In silico analysis of genomic variables associated to HPV16 integration sites / Análisis in silico de variables genómicas asociadas a sitios de integración de HPV16

Background: Despite current prophylactic interventions, a significant proportion of patients suffers a cancer-specific mortality, leading to a global awareness of the importance of identifying factors associated to the etiology of HPV-associated cancer. According to this, HPV-DNA integration into human genome is an important event in the pathogenesis. Purpose: To identify in silico, molecular regions of the genome where the HPV integration events occur Methods: We performed a bioinformatic study based on a systematic search in Medline through PubMed, Embase and Lilacs from inception to April 2019. We used the UCSC Genome Browser Home (https://genome.ucsc.edu) to evaluate the genetic environment. Results: HPV integration sites by anatomical location related to cervical cancer were 374 (61%). In addition, 325 (87%) of these integration sites had HPV-16, 21 (5%) had HPV-18 and 28 (7%) had another type of genotype. Oro-pharyngeal cavity was the second anatomic site with 162 (26%) integration sites. It is noteworthy that the HPV-16 was found integrated into 160 (99%) analyzed sites. Conclusion: Our results suggest that many of the integration sites reported in the scientific literature are HPV 16 from squamous cell carcinomas and 50% of HPV16 were integrated into transcriptional units that might affect the expression of gene target.

Antecedentes: A pesar de las intervenciones profilácticas actuales, una proporción significativa de pacientes muere debido al cáncer, lo que aumenta la conciencia global de la importancia de identificar los factores asociados a la etiología del cáncer asociado al VPH. Según esto, la integración del ADN-VPH en el genoma humano es un evento importante en la patogénesis. Propósito: Identificar in silico, las regiones moleculares del genoma donde ocurren los eventos de integración del VPH Métodos: Realizamos un estudio bioinformático basado en una búsqueda sistemática en Medline a través de PubMed, Embase y Lilacs desde el inicio hasta abril de 2019. Utilizamos el UCSC Genome Browser Home (https://genome.ucsc.edu) para evaluar el entorno genético. Resultados: Los sitios de integración del VPH relacionados con el cáncer de cuello uterino fueron 374 (61%). Además, 325 (87%) de estos sitios de integración tenían VPH-16, 21 (5%) tenían VPH-18 y 28 (7%) tenían otro tipo de genotipo. La cavidad orofaríngea fue el segundo sitio anatómico con 162 (26%) sitios de integración. Es de destacar que el VPH-16 se encontró integrado en 160 (99%) sitios analizados. Conclusión: Nuestros resultados sugieren que muchos de los sitios de integración reportados en la literatura científica que presentan al VPH-16 son carcinomas de células escamosas y que el 50% de estos VPH-16 se integraron en unidades transcripcionales que podrían afectar la expresión de algún gen objetivo.

Genomic variations in the counterpart normal controls of lung squamous cell carcinomas / 医学前沿

Lung squamous cell carcinoma (LUSC) causes approximately 400 000 deaths each year worldwide. The occurrence of LUSC is attributed to exposure to cigarette smoke, which induces the development of numerous genomic abnormalities. However, few studies have investigated the genomic variations that occur only in normal tissues that have been similarly exposed to tobacco smoke as tumor tissues. In this study, we sequenced the whole genomes of three normal lung tissue samples and their paired adjacent squamous cell carcinomas.We then called genomic variations specific to the normal lung tissues through filtering the genomic sequence of the normal lung tissues against that of the paired tumors, the reference human genome, the dbSNP138 common germline variants, and the variations derived from sequencing artifacts. To expand these observations, the whole exome sequences of 478 counterpart normal controls (CNCs) and paired LUSCs of The Cancer Genome Atlas (TCGA) dataset were analyzed. Sixteen genomic variations were called in the three normal lung tissues. These variations were confirmed by Sanger capillary sequencing. A mean of 0.5661 exonic variations/Mb and 7.7887 altered genes per sample were identified in the CNC genome sequences of TCGA. In these CNCs, C:G→T:A transitions, which are the genomic signatures of tobacco carcinogen N-methyl-N-nitro-N-nitrosoguanidine, were the predominant nucleotide changes. Twenty five genes in CNCs had a variation rate that exceeded 2%, including ARSD (18.62%), MUC4 (8.79%), and RBMX (7.11%). CNC variations in CTAGE5 and USP17L7 were associated with the poor prognosis of patients with LUSC. Our results uncovered previously unreported genomic variations in CNCs, rather than LUSCs, that may be involved in the development of LUSC.

Allopatric chromosomal variation in Nematocharax venustus Weitzman, Menezes & Britski, 1986 (Actinopterygii: Characiformes) based on mapping of repetitive sequences

Characiformes is the most cytogenetically studied group of freshwater Actinopterygii, but karyotypical data of several taxa remain unknown. This is the case of Nematocharax , regarded as a monotypic genus and characterized by marked sexual dimorphism. Therefore, we provide the first cytogenetic report of allopatric populations of Nematocharax venustus based on distinct methods of chromosomal banding and fluorescence in situ hybridization (FISH) with repetitive DNA probes (18S and 5S rDNA). The karyotype macrostructure was conserved in all specimens and populations, independently on sex, since they shared a diploid number (2n) of 50 chromosomes divided into 8m+26sm+14st+2a. The heterochromatin was mainly distributed at pericentromeric regions and base-specific fluorochrome staining revealed a single pair bearing GC-rich sites, coincident with nucleolar organizer regions (NORs). On the other hand, interpopulation variation in both number and position of repetitive sequences was observed, particularly in relation to 5S rDNA. Apparently, the short life cycles and restricted dispersal of small characins, such as N. venustus , might have favored the divergence of repetitive DNA among populations, indicating that this species might encompass populations with distinct evolutionary histories, which has important implications for conservation measures.

Characiformes é o grupo de Actinopterygii de água doce mais estudado citogeneticamente, porém dados cariotípicos de vários taxa permanecem desconhecidos. Este é o caso de Nematocharax , considerado um gênero monotípico e caracterizado pelo acentuado dimorfismo sexual. Em vista disso, nós fornecemos a primeira descrição citogenética de populações alopátricas de Nematocharax venustus , baseada em métodos distintos de bandamento cromossômico e hibridação fluorescente in situ (FISH) com sondas de DNA repetitivo (DNAr 18S e 5S). A macroestrutura cariotípica mostrou-se conservada em todos os espécimes e populações, independentemente do sexo, uma vez que compartilharam um número diploide (2n) de 50 cromossomos dividido em 8m+26sm+14st+2a. A heterocromatina distribuiu-se principalmente nas regiões pericentroméricas e a coloração com fluorocromos base-específicos revelou um único par portador de sítios GC-ricos, coincidentes com as regiões organizadoras de nucléolo (RONs). Por outro lado, foi observada uma variação interpopulacional no número e na posição das sequências repetitivas, especialmente em relação ao DNAr 5S. Aparentemente, ciclos de vida curtos e dispersão restrita dos pequenos caracídeos, tal como N. venustus , podem ter favorecido a divergência do DNA repetitivo entre as populações, indicando que essa espécie pode englobar populações com distintas histórias evolutivas, o que tem implicações importantes para medidas de conservação.

Estudo funcional da região não estruturada de ligação entre os domínios BRCT em tandem da proteína BRCA1 / [Estudo funcional da região não estruturada de ligação entre os domínios BRCT em tandem da proteína BRCA1]

As vias de reparo ao dano de DNA (RDD) são essenciais para a manutenção da integridade genômica. Mutações em genes que atuam nessas vias podem contribuir para o desenvolvimento de câncer. BRCA1 é um gene extremamente polimórfico, codificando uma proteína envolvida em importantes eventos de sinalização nuclear em resposta ao dano de DNA. Portadores de mutações em BRCA1 que levam a uma proteína disfuncional podem ter o risco aumentado de desenvolvimento de câncer de mama e ovário em até 80%. Alterações em BRCA1, tais como inserções, deleções e mutações nonsense, podem ser inferidas como patogênicas, uma vez que a perda dos últimos 11 resíduos de aminoácidos na região C-terminal resulta em uma proteína não funcional. Mutações do tipo missense, assim como inserções e deleções que mantém o quadro de leitura, apresentam dificuldades na classificação. Estudos funcionais representam uma importante ferramenta para a classificação da patogenicidade dos variantes com baixa frequência na população (ou ainda não identificados). Em 2007, nosso grupo estabeleceu um ensaio funcional que correlaciona a atividade transcricional de BRCA1 e a integridade da região C-terminal da proteína (ensaio de TA) ­ essa região (aminoácidos 1396 a 1863) é capaz de recrutar a holoenzima RNA polimerase II. Assim, é possível correlacionar a atividade de um sistema repórter com a patogenicidade de uma mutação específica. Este estudo tem foco na região de ligação entre os domínios tBRCT, denominada linker (aminoácidos 1737 a 1759). Foram preditas todas as mutações naturais missense no linker (132 variantes) e, utilizando estratégias de bioinformática (Align-GVGD, SFIT e PolyPhen), foram estabelecidas os níveis de associação ao câncer. Variantes previamente estudados/classificados em outros trabalhos (16) não foram incluídos, resultando em um conjunto de 116 variantes. Somente 23 variantes foram preditos como associados ao câncer por todos algoritmos. Os variantes selecionados para o estudo foram gerados e clonados no vetor pCDNA3, codificando uma proteína de fusão (domínio de ligação ao DNA de GAL4 fusionado a BRCA1 C-terminal). As construções foram utilizadas para obtenção de dados funcionais através do ensaio de TA. Os experimentos foram originalmente conduzidos a 37oC. A maioria dos variantes (20) apresentou um perfil patogênico, enquanto 3 varinate, todos na posição 1740, apresentaram perfil semelhante aos controles não patogênicos. Esses variantes demonstraram uma variação significativa na atividade transcricional (tanto entre replicatas, quanto experimentos independentes), sugerindo um comportamento termossensível. Assim, todos os variantes foram testados a 30ºC. Os variantes na posição V1740 mantiveram um comportamento não patogênico, no entanto 9 variantes apresentaram aumento estatisticamente significativo na atividade transcricional. Não foram observadas alterações significativas na estrutura secundária do linker como consequência de substituições de aminoácidos quando analisados através do diagrama de Ramachandran. As diferenças observadas a 37ºC e 30ºC sugerem que o linker é, possivelmente, um segmento termossensível na estrutura de BRCA1. Todos os dados gerados serão avaliados em modelo matemático (VarCall) para determinar a patogenicidade dos variantes de BRCA1 abordados nesse estudo.

Snakebites as a largely neglected problem in the Brazilian Amazon: highlights of the epidemiological trends in the State of Amazonas

Envenoming snakebites are thought to be a particularly important threat to public health worldwide, especially in rural areas of tropical and subtropical countries. The true magnitude of the public health threat posed by snakebites is unknown, making it difficult for public health officials to optimize prevention and treatment. The objective of this work was to conduct a systematic review of the literature to gather data on snakebite epidemiology in the Amazon region and describe a case series of snakebites from epidemiological surveillance in the State of Amazonas (1974-2012). Only 11 articles regarding snakebites were found. In the State of Amazonas, information regarding incidents involving snakes is scarce. Historical trends show an increasing number of cases after the second half of the 1980s. Snakebites predominated among adults (20-39 years old; 38%), in the male gender (78.9%) and in those living in rural areas (85.6%). The predominant snake envenomation type was bothropic. The incidence reported by the epidemiological surveillance in the State of Amazonas, reaching up to 200 cases/100,000 inhabitants in some areas, is among the highest annual snakebite incidence rates of any region in the world. The majority of the cases were reported in the rainy season with a case-fatality rate of 0.6%. Snakebite envenomation is a great disease burden in the State of Amazonas, representing a challenge for future investigations, including approaches to estimating incidence under-notification and case-fatality rates as well as the factors related to severity and disabilities.

Estudo de variações genômicas para a identificação de biomarcadores personalizados e novos alvos terapêuticos em tumores colorretais / Study of genomic variation to identify biomarkers and novel therapeutic targets in colorectal tumors

O câncer colorretal é um dos tipos de tumores mais frequentes no mundo. A atual dificuldade na avaliação correta da resposta ao tratamento torna necessário o desenvolvimento de novas abordagens de detecção tumoral. Atualmente, o sequenciamento genômico em larga escala permite um estudo mais compreensivo das alterações estruturais e de sequência presentes no tumor. A aplicação destas abordagens de maneira personalizada permite o desenvolvimento de biomarcadores tumor específicos que podem facilitar a avaliação de resposta ao tratamento e a presença de doença residual, bem como revelar alterações de sequência em genes capazes de servir de novos alvos terapêuticos. Neste estudo foi desenvolvida uma metodologia eficiente para a identificação de biomarcadores baseados na existência de variações estruturais em genomas de tumores de reto, eliminando a necessidade de sequenciamento do genoma normal do mesmo paciente e diminuindo portanto o custo da abordagem. Os biomarcadores encontrados para cada um dos seis pacientes foram utilizados para avaliar a presença de doença residual após o tratamento através da detecção de DNA tumoral circulante nas amostras de plasma coletadas em momentos diferentes do tratamento. O sequenciamento em baixa cobertura personalizado é portanto uma alternativa viável e promissora para avaliar a resposta ao tratamento em pacientes com tumores de reto. Na segunda parte do estudo, a análise de linhagens celulares de tumores colorretais revelou uma grande quantidade de mutações pontuais somáticas (SNVs e InDels) em genes codificadores para proteínas de superfície celular (surfaceoma). Estas alterações no surfaceoma indicam potenciais novos alvos para drogas e vias regulatórias alteradas neste tipo de tumor. Além disso, estas mutações pontuais também são responsáveis pela geração de epítopos com potencial imunogênico e estes novos epítopos podem ser aplicados como vacinas antitumorais personalizadas e já haviam sido propostos como uma alternativa terapêutica. A presença de novos epítopos, principalmente nas linhagens com elevadas taxas de mutação (resultante da instabilidade de microssatélites e mutações em genes de reparo de DNA tipo mismatch ou POLE), sugerem também um potencial uso de drogas moduladoras do sistema imune em pacientes com tumores que apresentam estas mesmas características. Portanto, o estudo de alterações genômicas em tumores primários e linhagens de câncer colorretal permitiu a detecção de variações estruturais que foram utilizadas como biomarcadores personalizados em pacientes com tumores de reto assim como a identificação de genes contendo mutações pontuais em linhagens celulares de câncer colorretal, que revelam potenciais novos alvos terapêuticos a serem explorados na clínica

Colorectal cancer is one of the more frequent tumor types in the world. To select the appropriate treatment course, it is necessary to develop more precise diagnostic approaches. The current availability of high throughput genome sequencing methods allows for a comprehensive characterization of the structural and sequence alterations present in each tumor. The use of tumor genome sequencing in a personalized setting can result in tumor specific biomarkers that help evaluate response to treatment and the presence of residual disease, improving the clinical management of these patients, and also reveal sequence alterations in genes capable of serving as new therapeutic targets. In this study we developed an efficient bioinformatics pipeline to identify biomarkers based on the existing structural alterations in rectal tumor genomes, eliminating the need to sequence the matched normal genome and therefore reducing the cost for this approach. The biomarkers found for each of the six patients were used to evaluate the presence of residual disease after treatment through the detection of circulating tumor DNA in plasma samples collected at different points during the treatment. Sequencing tumor genomes with low coverage is therefore a viable and promising alternative to follow up rectal cancer patient's response to treatment. In the second part of this study, the analysis of colorectal cancer cell lines revealed a large quantity of point mutations (SNVs and InDels) in genes coding for proteins located in the cell surface (surfaceome). These alterations in the surfaceome indicate potential new drug targets and altered pathways in this type of tumor. Furthermore, these point mutations are also responsible for the generation of new epitopes with immunogenic potential and these new epitopes can be applied as personalized tumor vaccines and had previously been proposed as a therapeutic alternative. The presence of new epitopes, especially in the cell lines with elevated mutation rates (resulting from MSI and mutations in DNA mismatch-repair genes or POLE), suggests a potential use of immune checkpoint target drugs in patients with tumors that share these genetic characteristics. With a large-scale bioinformatics approach, we detected new tumor epitopes resulting from point mutations, present in most of the cell lines used. The analysis of gene expression data puts into perspective both the somatic mutations found and which targets are promising as well as the development of therapies based on vaccines derived from tumor epitopes. In conclusion, the study of genomic alterations in primary tumors and colorectal cancer cell lines allowed the detection of structural variations that were used as personalized biomarkers in patients with rectal tumors as well as the identification of genes containing point mutations in colorectal cancer cell lines, that reveal potential new therapeutic targets to be explored in the clinical setting

A retrotransposição de mRNAs como fator de variabilidade genética no genoma humano e de outros primatas / The retrotransposition of mRNAs as a factor of genetic variability in the human and other primates genomes

Duplicação genica é uma das principais forças levando a evolução dos genomas eucarioto. O impacto de duplicações gênicas/genômicas vem sendo investigado a muito tempo em humanos e outros primatas. Um segundo mecanismo de duplicação gênica, a retrotransposição baseada em RNA maduros, vem sendo menos estudada devido ao seu potencial menor de gerar cópias funcionais. No entanto, recentemente, publicações descreveram retrocópias funcionais em humanos, roedores e mosca de fruta. Nesta tese, para investigar sobre retrocópias causando variabilidade genética no genoma de primatas, nós desenvolvemos a implementamos os métodos para detectar estas inserções. Utilizando nove genomas e transcriptomas publicamente disponíveis (sete primatas e dois roedores) nós confirmamos um número similar, porém, com origem independente, de retrocópias em primatas e roedores. Nós também encontramos um enriquecimento de retrocópias no genoma de Platyrrhini, possivelmente explicado pela expansão de L1PA7 e L1P3 nestes genomas. Posteriormente, nós analisamos a ortologia de retrocópias no genoma de primatas e encontramos 127 eventos específicos à linhagem humana. Nós também exploramos dados do projeto 1000 Genomes para detectar retrocópias polimórficas (retroCNVs germinativos) e encontramos 17 eventos, presentes no genoma referência humano, mas ausentes em mais de um indivíduo. Similarmente, nós investigamos novas retroduplicações de mRNAs no genoma humano, detectando 21 eventos ausentes do genoma referência. Finalmente, investigamos a existência de retroCNVs somáticos e descrevemos sete possíveis retrocópias somáticas. Apesar de sua possível insignificância, nós encontramos que algumas retrocópias compartilhadas entre todos os primatas, espécie específicas, e polimórficas podem ser expressas per se ou como transcritos quiméricos com genes hospedeiros. Sobretudo, nós encontramos que retrocópias são um fator importante da variabilidade genética inter-espécie, intra-espécie e intra-indivíduo e podem estar influenciando a evolução de mamíferos ao criar reservatórios de duplicações potencialmente funcionais

Gene duplication is a major driving force of evolution in eukaryotic genome. The impact of gene/genomic duplication has long been investigated in human and other primates. A second mechanism of gene duplication, retrotransposition, which is based on mature RNA, has been traditionally less studied due to their lower potential to generate functional copies. Recently, however, publications described functional retrocopies in humans, murines and drosophila. Here, to gain insights of the genetic variability arising from retrocopies on primate genomes, we developed and implemented the methods to detect these insertions. Using nine publicly available reference genomes and transcriptomes (seven primates and two rodents) we described a similar number independently arisen retrocopies in primates and rodents. We also found an enrichment of retrocopies in Platyrhinni genomes, putatively explained by the expansion of L1PA7 and L1P3 in these genomes. Next, we evaluated the orthology of retrocopies in primate genomes and found 127 events specific to human lineage. We also explored 1000 Genomes Project data to detect polymorphic events (germinative retroCNVs) on human populations and found 17 events, present on the reference genome, absent in more than one individual. Conversely, we also investigated new insertions of mRNA retroduplications in the human genome, detecting 21 events absent to the human reference genome. Finally, we evaluated the existence of somatic retroCNVs and described seven putative somatic retrocopies. Despite their putative insignificance, we found that some of these shared, specie-specific and polymorphic events may be expressed per se and as chimeric transcripts within host genes. Taken together, we found that retrocopies are a great factor of genetic variation interspecie, intraspecie e intraindividual and may be affecting mammal evolution by creating reservoirs of potentially functional duplications

Genomic characterization of some Iranian children with idiopathic mental retardation using array comparative genomic hybridization.

BACKGROUND: Mental retardation (MR) has a prevalence of 1‑3% and genetic causes are present in more than 50% of patients. Chromosomal abnormalities are one of the most common genetic causes of MR and are responsible for 4‑28% of mental retardation. However, the smallest loss or gain of material visible by standard cytogenetic is about 4 Mb and for smaller abnormalities, molecular cytogenetic techniques such as array comparative genomic hybridization (array CGH) should be used. It has been shown that 15‑25% of idiopathic MR (IMR) has submicroscopic rearrangements detectable by array CGH. In this project, the genomic abnormalities were investigated in 32 MR patients using this technique. MATERIALS AND METHODS: Patients with IMR with dysmorphism were investigated in this study. Karyotype analysis, fragile X and metabolic tests were first carried out on the patients. The copy number variation was then assessed in a total of 32 patients with normal results for the mentioned tests using whole genome oligo array CGH. Multiple ligation probe amplification was carried out as a confirmation test. RESULTS: In total, 19% of the patients showed genomic abnormalities. This is reduced to 12.5% once the two patients with abnormal karyotypes (upon re‑evaluation) are removed. CONCLUSION: The array CGH technique increased the detection rate of genomic imbalances in our patients by 12.5%. It is an accurate and reliable method for the determination of genomic imbalances in patients with IMR and dysmorphism.

AnsNGS: An Annotation System to Sequence Variations of Next Generation Sequencing Data for Disease-Related Phenotypes / 대한의료정보학회지

OBJECTIVES: Next-generation sequencing (NGS) data in the identification of disease-causing genes provides a promising opportunity in the diagnosis of disease. Beyond the previous efforts for NGS data alignment, variant detection, and visualization, developing a comprehensive annotation system supported by multiple layers of disease phenotype-related databases is essential for deciphering the human genome. To satisfy the impending need to decipher the human genome, it is essential to develop a comprehensive annotation system supported by multiple layers of disease phenotype-related databases. METHODS: AnsNGS (Annotation system of sequence variations for next-generation sequencing data) is a tool for contextualizing variants related to diseases and examining their functional consequences. The AnsNGS integrates a variety of annotation databases to attain multiple levels of annotation. RESULTS: The AnsNGS assigns biological functions to variants, and provides gene (or disease)-centric queries for finding disease-causing variants. The AnsNGS also connects those genes harbouring variants and the corresponding expression probes for downstream analysis using expression microarrays. Here, we demonstrate its ability to identify disease-related variants in the human genome. CONCLUSIONS: The AnsNGS can give a key insight into which of these variants is already known to be involved in a disease-related phenotype or located in or near a known regulatory site. The AnsNGS is available free of charge to academic users and can be obtained from http://snubi.org/software/AnsNGS/.

Genetic population structure of Hawksbill turtle [Eretmochelys imbricta] using microsatellite analysis

Information on the genetic structure of marine species is essential for stock improvement programs. In order to analyses the genetic diversity of the Hawksbill turtle [Eretmochelys imbricte] by the microsatellite genetic method, 64 samples were caught from the beaches located in Kish and Qeshm islands. Polymerase chain reactions [PCR] of genomic DNA extracted from the samples were carried out using 5 pairs of microsatellite primers. The results of this study indicated that all 5 pairs of primers were polymorphic. Average numbers of real allele and effective allele were 4.90 and 2.99, respectively. Average rate of observed heterozygosity was 0.570 and that for expected heterozygosity was 0.616. Study of the Hardy-Weinberg equilibrium was shown the entire locus had not equilibrium except Cm3 and Ei8 locus in Kish area. Fst [0.166] and Rst [0.634] calculated by the Analysis of Molecular Variance [AMOVA] test illustrated that there are separate populations of Hawksbill turtle in this part of the Persian Gulf [Kish and Qeshm islands]. It seems that Kish's turtles live under better conditions in contrast to their Qeshm counterparts. Diminution of genetic variation within examined population decreases its adaptation to environmental alterations. We identified two different E. imbricte populations from north of the Persian Gulf

Clinical Applications of Chromosomal Microarray Analysis

Chromosomal microarray analysis (CMA) enables the genome-wide detection of submicroscopic chromosomal imbalances with greater precision and accuracy. In most other countries, CMA is now a commonly used clinical diagnostic test, replacing conventional cytogenetics or targeted detection such as FISH or PCR-based methods. Recently, some consensus statements have proposed utilization of CMA as a first-line test in patients with multiple congenital anomalies not specific to a well-delineated genetic syndrome, developmental delay/intellectual disability, or autism spectrum disorders. CMA can be used as an adjunct to conventional cytogenetics to identify chromosomal abnormalities observed in G-banding analysis in constitutional or acquired cases, leading to a more accurate and comprehensive assessment of chromosomal aberrations. Although CMA has distinct advantages, there are several limitations, including its inability to detect balanced chromosomal rearrangements and low-level mosaicism, its interpretation of copy number variants of uncertain clinical significance, and significantly higher costs. For these reasons, CMA is not currently a replacement for conventional cytogenetics in prenatal diagnosis. In clinical applications of CMA, knowledge and experience based on genetics and cytogenetics are required for data analysis and interpretation, and appropriate follow-up with genetic counseling is recommended.