterations (2n = 46,XX), while eight patients with AD showed numerical chromosomal alterations, classified as X chromosome aneupLoidy (2n = 45,X) and double aneupLoidy (2n = 44,X,-X,-10; 2n = 44,X,-X,-13 and 2n = 44,X,-X,-21). CONCLUSION: In the control group, no chromosomal changes were found in the karyotypes of these individuals. Therefore, the karyotypes of patients with AD undergo chromosomal alterations at different levels. These findings are being described for the first time in the population of Amazonas, and they highlight the importance of the inclusion of cytogenetic investigations in the routine management of patients with AD.

Concomitance of numerical chromosomal alterations with structural in an elderly with Alzheimer's disease: a case report / Concomitância de alterações cromossômicas numéricas com estruturais em idoso com doença de Alzheimer: relato de caso

AIMS: To report the first case the concomitance of numerical chromosomal abnormalities with structural as well as chromosomal abnormalities structural in a patient diagnosed with Alzheimer disease in Manaus/Amazonas. CASE DESCRIPTION: A male patient with 76 years of age was diagnosed with diagnosis of cognitive disorder- Alzheimer's disease with late onset - temporal variant after laboratory, physical and imaging exams. Cytogenetic analysis was requested for this patient, revealing the presence the concomitant of numerical and structural chromosomal abnormalities with metaphase cells composed of 45 chromosomes with the loss of one of the homologues of chromosome 21 (monosomy) and a deletion of the long arm of one of the homologues of chromosome 1 [45, XY, -21, del (1) (q?)] and metaphase cells containing 46 chromosomes with a deletion of the long arm of one of the homologues of chromosome 15 [(46, XY, del (15) (q?)]. Currently, the patient is in outpatient treatment for maintenance and control of the disease. CONCLUSIONS: Our study has underlined that karyotyping is one of the fundamental investigations for patients with Alzheimer's disease. It highlighted, in the form of a chromosomal abnormality, may have been the risk factor in Alzheimer's disease.

OBJETIVOS: Relatar o primeiro caso de concomitância de anormalidade cromossômica numérica com anormalidade cromossômica estruturais em um paciente diagnosticado com doença de Alzheimer em Manaus/Amazonas DESCRIÇÃO DO CASO: Um paciente do sexo masculino com 76 anos de idade foi diagnosticado com distúrbio cognitivo - doença de Alzheimer com início tardio - variante temporal, após exames laboratoriais, físicos e de imagem. Análises citogenéticas foi solicitado para esse paciente, revelando a presença concomitante de anormalidades cromossômicas numéricas e estruturais com células metafásicas compostas por 45 cromossomos, com a perda de um dos homólogos do cromossomo 21 (monossomia) e a deleção do braço longo de um dos homólogos do cromossomo 1 [45, XY, -21, del (1) (q?)] e células metafásicas contendo 46 cromossomos apresentando deleção no braço longo de um dos homólogos do cromossomo 15 [(46, XY, del (15) (q?)] Atualmente, o paciente encontra-se em tratamento ambulatorial para manutenção e controle da doença. CONCLUSÕES: Nosso estudo revelam que a cariotipagem é uma das investigações fundamentais para pacientes com doença de Alzheimer. A anormalidade cromossômicas pode ter sido o fator de risco para a doença de Alzheimer.

DNA barcoding in pencilfishes (Lebiasinidae: Nannostomus) reveals cryptic diversity across the Brazilian Amazon.

Nannostomus is comprised of 20 species. Popularly known as pencilfishes the vast majority of these species lives in the flooded forests of the Amazon basin and are popular in the ornamental trade. Among the lebiasinids, it is the only genus to have undergone more than one taxonomic revision. Even so, it still possesses poorly defined species. Here, we report the results of an application of DNA barcoding to the identification of pencilfishes and highlight the deeply divergent clades within four nominal species. We surveyed the sequence variation in the mtDNA cytochrome c oxidase subunit I gene among 110 individuals representing 14 nominal species that were collected from several rivers along the Amazon basin. The mean Kimura-2-parameter distances within species and genus were 2% and 19,0%, respectively. The deep lineage divergences detected in N. digrammus, N. trifasciatus, N. unifasciatus and N. eques suggest the existence of hidden diversity in Nannostomus species. For N. digrammus and N. trifasciatus, in particular, the estimated divergences in some lineages were so high that doubt about their conspecific status is raised.

Cytotaxonomy and karyoevolution of the genus Crenicichla (Perciformes, Cichlidae)

Karyotypes of six cichlid species of the genus Crenicichla were investigated. The species C. cincta, C. inpa, C. reticulata, C. lugubris, and C. cf. johanna were collected from Amazon basin, and C. britskii was collected from the Paraná-Paraguai basin. All of the analysed species showed 2n = 48 chromosomes; however, C. cincta, C. lugubris, C. cf. johanna, and C. britskii had a karyotype formula of 8M-SM+40ST-A, FN = 56, while C. inpa and C. reticulata exhibited the formula 6M-SM+42ST-A, FN = 54. Analysis of active Ag-NORs revealed two NOR-bearing chromosomes in all species; however, theses cistrons were located on different chromosome pairs and/or in different chromosome locations in each species. This condition bears evolutionary significance, since it is the main chromosome marker of the process of karyotypic evolution among the species of the genus Crenicichla. In general, C-banding revealed a similar constitutive heterochromatin pattern in all species, although it was possible to detect some features that led us to infer that Crenicichla also presents a species-specific heterochromatin pattern.