Cherubism in Saudi population: a rare case report / Querubismo na população Saudi: relato de um caso raro

Cherubism is a rare hereditary benign fibro-osseous disorder characterised by bilateral swelling of the mandible and/or maxilla with varying severity of involvement. It occurs because of dominant mutations in SH3BP2 gene on the chromosome 4p16.3. On radiography cherubic lesions appear as multilocular cystic radiolucencies in the jaw bones giving a soap bubble appearance. These lesions usually heal by themselves by the time the patient attains puberty. Treatment is necessary only in aggressive cases where there is severe facial deformity or vital functions are hampered. Surgical corrections are preferred when the lesion is in its dormant phase. The aim of the present case report is to illustrate a case of cherubism in a 9-year-old Saudi boy which is a very rare occurrence as only 1 case of cherubism has been reported so far in the Saudi Arabian population (AU)

Querubismo é uma desordem fibro-óssea hereditária rara caracterizada por aumento de volume bilateral da mandíbula e/ou maxila com graus variáveis de severidade. Ocorre devido a mutação dominante no gene SH3BP2 no cromossomo 4p16.3. Radiograficamente as lesões de querubismo aparecem como radiolucência multilocular semelhantes a bolhas de sabão nos ossos maxilares. Geralmente as lesões involuem espontaneamente quando o paciente atinge a puberdade. O tratamento se faz necessário apenas nos casos mais agressivos que demonstram deformidade facial severa ou comprometimento de funções vitais. Correções cirúrgicas são preferíveis quando a lesão está na fase dormente. O objetivo do presente relato é ilustrar um caso de querubismo em um paciente de 9 anos da Arábia Saudita, sendo este um evento raríssimo com apenas um outro caso relatado na população da Arábia Saudita (AU)

Alterações sistêmicas na assinatura do ciclo celular de pacientes com COVID-19 / Systemic changes in the cell cycle signature of patients with COVID-19

Com base nas perturbações fosfoproteômicas de moléculas associadas ao ciclo celular em células infectadas pelo coronavírus causador da síndrome respiratória aguda grave (SARSCoV)-2, a hipótese de inibidores do ciclo celular como uma terapia potencial para a doença de coronavírus 2019 (COVID-19) foi proposta. No entanto, o cenário das alterações do ciclo celular em COVID-19 permanece inexplorado. Aqui, realizamos uma análise integrativa de sistemas imunológicos de proteoma publicamente disponível (espectrometria de massa) e dados de transcriptoma (sequenciamento de RNA em massa e de célula única [scRNAseq]), com o objetivo de caracterizar mudanças globais na assinatura do ciclo celular de pacientes com COVID-19. Além de módulos de co-expressão de genes significativos enriquecidos associados ao ciclo celular, encontramos uma rede interconectada de proteínas diferencialmente expressas associadas ao ciclo celular (DEPs) e genes (DEGs) integrando dados moleculares de 1.480 indivíduos (974 pacientes infectados por SARS-CoV-2 e 506 controles [controles saudáveis ou indivíduos com outras doenças respiratórias]). Entre esses DEPs e DEGs estão várias ciclinas (CCNs), ciclo de divisão celular (CDCs), quinases dependentes de ciclinas (CDKs) e proteínas de manutenção de minicromossomos (MCMs). Embora os pacientes com COVID-19 compartilhem parcialmente o padrão de expressão de algumas moléculas associadas ao ciclo celular com outras doenças respiratórias, eles exibiram uma expressão significativamente maior de moléculas associadas ao ciclo celular relacionadas à gravidade da doença. Notavelmente, a assinatura do ciclo celular predominou nos leucócitos do sangue dos pacientes, mas não nas vias aéreas superiores. Os dados de scRNAseq de 229 indivíduos (159 pacientes com COVID- 19 e 70 controles) revelaram que as alterações das assinaturas do ciclo celular predominam nas células B, T e NK. Esses resultados fornecem uma compreensão global única das alterações nas moléculas associadas ao ciclo celular em pacientes com COVID-19, sugerindo novas vias putativas para intervenção terapêutica

Based on phosphoproteomics perturbations of cell cycle-associated molecules in severe acute respiratory syndrome coronavirus (SARS-CoV)-2-infected cells, the hypothesis of cell cycle inhibitors as a potential therapy for Coronavirus disease 2019 (COVID-19) has been proposed. However, the landscape of cell cycle alterations in COVID-19 remains mostly unexplored. Here, we performed an integrative systems immunology analysis of publicly available proteome (mass spectrometry) and transcriptome data (bulk and single-cell RNA sequencing [scRNAseq]), aiming to characterize global changes in the cell cycle signature of COVID-19 patients. Beyond significant enriched cell cycle-associated gene co-expression modules, we found an interconnected network of cell cycle-associated differentially expressed proteins (DEPs) and genes (DEGs) by integrating molecular data of 1,480 individuals (974 SARS-CoV- 2 infected patients and 506 controls [either healthy controls or individuals with other respiratory illness]). Among these DEPs and DEGs are several cyclins (CCNs), cell division cycle (CDCs), cyclin-dependent kinases (CDKs), and mini-chromosome maintenance proteins (MCMs). Although COVID-19 patients partially shared the expression pattern of some cell cycleassociated molecules with other respiratory illnesses, they exhibited a significantly higher expression of cell cycle-associated molecules associated with disease severity. Notably, the cell cycle signature predominated in the patients blood leukocytes but not in the upper airways. The scRNAseq data from 229 individuals (159 COVID-19 patients and 70 controls) revealed that the alterations of cell cycle signatures predominate in B, T, and NK cells. These results provide a unique global comprehension of the alterations in cell cycle-associated molecules in COVID-19 patients, suggesting new putative pathways for therapeutic intervention

Chromosomal integration of large DNA fragments in microorganisms: a review / 生物工程学报

The modern bio-fermentation industry requires design and creation of efficient microbial cell factories for directed conversion of raw materials to target products. The main criteria for assessing the performance of microbial cell factories are their product synthesis capacity and stability. Due to the deficiencies of plasmids in gene expression such as instability and being easy to lose, integration of genes into chromosome is often a better choice for stable expression in microbial hosts. To this end, chromosomal gene integration technology has received much attention and has developed rapidly. In this review, we summarize the recent research progresses of chromosomal integration of large DNA fragments in microorganisms, illustrate the principles and features of various technologies, highlight the opportunity brought by the CRISPR-associated transposon systems, and prospect future research direction of this technology.

The value of chromosomal microarray analysis and fluorescence in situ hybridization for the prenatal diagnosis of chromosomal mosaicisms / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) for the prenatal diagnosis of chromosomal mosaicisms.@*METHODS@#A total of 775 pregnant women who had visited the Prenatal Diagnosis Center of Yancheng Maternal and Child Health Care Hospital from January 2018 to December 2020 were selected as study subjects. Chromosome karyotyping analysis and CMA were carried out for all women, and FISH was used to validate the suspected mosaicism cases.@*RESULTS@#Among the 775 amniotic fluid samples, karyotyping has identified 13 mosaicism cases, which yielded a detection rate of 1.55%. Respectively, there were 4, 3, 4 and 2 cases for sex chromosome number mosaicisms, abnormal sex chromosome structure mosaicisms, abnormal autosomal number mosaicisms and abnormal autosomal structure mosaicisms. CMA has only detected only 6 of the 13 cases. Among 3 cases verified by FISH, 2 cases were consistent with the karyotyping and CMA results, and clearly showed low proportion mosaicism, and 1 case was consistent with the result of karyotyping but with a normal result by CMA. Eight pregnant women had chosen to terminate the pregnancy (5 with sex chromosome mosaicisms and 3 with autosomal mosaicisms).@*CONCLUSION@#For fetuses suspected for chromosomal mosaicisms, CMA, FISH and G-banding karyotyping should be combined to determine the type and proportion of mosaicisms more precisely in order to provide more information for genetic counseling.

Follow-up of fetuses with de novo copy number variations of unknown significance detected by chromosomal microarray analysis / 中华医学遗传学杂志

OBJECTIVE@#To analyze the prognosis of fetuses identified with de novo variants of unknown significance (VOUS) by chromosome microarray analysis (CMA).@*METHODS@#A total of 6 826 fetuses who underwent prenatal CMA detection at the Prenatal Diagnosis Center of Drum Tower Hospital from July 2017 to December 2021 were selected as the study subjects. The results of prenatal diagnosis, and outcome of fetuses identified with VOUS of de novo origin were followed up.@*RESULTS@#Among the 6 826 fetuses, 506 have carried VOUS, of which 237 were detected for the parent-of-origin and 24 were found to be de novo. Among the latters, 20 were followed up for 4 to 24 months. Four couples had opted elective abortion, 4 had developed clinical phenotypes after birth, and 12 were normal.@*CONCLUSION@#Fetuses with VOUS should be continuously follow-up, in particular those carrying de novo VOUS, in order to clarify their clinical significance.

9p21 Locus Polymorphisms: Risk and Severity Factors of Coronary Artery Disease in Venezuelan Patients

Abstract Background: The 9p21 region is the most relevant locus associated with coronary heart disease in different populations. However, there are no studies that prove that this region is a risk factor in the Venezuelan population. Objectives: To analyze whether or not the 9p21 rs1333049 polymorphism is a risk factor for acute myocardial infarction (AMI) in Venezuelan patients, as well as to investigate its correlation with cardiovascular risk factors (CVRF), age of occurrence, type and severity of infarction, and the correlation of the rs10757274 polymorphism with severity of coronary artery disease. Methods: This was an association study, including 487 unrelated Venezuelan individuals, grouped in 354 patients with AMI and 133 controls. The rs1333049 and rs10757274 polymorphisms were determined using the polymerase chain reaction (PCR) technique with sequence-specific primers. The analysis of association was determined using the SNPStats tool. The continuous variable description and the correlations were performed using the SPSS statistical software. Significance was established at p<0.05. Results: A positive correlation was observed between the rs1333049 polymorphism and the presence of hypertension ( r: 0.145, p: 0.006), and between hypertension and heart infarction ( r: 0.318, p: <0.0001). A positive correlation was found between the rs10757274 polymorphism and the number of coronary vessels that presented obstructive lesions in patients aged ≤ 55 years ( r: 0.276, p: 0.0078). Conclusion: The rs1333049 polymorphism at the 9p21 locus is correlated with hypertension in Venezuelan patients, while the rs10757274 polymorphism is associated with the progression of coronary atherosclerosis, suggested by the correlation with the number of coronary vessels that presented significant obstructive lesions.

Síndrome de insensibilidad completa a andrógenos / Complete androgen insensitivity syndrome

El síndrome de insensibilidad a los andrógenos (SIA), conocido también como un síndrome de feminización testicular, incluye un grupo variado de mutaciones que se relacionan con la disfunción de los receptores de andrógenos y la resistencia de los tejidos diana a la acción de las hormonas masculinas. Es causado por alteraciones genéticas localizadas en la secuencia de codificación de los receptores de andrógenos ligada al cromosoma Xq11 - 12, el gen que codifica al receptor de los andrógenos, de un individuo genéticamente masculino (46 XY). Las formas clínicas moderada, parcial o completa, dependen del grado de insensibilidad androgénica. Los avances en las causas genéticas han permitido que estas condiciones congénitas de desarrollo del sexo cromosómico, gonadal o anatómico atípico sean denominados trastornos de diferenciación sexual

Androgen insensitivity syndrome (AIS), also known as testicular feminization syndrome, includes a diverse group of mutations that are related to androgen receptor dysfunction and resistance of target tissues to the action of hormones masculine. It is caused by localized genetic alterations in the androgen receptor coding sequence linked to chromosome Xq11-12, the gene encoding the androgen receptor, of a genetically male (46 XY) individual. Moderate, partial, or complete clinical forms depend on the degree of androgen insensitivity. Advances in genetic causes have allowed these congenital conditions of atypical chromosomal, gonadal, or anatomical sex development to be called disorders of sexual differentiation

Tracking the evolutionary pathways among Brazilian Lebiasina species (Teleostei: Lebiasinidae): a chromosomal and genomic comparative investigation

Despite several difficulties in chromosomal analyses of small-sized fishes, the cytogenetics of the Lebiasinidae was largely improved in the last years, showing differential patterns in the chromosomal evolution inside the family. In this context, it has been shown that genus Lebiasina preserves its karyotypic macrostructure, composed of 2n = 36 chromosomes, whereas the other genera generally present higher 2n. This study focused on the comparative cytogenetics of three Lebiasina species, one of them analyzed here for the first time, using conventional and molecular procedures. The results reinforced the differentiated evolutionary path of the genus Lebiasina while, at the same time, highlighted the genomic particularities that have accompanied the evolution of each species. In this sense, the repetitive components of the genome played a significant role in the differentiation of each species. It is also notable that L. minuta and L. melanoguttata, the two species that occur exclusively in the Brazilian territory, show greater chromosomal similarities to each other than to the trans-Andean sister species, L. bimaculata.(AU)

Apesar das dificuldades encontradas em se realizar análises cromossômicas em peixes de pequeno porte, os estudos citogenéticos em Lebiasinidae vêm crescendo nos últimos anos e demonstrando padrões diferenciados na evolução cromossômica entre os membros da família. Nesse contexto, o gênero Lebiasina tem mostrado preservar sua macroestrutura cariotípica, composta por 2n = 36 cromossomos, enquanto os demais gêneros geralmente apresentam 2n maiores. Este estudo tem como foco a citogenética comparativa de três espécies de Lebiasina, sendo uma delas analisada pela primeira vez aqui, através do emprego de técnicas convencionais e moleculares. Os resultados obtidos reforçam a trajetória evolutiva diferenciada do gênero Lebiasina, ao mesmo tempo em que evidenciam as particularidades genômicas que acompanham a evolução de cada uma das espécies. Neste contexto, os componentes repetitivos do genoma tiveram um papel importante na caracterização particular de cada uma das espécies. Também, é notável que L. minuta e L. melanoguttata, duas espécies que ocorrem exclusivamente no território brasileiro, apresentam maior proximidade citogenética entre elas do que com a espécie irmã transandina, L. bimaculata.(AU)

Nuclear peripheral chromatin-lamin B1 interaction is required for global integrity of chromatin architecture and dynamics in human cells

The eukaryotic genome is folded into higher-order conformation accompanied with constrained dynamics for coordinated genome functions. However, the molecular machinery underlying these hierarchically organized three-dimensional (3D) chromatin architecture and dynamics remains poorly understood. Here by combining imaging and sequencing, we studied the role of lamin B1 in chromatin architecture and dynamics. We found that lamin B1 depletion leads to detachment of lamina-associated domains (LADs) from the nuclear periphery accompanied with global chromatin redistribution and decompaction. Consequently, the inter-chromosomal as well as inter-compartment interactions are increased, but the structure of topologically associating domains (TADs) is not affected. Using live-cell genomic loci tracking, we further proved that depletion of lamin B1 leads to increased chromatin dynamics, owing to chromatin decompaction and redistribution toward nucleoplasm. Taken together, our data suggest that lamin B1 and chromatin interactions at the nuclear periphery promote LAD maintenance, chromatin compaction, genomic compartmentalization into chromosome territories and A/B compartments and confine chromatin dynamics, supporting their crucial roles in chromatin higher-order structure and chromatin dynamics.

Research Advances in Multiple Myeloma with Chromosome 1q21 Amplification / 中国实验血液学杂志

Multiple myeloma (MM) is a kind of hematologic malignancy occurring in plasma cells. Cytogenetic technique plays an important role in risk stratification of MM. 1q21 amplification is one of the common chromosomal abnormalities in MM. Studies have shown that 1q21 amplification is associated with poor prognosis in MM patients. At present, with the development of new drugs, cellular immunotherapy, and improvement of hematopoietic stem cell transplantation technology, the remission depth and survival time of MM significantly increased. Rapid and accurate identification of high-risk patients and individualized treatment according to the patient's condition is the key to improve the therapeutic effect of MM. This article reviews the mechanism of 1q21 amplification in MM and the efficacy of new drugs in the treatment of MM with 1q21 chromosome amplification.

Analysis of clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion / 中华儿科杂志

Objective: To investigate the clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion. Methods: The patients (n=10) with 16p11.2 microdeletion found in children with epilepsy treated in Beijing Children's Hospital Affiliated to Capital Medical University from January 2018 to January 2021 were collected. The clinical manifestations, gene variations and prognosis were analyzed retrospectively. Results: A total of 10 children's data were collected, including 5 male and 5 female. The onset age of epilepsy was 4.5 (4.1,5.0) months. Regarding the seizure types, 7 cases had focal seizures with secondary generalization, 2 cases had generalized seizures, and 1 case had tonic seizures and spasms. Nine cases had cluster seizure attacks and 3 cases had status epilepticus. Seven cases had focal or multifocal epileptiform discharges in interictal electroencephalogram (EEG), 3 cases had borderline or normal EEG. Brain magnetic resonance imaging showed polymicrogyria in 1 case, paraventricular leukomalacia in 1 case, delayed myelination of white matter in 3 cases, and no obvious abnormalities in the other 5 cases. The patients were followed up for 0.5-3.5 years, with 1-3 kinds of antiepileptic drugs taken orally. The case with polymicrogyria still had seizures, however the other 9 cases had seizures controlled. The age of the last seizure attack was 8 (6, 12) months. There were 6 cases with mental and motor developmental delay before epilepsy onset. During the follow-up, 7 cases were retarded to varying degrees, while 3 cases had normal development. Regarding the genetic detection methods, 7 cases underwent whole exome sequencing, 2 cases underwent whole genome copy number variation detection, and 1 case underwent whole genome sequencing. The length of the 16p11.2 deletion in 10 cases ranged from 525 to 951 kb, and all contained the PRRT2 gene intact. Six cases were de novo variants, 1 case was inherited from the mother who had a history of convulsions in early childhood, and the source of variant was not verified in 3 cases, none of whose parents had relevant phenotype. Conclusions: The epilepsy associated with 16p11.2 microdeletion is mainly induced by the heterozygous deletion of PRRT2 gene in this region, however the phenotype is usually severe, and often combined with developmental and epileptic encephalopathy. Detection of copy number variation should be emphasized in children whose etiology is considered genetic but second-generation sequencing result is negative.

Searching chromosome mosaicisms in 45, X Turner syndrome: how relevant is it?

ABSTRACT Objective: To investigate the presence of chromosome mosaicism, especially for the presence of Y derived material in 45,X women with Turner syndrome (TS). Materials and methods: FISH and PCR were performed for the presence of chromosome mosaicism and Y-derived-material and genetic findings were correlated to clinical data. Results: Thirty-one participants were enrolled: 18 (58%) had chromosome mosaicisms (FISH), Y-derived material was found in 2. Yet, SRY primer was found with PCR in only one of them and DYZ3 was not found. The most frequent clinical findings were short or webbed neck (81,82%), high-arched palate (78%), breast hypertelorism, e cubitus valgus and genu valgus (57.6%, both), short fourth metacarpals (46.9%), epicanthic folds (43.8%), shield chest (43.8%), lymphedema (37.5%), and low set ears (34.4%). Both patients with Y-derived-material had primary amenorrhea, dyslipidemia and reached the height of 150 cm despite not treated with recombinant growth hormone (GHr). One of them showed 26% of leukocytes with Y-derived material and few clinical findings. Conclusions: FISH techniques proved efficient in detecting chromosome mosaicisms and Y-derived material and searching in different tissues such as mouth cells is critical due to the possibility of tissue-specific mosaicism. Phenotypical variance in TS may be a signal of chromosome mosaicisms, especially with the presence of Y-derived material.

Cytogenetic and molecular characterization of an SRY-negative 46, XX ovotesticular DSD: a case report / Caracterização citogenética e molecular de um DDS ovotesticular 46, XX SRY-negativo: relato de caso

Introduction: Ovotesticular disorder of sex development is a rare condition characterized by the concomitant presence of testicular and ovarian tissue, and usually presents genital ambiguity. They are chromosomally heterogeneous, and cytogenetic analyses is relevant. Objective: to report a patient from Manaus, Amazonas state, Brazil, with ovotesticular disorder of sex differentiation 46,XX and SRY-negative. Case report: patient aged 19 years, first child of non-consanguineous parents, diagnosed at birth with genital ambiguity and, without correct diagnosis, was registered a male sex. The patient underwent surgery to correct bilateral cryptorchidism, orchiopexy and colpectomy. During puberty, he developed female and male sexual characteristics. Investigation at this time revealed: laboratory (normal total testosterone and estradiol as high follicle-stimulating hormone and luteinizing hormone, histopathological (right gonad, ovarian follicles and left gonad, atrophic testicles), karyotype (46, XX) and molecular (SRY-negative). Diagnosis of ovotesticular disorder of sex development was established. The patient chose to remain male and underwent bilateral mastectomy, vaginal colpectomy and bilateral gonadectomy. Currently, the patient receives hormonal replacement therapy, followup with a multi-professional approach and awaits masculinizing genitoplasty. Discussion: For OT-DSD individuals with 46, XX, the female sex is suggested as the best sex of rearing option. Unlike the reported cases, the patient chose the male sex, since the sex at registration of birth was important in his choice. Conclusion: Cytogenetic and molecular analyses allowed us to assist in the etiological diagnosis of the patient with OT-DSD. However, molecular analyses are necessary to elucidate the genes involved in the sexual determination of this patient.

Introdução: distúrbio da diferenciação do sexo ovotesticular é uma condição rara com presença concomitante de tecido testicular e ovariano, geralmente com ambiguidade genital. Os pacientes são cromossomicamente heterogêneos e a análise citogenética é fundamental. Objetivo: relatar o caso de um paciente do município de Manaus, Amazonas, portador de distúrbio da diferenciação do sexo ovotesticular 46, XX e SRY-negativo. Caso clínico: paciente de 19 anos, primeiro filho de pais não consanguíneos, que ao nascimento foi diagnosticado com ambiguidade genital, contudo, sem diagnóstico correto, foi registrado como sendo do sexo masculino. Foi submetido a cirurgias para correção da criptoquirdia bilateral, orquidopexia e colpectomia vaginal. Na puberdade, desenvolveu características sexuais feminina e masculina. Investigação diagnóstica mostrou: exames hormonais (testosterona total e estradiol normais enquanto hormônio folículo-estimulante e hormônio luteinizante elevados), histopatológicos (gônada direita, folículos ovarianos e gônadas esquerda, testículos atróficos), cariótipo (46, XX) e molecular (SRY-negativo). O diagnóstico de distúrbio da diferenciação do sexo ovotesticular foi estabelecido. O paciente optou por permanecer no sexo masculino e submeteuse à mastectomia bilateral, colpectomia vaginal e gonadectomia bilateral. Atualmente faz reposição hormonal, acompanhamento com abordagem multiprofissional e aguarda pela genitoplastia masculinizante. Discussão: aos indivíduos DDS-OT com 46, XX é sugerido como a melhor opção de sexo, o feminino. Diferentemente dos casos relatados, o paciente optou por permanecer no sexo masculino, visto que o registro de nascimento foi importante para a sua escolha. Conclusão: análises citogenéticas e moleculares permitiu auxiliar no diagnóstico etiológico do paciente com DDS-OT, contudo, análises moleculares são necessárias para elucidação de genes envolvidos na determinação sexual desse paciente.

Effects of trichostatin A on FHIT and WWOX genes expression, cell growth inhibition and apoptosis induction in hepatocellular carcinoma WCH 17 cell line

Previously, we evaluated the effect of trichostatin A (TSA) on the expression of DNA methyltransferase 1 (DNMT1) in Hepatocellular Carcinoma (HCC). Fragile histidine triad (FHIT) and WW domain-containing oxidoreductase (WWOX) are two of the most common down-regulated genes in many cancers located on chromosome 3p14.2 and 16q23.3-24.1 respectively. The aim of the current study was to assess the effect of TSA on these genes expression, cell growth, and apoptosis in HCC WCH 17 cell. The cells were seeded and treated with TSA at different times. Then, MTT assay, flow cytometry, and qRT-PCR were achieved to determine viability, apoptosis and gene expression respectively. Cell growth was significantly inhibited, 92 to 36% after 24 h, 86 to 28% after 48 h, and 78 to 24% after 72 h. The results of flow cytometry confirmed that TSA increased apoptosis compared to the control group, the apoptosis percentage increased to 12%, 16%, and 18% in comparison to control groups (2%). Significant up-regulation of the genes was observed in all treated groups. We concluded that re-expression of silenced WWOX and FHIT genes could be achieved by TSA resulting in cell growth inhibition and apoptosis induction in WCH 17 cell.

Banded chromosome images recognition based on dense convolutional network with segmental recalibration / 生物医学工程学杂志

Human chromosomes karyotyping is an important means to diagnose genetic diseases. Chromosome image type recognition is a key step in the karyotyping process. Accurate and efficient identification is of great significance for automatic chromosome karyotyping. In this paper, we propose a model named segmentally recalibrated dense convolutional network (SR-DenseNet). In each stage of the model, the dense connected network layers is used to extract the features of different abstract levels of chromosomes automatically, and then the concatenation of all the layers which extract different local features is recalibrated with squeeze-and-excitation (SE) block. SE blocks explicitly construct learnable structures for importance of the features. Then a model fusion method is proposed and an expert group of chromosome recognition models is constructed. On the public available Copenhagen chromosome recognition dataset (G-bands) the proposed model achieves error rate of only 1.60%, and with model fusion the error further drops to 0.99%. On the Padova chromosome dataset (Q-bands) the model gets the corresponding error rate of 6.67%, and with model fusion the error further drops to 5.98%. The experimental results show that the method proposed in this paper is effective and has the potential to realize the automation of chromosome type recognition.

Prenatal diagnosis of a fetus with chromosome 18p deletion and duplication / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of chromosomal microarray analysis (CMA) to verify a fetus with partial 18p deletion signaled by non-invasive prenatal testing.@*METHODS@#G-banding chromosomal karyotyping analysis was carried out on amniotic fluid sample of the fetus and peripheral blood samples from the parents. Amniotic DNA was also subjected to CMA analysis. The fetus was also subjected to systematic ultrasound scan.@*RESULTS@#The fetus was found to have a karyotype of 46,XX,18p+. CMA has revealed a 5 Mb deletion at 18p11.32-p11.31, a 2.9 Mb duplication at 18p11.31-p11.23, and a 2.5 Mb duplication at 18p11.23-p11.22. No chromosomal aberration or microdeletion/microduplication was detected in either parent.@*CONCLUSION@#Non-invasive prenatal testing and CMA are both sensitive for the detection of chromosomal microdeletions and microduplications. CMA can help with clarification of genotype-phenotype correlation and facilitate prenatal diagnosis and genetic counseling for the family.

Experience and lessons on guiding and governing clinical applications of chromosome microarray analysis in the United States / 中华医学遗传学杂志

Chromosome microarray analysis (CMA) has become the first-tier testing for chromosomal abnormalities and copy number variations (CNV). This review described the clinical validation of CMA, the development and updating of technical standards and guidelines and their diagnostic impacts. The main focuses were on the development and updating of expert consensus, practice resources, and a series of technical standards and guidelines through systematic review of case series with CMA application in the literature. Expert consensus and practice resource supported the use of CMA as the first-tier testing for detecting chromosomal abnormalities and CNV in developmental and intellectual disabilities, multiple congenital anomalies and autism. The standards and guidelines have been applied to pre- and postnatal testing for constitutional CNV and tumor testing for acquired CNV. CMA has significantly improved the diagnostic yields but still needs to overcome its technical limitations and face challenges of new technologies. Guiding and governing CMA through expert consensus, practice resource, standards and guidelines in the United States has provided effective and safe diagnostic services to patients and their families, reliable diagnosis on related genetic diseases for clinical database and basic research, and references for clinical translation of new technologies.

Clinical and genetic analysis of a child with 2q37 deletion syndrome resulting from a translocation involving chromosome satellite / 中华医学遗传学杂志

OBJECTIVE@#To carry out cyto- and molecular genetic testing for a child featuring facial dysmorphism and attention deficit and hyperactive disorder.@*METHODS@#The child was subjected to routine peripheral blood lymphocyte chromosomal karyotyping, fluorescence in situ hybridization (FISH) and single nucleotide polymorphism array (SNP-array) analyses.@*RESULTS@#The child's facial dysmorphism included low-set ears, curly ear auricle, protuberance of eyebrow arch, nostril notch, short and flat philtrum and thin upper lip. SNP-array revealed that he has carried a 4.883 Mb deletion at 2q37. His chromosomal karyotype was ultimately determined as 45, XY, der(2;21) (2pter→ 2q37.3::21p13→ 21p10::20p10→ 20pter), der(20) (21qter→ 21q10::20q10→ 20qter).@*CONCLUSION@#A rare case of 2q37 deletion syndrome involving three chromosomes was discovered. Combined use of various cyto- and molecular genetic techniques is crucial for the diagnosis of chromosomal abnormalities with complex structures.

Preliminary study on the application of third-generation sequencing technology for the detection of chromosomal aneuploidies / 中华医学遗传学杂志

OBJECTIVE@#To apply nanopore third-generation sequencing for the detection of chromosomal aneuploidy samples, and explore its performance and application prospects.@*METHODS@#DNA extracted from two human cell lines with X chromosome monosomy and 22.5 Mb deletion in 7q11.23-q21.3 region was sequenced with a MinION sequencer, and the results were analyzed.@*RESULTS@#Respectively, 555 872 and 2 679 882 reads were obtained from the two samples within 24 hours, with genome coverage being 53.75% and 88.63%. With a sequencing depth of 0.81× and 2.40× , respectively, the abnormal chromosomal regions could be detected by comparative analysis using Minimap2.@*CONCLUSION@#With low-depth whole genome sequencing, the use of nanopore third-generation sequencing is expected to complete the detection and analysis of chromosomal aneuploidy samples within 24 hours, but its further application and promotion needs to overcome the cost constraints.

Value of non-invasive prenatal testing for the detection of fetal chromosomal copy number variations / 中华医学遗传学杂志

OBJECTIVE@#To explore the value of non-invasive prenatal testing (NIPT) for the detection of fetal chromosome copy number variations (CNVs).@*METHODS@#Clinical data of 18 661 pregnant women who underwent NIPT were collected. For fetuses suspected for carrying CNVs, amniotic fluid samples were collected for chromosomal karyotyping and/or chromosomal microarray analysis (CMA).@*RESULTS@#Among all samples, NIPT suggested that 58 fetuses carried trisomy 21, 18 carried trisomy 18, 19 carried trisomy 13, 1 carried trisomies 18 and 21. Eighty eight women accepted invasive prenatal diagnosis. The results of CMA in 59 cases were consistent with those of NIPT, which yielded a consistency rate of 67.05%. In addition, 37 cases of fetal CNVs were detected by NIPT, of which 19 (15 microdeletions and 4 microduplications) have accepted invasive prenatal diagnosis. In 14 cases, the results were consistency with those of NIPT, with a consistent rate of 73.68%.@*CONCLUSION@#NIPT features high sensitivity and accuracy. Invasive prenatal diagnosis should be considered for CNVs detected by NIPT, and by tracing its parental origin, it can provide guidance for clinical practice.