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1.
PLoS One ; 15(8): e0238245, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32845907

RESUMO

To study the detection limits of chromosomal microaberrations in non-invasive prenatal testing with aim for five target microdeletion syndromes, including DiGeorge, Prader-Willi/Angelman, 1p36, Cri-Du-Chat, and Wolf-Hirschhorn syndromes. We used known cases of pathogenic deletions from ISCA database to specifically define regions critical for the target syndromes. Our approach to detect microdeletions, from whole genome sequencing data, is based on sample normalization and read counting for individual bins. We performed both an in-silico study using artificially created data sets and a laboratory test on mixed DNA samples, with known microdeletions, to assess the sensitivity of prediction for varying fetal fractions, deletion lengths, and sequencing read counts. The in-silico study showed sensitivity of 79.3% for 10% fetal fraction with 20M read count, which further increased to 98.4% if we searched only for deletions longer than 3Mb. The test on laboratory-prepared mixed samples was in agreement with in-silico results, while we were able to correctly detect 24 out of 29 control samples. Our results suggest that it is possible to incorporate microaberration detection into basic NIPT as part of the offered screening/diagnostics procedure, however, accuracy and reliability depends on several specific factors.


Assuntos
Mapeamento Cromossômico/métodos , Limite de Detecção , Teste Pré-Natal não Invasivo/métodos , Sequenciamento Completo do Genoma/métodos , Ácidos Nucleicos Livres/análise , Deleção Cromossômica , Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 1/genética , Síndrome do Miado do Gato/diagnóstico , Síndrome do Miado do Gato/genética , Síndrome de DiGeorge/diagnóstico , Síndrome de DiGeorge/genética , Feminino , Humanos , Síndrome de Prader-Willi/diagnóstico , Síndrome de Prader-Willi/genética , Gravidez , Cuidado Pré-Natal , Síndrome de Wolf-Hirschhorn/diagnóstico , Síndrome de Wolf-Hirschhorn/genética
2.
Hum Genet ; 139(11): 1417-1427, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32488466

RESUMO

An inverted duplication with a terminal deletion (inv-dup-del) is one of the complex constitutional structural rearrangements that can occur in a chromosome. Although breakages of dicentric chromosome have been suggested, the precise mechanism of this is yet to be fully understood. In our present study, we investigated the genomic structure of 10 inv-dup-del cases to elucidate this mechanism. Two recurrent 8p inv-dup-del cases harbored a large copy-number-neutral region between the duplication and deletion in common. Although the other non-recurrent cases did not appear to have this copy-number-neutral region, refined sequencing analysis identified that they contained a small intervening region at the junction between the inverted and non-inverted segment. The size of this small intervening region ranged from 1741 to 3728 bp. Combined with a presence of microhomology at the junction, a resolution of the replication fork stalling through template switching within the same replication fork is suggested. We further observed two cases with mosaicism of the dicentric chromosome and various structural rearrangements related to the dicentric chromosome. Refined analysis allowed us to identify different breakpoints on the same chromosome in the same case, implicating multiple rounds of U-type formation and its breakage. From these results, we propose that a replication-based mechanism generates unstable dicentric chromosomes and that their breakage leads to the formation of inv-dup-dels and other related derivative chromosomes.


Assuntos
Transtornos Cromossômicos/genética , Inversão Cromossômica/genética , Cromossomos/genética , Duplicação Gênica/genética , Deleção de Sequência/genética , Deleção Cromossômica , Replicação do DNA/genética , Humanos , Mosaicismo
3.
Medicine (Baltimore) ; 99(26): e20863, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32590788

RESUMO

INTRODUCTION: The infertile male individuals carrying the Y-autosome translocations are seldom reported in clinic. Herein, we described a severe oligozoospermic male with rare unbalanced Y;3 translocation transmitted through 3 generations. PATIENT CONCERNS: A 33-year-old Chinese male was referred for infertility consultation in our center after 10 years' primary infertility. He was diagnosed as severe oligozoospermia according to the semen analysis. DIAGNOSIS: G-banding analysis initially described the karyotype as 46, XY, add (3) (p26) for the patient, and his wife's karyotype was 46, XX. The chromosomal microarray analysis identified 3.81Mb and 0.29Mb duplications in Yq11.223q11.23 and Yq12, separately. No deletions were detected in azoospermia factors (AZF)a, AZFb and AZFc. Fluorescence in situ hybridization analysis further confirmed the existence of sex-determining region Y gene and verified that Yq12 was translocated to the terminal short arm of chromosome 3(3p26). INTERVENTIONS: The couple chose intracytoplasmic sperm injection to get their offspring. The wife underwent amniocentesis for cytogenetic analysis but suffered termination of pregnancy due to premature rupture of membranes. OUTCOMES: The karyotype of the patient was finally described as 46, X, der(3)t(Y;3)(q11.22;p26). His father and the aborted fetus showed the same karyotypes as the patient. CONCLUSION: Our study not only enriched the karyotype-phenotype correlation of Y-autosome translocation, but also strengthened the critical roles of molecular genetic techniques in identifying the chromosomal breakpoints and regions involved.


Assuntos
Transtornos Cromossômicos/complicações , Infertilidade Masculina/genética , Adulto , Transtornos Cromossômicos/genética , Citogenética/métodos , Humanos , Hibridização in Situ Fluorescente/métodos , Infertilidade Masculina/diagnóstico , Masculino
4.
Adv Exp Med Biol ; 1195: 163-166, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32468472

RESUMO

INTRODUCTION: Chromosome 18q deletion syndrome (18q-) is a rare chromosomal disorder with phenotypic variability, including mental deficiency, short stature, hypotonia, cleft palate, and hearing impairment. We present a case with features of 18q- syndrome who had combined 18q partial monosomy and 18p partial trisomy. MATERIAL AND METHODS: A 50-year-old female patient was examined during the genetic counseling of her brother. She had a history of congenital cleft palate and developmental deficiency with hypotonia, hearing loss, and epilepsy until adulthood. Her family history was free of related cases. Karyotype analysis and comparative genomic hybridization array (aCGH) were performed in patient's blood samples. RESULTS: Clinical examination showed features of 18q- syndrome including hypotonia and tremor. Neuropsychological deficiency of moderate cognitive disorder was noticed. The patient's karyotype was normal. The aCGH analysis revealed 8 Mb deletion (del18q22.3q23) and 7.2 Mb duplication (dup18p11.32p11.23). CONCLUSION: Almost all patients' clinical features were associated with 18q- syndrome. There are very few reported cases with similar genotype possibly caused by a de novo unequal recombination mechanism.


Assuntos
Deleção Cromossômica , Transtornos Cromossômicos/genética , Duplicação Cromossômica/genética , Cromossomos Humanos Par 18/genética , Anormalidades Craniofaciais/genética , Hibridização Genômica Comparativa , Feminino , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade , Fenótipo , Síndrome
5.
Gene ; 753: 144816, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32473250

RESUMO

Hemizygosity of the MIR17HG gene encoding the miR-17 ~ 92 cluster is associated with Feingold syndrome 2 characterized by intellectual disability, skeletal abnormalities, short stature, and microcephaly. Here, we report on a female with a de novo 13q31.3 microduplication encompassing MIR17HG but excluding GPC5. She presented developmental delay, skeletal and digital abnormalities, and features such as tall stature and macrocephaly mirroring those of Feingold syndrome 2 patients. The limited extent of the proband's rearrangement to the miR cluster and the corresponding normal expression level of the neighboring GPC5 in her cells, together with previously described data on affected individuals of two families carrying overlapping duplications of the miR-17 ~ 92 cluster that comprise part of GPC5, who likewise presented macrocephaly, developmental delay, as well as skeletal, digital and stature abnormalities, allow to define a new syndrome due to independent microduplication of the miR-17 ~ 92 cluster.


Assuntos
Transtornos Cromossômicos/genética , Pálpebras/anormalidades , Deficiência Intelectual/genética , Deformidades Congênitas dos Membros/genética , MicroRNAs/genética , Microcefalia/genética , Fístula Traqueoesofágica/genética , Adolescente , Deleção Cromossômica , Cromossomos Humanos Par 13/genética , Hibridização Genômica Comparativa/métodos , Deficiências do Desenvolvimento/genética , Nanismo/genética , Feminino , Duplicação Gênica/genética , Glipicanas/genética , Glipicanas/metabolismo , Humanos , Fenótipo
6.
Fertil Steril ; 113(4): 853-864, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32228881

RESUMO

OBJECTIVE: To determine whether the incidence of chromosomal abnormalities in blastocysts is higher in patients with idiopathic recurrent pregnancy loss (iRPL) who underwent preimplantation genetic testing for aneuploidy (PGT-A) than in those who underwent preimplantation genetic testing for monogenic defects (PGT-M). DESIGN: Retrospective cohort study. SETTING: University-affiliated reproductive center. PATIENT(S): A total of 62 patients with iRPL underwent 101 PGT-A cycles (iRPL group), and 212 patients underwent 311 PGT-M cycles (control group). INTERVENTIONS(S): Blastocyst biopsy and comprehensive chromosome screening technologies, including single-nucleotide polymorphism microarrays and next-generation sequencing. MAIN OUTCOME MEASURE(S): Incidence of chromosomal abnormalities in blastocysts and clinical miscarriage (CM) rate. RESULT(S): Stratification analysis by maternal age showed an increased incidence of chromosomal abnormalities in the iRPL group aged ≤35 years (48.9% vs. 36.9%), whereas no significant increase was found in the iRPL group aged >35 years (66.9% vs. 61.4%). After transfer of euploid embryos, women aged ≤35 years with iRPL exhibited an increased CM rate compared with the control group (26.1% vs. 3.1%). CONCLUSION(S): Young patients with iRPL have a significantly higher rate of chromosomal abnormalities in blastocysts compared with patients with no or sporadic CM. Although euploid embryos were transferred after PGT-A, young patients with iRPL had a higher CM rate, which may indicate that chromosomal abnormalities might not be the only causal factor for iRPL. Therefore, the role of PGT-A in iRPL still needs to be clarified.


Assuntos
Aborto Habitual/genética , Aneuploidia , Blastocisto/fisiologia , Aberrações Cromossômicas/embriologia , Diagnóstico Pré-Implantação/métodos , Aborto Habitual/diagnóstico , Adulto , Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/genética , Estudos de Coortes , Feminino , Testes Genéticos/métodos , Humanos , Gravidez , Estudos Retrospectivos
8.
Zhonghua Fu Chan Ke Za Zhi ; 55(2): 106-111, 2020 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-32146739

RESUMO

Objective: To evaluate the efficacy of cell free DNA (cf-DNA) screening in prenatal care by analyzing the follow-up information and pregnancy outcomes. Methods: All cf-DNA cases conducted in Women's Hospital of Nanjing Medical University from August 2011 to December 2017 were enrolled. The general information of the pregnancies, cf-DNA results, confirmatory testing results, and the follow-up results were collected. The pregnancy outcomes were analyzed in cases with low risk cf-DNA results as well as with high risk results for common trisomies, which were trisomy 21 (T21), trisomy 18 (T18), and trisomy 13 (T13). The sensitivity, specificity, positive predictive value and negative predictive value of cf-DNA screening were calculated. Results: (1) A total of 43 615 cf-DNA cases were involved, with 44 cases (0.10%, 44/43 615) test failure results, 314 cases (0.72%, 314/43 571) high risk results for common trisomies and 43 257 cases (99.27%, 43 257/43 571) low risk results. (2) Among 277 cases (88.21%, 277/314) high risk cases were successfully followed up, and 228 cases (82.31%, 228/277) underwent invasive confirmatory prenatal diagnosis. In the low risk results, 36 826 cases (85.13%, 36 826/43 257) were successfully followed up, and 572 (1.55%, 572/36 826) cases were found to have adverse pregnancy outcomes, among which 4 false negative cf-DNA results were confirmed. (3) In the 37 103 successfully followed up cf-DNA cases, the sensitivity for T21, T18, T13 were calculated as 97.96%, 96.67% and 100.00%, respectively; the specificity for T21, T18, T13 were calculated as 99.96%, 99.95% and 99.95%, respectively. The positive predictive value for T21, T18, T13 were calculated as 90.57%, 63.04% and 17.39%, respectively. The negative predictive value for T21, T18, T13 were calculated as 99.99%, 99.98% and 100.00%. Conclusions: Cf-DNA is effective in detecting common trisomies, with a high sensitivity and specificity. However, the follow-up information revealed several potential limitations in current clinical practice, such as a number of cases with high risk results rejected invasive confirmatory testing, as well as the genetic diagnostic results for most low risk cases with an adverse pregnancy outcome aren't obtained. Genetic counseling and the follow-up for all the cf-DNA cases should be emphasized in the future.


Assuntos
Ácidos Nucleicos Livres , Transtornos Cromossômicos/diagnóstico , Diagnóstico Pré-Natal/métodos , Trissomia/diagnóstico , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 18/genética , Feminino , Seguimentos , Testes Genéticos/métodos , Humanos , Valor Preditivo dos Testes , Gravidez , Resultado da Gravidez , Sensibilidade e Especificidade , Trissomia/genética , Síndrome da Trissomia do Cromossomo 13 , Síndrome da Trissomía do Cromossomo 18 , Ultrassonografia Pré-Natal
9.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(4): 389-391, 2020 Apr 10.
Artigo em Chinês | MEDLINE | ID: mdl-32219819

RESUMO

OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) for the analysis of 824 samples from miscarriage or stillbirth. METHODS: Copy number variations (CNVs) in the abortic chorionic villi or stillbirth tissues were detected by CMA. RESULTS: All specimens were successfully analyzed, among which 381 (46.2%) were diagnosed with chromosomal abnormalities, which included 312 (81.9%) numerical abnormalities, 66 (17.3%) structural abnormalities and 3 (0.8%) uniparental disomies. Among numerical chromosomal abnormalities, aneuploidies was most common (92.0%), with trisomy 16 and 45,X accounting for 41 (13.1%) and 63 (20.2%) of the cases, respectively. Among the 66 structural chromosomal aberrations, there were 26 (39.4%) CNVs duplications, 20 (30.3%) CNVs deletions, and 20 (30.3%) CNVs duplication and deletions. 33 CNVs were predicted as have a high chance to lead to a disease. CONCLUSION: CMA is a reliable, robust, and high-resolution method for the analysis of miscarriage or stillbirth samples. Numerical aberrations, in particular chromosomal aneuploides, are the main cause for spontaneous abortions and stillbirths.


Assuntos
Aborto Espontâneo/genética , Aberrações Cromossômicas , Transtornos Cromossômicos , Análise em Microsséries , Natimorto/genética , Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/genética , Variações do Número de Cópias de DNA , Feminino , Humanos , Gravidez
10.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(4): 392-396, 2020 Apr 10.
Artigo em Chinês | MEDLINE | ID: mdl-32219820

RESUMO

OBJECTIVE: To assess the value of combined chromosomal karyotyping and chromosomal microarray analysis (CMA) for prenatal diagnosis. METHODS: G-banding karyotyping and CMA were simultaneously performed on 546 women who were subjected to amniocentesis during middle pregnancy. RESULTS: In total 82 cases were detected with chromosomal abnormalities. The two methods were consistent in 43 cases, which included 14 trisomy 21, 6 trisomy 18, 1 trisomy 13, 14 sex chromosomal aneuploidies, 4 chromosomal deletions, 3 chromosomal duplications and 1 sex chromosomal mosaicism. Fifteen fetuses with chromosomal abnormalities detected by CMA were missed by karyotyping analysis, which included 9 microdeletions and 6 microduplications. Sixteen fetuses with chromosomal abnormalities detected by karyotyping analysis were missed by CMA, which included 15 chromosomal translocations and 1 sex chromosomal mosaicism. In 7 cases, the results of karyotyping analysis and CMA were inconsistent. One supernumerary marker chromosome detected by karyotyping analysis was verified by CMA as 9p13.1p21.1 duplication. CONCLUSION: Combined chromosomal karyotyping and CMA can significantly improve the detection rate for chromosomal abnormalities, which has a great value for prenatal diagnosis.


Assuntos
Transtornos Cromossômicos , Cariotipagem , Análise em Microsséries , Diagnóstico Pré-Natal , Aberrações Cromossômicas , Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/genética , Feminino , Humanos , Gravidez
11.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(4): 405-409, 2020 Apr 10.
Artigo em Chinês | MEDLINE | ID: mdl-32219823

RESUMO

OBJECTIVE: To carry out genetic testing for 3 fetuses with abnormal prenatal screening. METHODS: Fetal ultrasound, karyotype analysis, single nucleotide polymorphism (SNP) array and fluorescence in situ hybridization were performed. RESULTS: Abnormalities of chromosome 22 were found with all 3 fetuses. Fetus 1 harbored a 7.1 Mb deletion in 22q13.2q13.33 region, which involved 54 OMIM genes including SHANK3 and FBLN1. Fetus 2 had a mosaicism karyotype, with 12% of cells harboring a 6.6 Mb deletion in 22q13.31q13.33, covering 48 OMIM genes such as SHANK3 and PPARA, and 5% of cells harboring a 26.1 Mb duplication in 22q11.1q13.2 involving 285 OMIM genes. Fetus 3 carried a tandem duplication of 1.7 Mb in 22q11.1q11.21, which involved 10 OMIM genes including CECR1, CECR2 and ATP6V1E1. No abnormality was found in the three couples by chromosomal karyotyping and SNP array analysis. CONCLUSION: The severity of diseases caused by chromosome 22 abnormalities not only depends on the range of the deletion or duplication, but is also closely related to chromosome structure, gene dose and genetic environment. Combined ultrasonography and various genetic testing techniques in prenatal diagnosis can greatly increase the detection rate of genetic diseases with substantial phenotypic variation.


Assuntos
Transtornos Cromossômicos/diagnóstico , Cromossomos Humanos Par 22/genética , Testes Genéticos , Cariotipagem , Diagnóstico Pré-Natal , Ultrassonografia Pré-Natal , Aberrações Cromossômicas , Deleção Cromossômica , Transtornos Cromossômicos/genética , Feminino , Feto , Humanos , Hibridização in Situ Fluorescente , Gravidez , Fatores de Transcrição
13.
Hum Genet ; 139(4): 531-543, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32030560

RESUMO

We present a comprehensive clinically oriented workflow for large-insert genome sequencing (liGS)-based nucleotide level resolution and interpretation of de novo (dn) apparently balanced chromosomal abnormalities (BCA) in prenatal diagnosis (PND). Retrospective or concomitant with conventional PND and liGS, molecular and newly developed clinically inspired bioinformatic tools (TAD-GConTool and CNV-ConTool) are applied to analyze and assess the functional and phenotypic outcome of dn structural variants (dnSVs). Retrospective analysis of four phenotype-associated dnSVs identified during conventional PND precisely reveal the genomic elements disrupted by the translocation breakpoints. Identification of autosomal dominant disease due to the disruption of ANKS1B and WDR26 by t(12;17)(q23.1;q21.33)dn and t(1;3)(q24.11;p25.3)dn breakpoints, respectively, substantiated the proposed workflow. We then applied this workflow to two ongoing prenatal cases with apparently balanced dnBCAs: 46,XX,t(16;17)(q24;q21.3)dn referred for increased risk on combined first trimester screening and 46,XY,t(2;19)(p13;q13.1)dn referred due to a previous trisomy 21 pregnancy. Translocation breakpoints in the t(16;17) involve ANKRD11 and WNT3 and disruption of ANKRD11 resulted in KBG syndrome confirmed in postnatal follow-up. Breakpoints in the t(2;19) are within ATP6V1B1 and the 3' UTR of CEP89, and are not interpreted to cause disease. Genotype-phenotype correlation confirms the causative role of WDR26 in the Skraban-Deardorff and 1q41q42 microdeletion phenocopy syndromes, and that disruption of ANKS1B causes ANKS1B haploinsufficiency syndrome. In sum, we show that an liGS-based approach can be realized in PND care providing additional information concerning clinical outcomes of dnBCAs in patients with such rearrangements.


Assuntos
Anormalidades Múltiplas , Doenças do Desenvolvimento Ósseo , Transtornos Cromossômicos , Cromossomos Humanos/genética , Facies , Genes Dominantes , Deficiência Intelectual , Diagnóstico Pré-Natal , Anormalidades Dentárias , Translocação Genética , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Adolescente , Adulto , Doenças do Desenvolvimento Ósseo/diagnóstico , Doenças do Desenvolvimento Ósseo/genética , Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/genética , Feminino , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Masculino , Gravidez , Anormalidades Dentárias/diagnóstico , Anormalidades Dentárias/genética , Fluxo de Trabalho
14.
Gene ; 738: 144461, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32057927

RESUMO

Down syndrome is one of the most common chromosomal disorders and yet our understanding about the dysregulated genes in this disease is limited. Through this case study, we investigated the gene expression profile of primary amniotic fluid mesenchymal stem cells (AFMSCs) isolated from the amniotic sac of monozygotic twins discordant for trisomy 21 with one fetal hydrops at 17 weeks of gestation. AFMSCs were cultured to analyze the gene expression profiles for the human transcriptome array. Gene ontology was used to evaluate dysregulated gene functions. Total 25,799 genes were identified such that 65 were up-regulated (0.25%) and 111 were down-regulated (0.43%) with a log2 fold change trisomy 21/euploidy (log2 [FC]) > 1, p < 0.01). 16 genes were selected and verified by qRT-PCR, which showed compatible result with transcriptome array. At the chromosome level, chromosome 21 was found to carry the highest percentage of up-regulated genes (2.13%, 7/329 genes) with the highest mean log2 [FC] (0.23, p < 10-5), particularly on 21q22.3. There were eight segments with significant mean log2 [FC] on chromosomes 1, 6, 11, and 21 for upregulation, and on chromosomes 16, 17, and 19 for downregulation, indicating a pattern of dysregulated genes clustering in domains along the genome. Gene ontology showed the identified genes associated with extracellular matrix organization (11 genes, p = 5.1 × 10-6) and central nervous system development (8 genes, p = 6.0 × 10-5). Using transcriptome analysis of the AFMSCs of monozygotic twins discordant for trisomy 21, we report the dysregulated genes involved in Down syndrome, their predominance on chromosome 21, and the cluster pattern on the whole genome.


Assuntos
Síndrome de Down/genética , Perfilação da Expressão Gênica/métodos , Análise em Microsséries/métodos , Líquido Amniótico , Transtornos Cromossômicos/genética , Doenças em Gêmeos/genética , Feminino , Ontologia Genética , Genoma , Genótipo , Humanos , Células-Tronco Mesenquimais/fisiologia , Fenótipo , Gravidez , Transcriptoma/genética , Trissomia/genética , Gêmeos Monozigóticos/genética
15.
Cytogenet Genome Res ; 160(2): 80-84, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32018271

RESUMO

Unbalanced X;autosome translocations are a rare occurrence with a wide variability in clinical presentation in which the X chromosome unbalance is usually mitigated by a favorable X inactivation pattern. In most cases, this compensation mechanism is incomplete, and the patients show a syndromic clinical presentation. We report the case of a family with 4 women, of 3 different generations, carrying an unbalanced X;7 translocation with a derivative X;7 chromosome and showing a skewed X inactivation pattern with a preferential activation of the normal X. None of the carriers show intellectual disability, and all of them have a very mild clinical presentation mainly characterized by gynecological/hormonal issues and autoimmune disorders. We underline the necessity of family testing for a correct genetic consultation, especially in the field of prenatal diagnosis. We indeed discuss the fact that X;autosome translocations may lead to self-immunization, as skewed X chromosome inactivation has already been proved to be related to autoimmune disorders.


Assuntos
Doenças Autoimunes/genética , Transtornos Cromossômicos/genética , Cromossomos Humanos X/genética , Translocação Genética , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Linhagem , Fenótipo , Gravidez , Inativação do Cromossomo X
16.
Cytogenet Genome Res ; 160(2): 57-62, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32036363

RESUMO

This study aims to investigate the value of chromosomal microarray analysis (CMA) and whole exome sequencing (WES) in fetuses with increased nuchal translucency (defined as NT above the 95th centile for the crown-rump length). A total of 374 singleton pregnancies with gestational ages ranging from 11 to 13 + 6 weeks were investigated. Ultrasound displayed increased NT and no detectable structural malformations in these fetuses. Pregnancies were divided into 4 groups according to the NT values: 95th centile-3.4 mm (114 cases); 3.5-4.4 mm (150 cases); 4.5-5.4 mm (55 cases); and ≥5.5 mm (55 cases). The possible chromosomal anomalies were all analyzed by CMA first. Furthermore, 24 cases with increased NT but negative CMA results were investigated by WES, and the outcomes were followed up. Among all the 374 cases, causative genetic defects were detected in 100/374 (26.7%) of the cases along with 9 variants of unknown significance (VOUS) by CMA. CMA testing yielded 30 pathogenic variants (30/55), accounting for a detection rate of 54.5%, and 1 VOUS in the group of NT ≥5.5 mm, indicating the highest detection rate in the 4 groups. The 24 cases of the CMA negative sub-cohort with WES analysis further yielded 2 VOUS and 3 likely pathogenic variants, including 2 dominant de novo mutations in SOS1 and ECE1 and 1 recessive inherited compound heterozygous mutation in PIGN, which are associated with cardiac defects. All 3 cases opted for termination of pregnancy (TOP). In addition, 2 cases with increased NT were negative by both CMA and WES analysis, and fetal demise occurred. In conclusion, for the investigation of fetuses with increased NT exome sequencing is suggested to be considered in cases with negative CMA findings. However, appropriate genetic counseling should be given to optimizing its utilization in prenatal diagnosis.


Assuntos
Transtornos Cromossômicos/diagnóstico por imagem , Medição da Translucência Nucal/métodos , Diagnóstico Pré-Natal/métodos , Sequenciamento Completo do Exoma/métodos , Adulto , Transtornos Cromossômicos/genética , Feminino , Aconselhamento Genético , Idade Gestacional , Humanos , Idade Materna , Análise de Sequência com Séries de Oligonucleotídeos , Gravidez , Ultrassonografia , Adulto Jovem
17.
Cytogenet Genome Res ; 160(1): 11-17, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31982875

RESUMO

Small supernumerary marker chromosomes (sSMCs) are characterized as additional centric chromosome fragments which are too small to be classified by cytogenetic banding alone and smaller than or equal to the size of chromosome 20 of the same metaphase spread. Here, we report a patient who presented with slight neutropenia and oral aphthous ulcers. A mosaic de novo sSMC, which originated from 5 discontinuous regions of chromosome 8, was detected in the patient. Formation of the sSMC(8) can probably be explained by a multi-step process beginning with maternal meiotic nondisjunction, followed by post-zygotic anaphase lag, and resulting in chromothripsis. Chromothripsis is a chromosomal rearrangement which occurs by breakage of one or more chromosomes leading to a fusion of surviving chromosome pieces. This case is a good example for emphasizing the importance of conventional karyotyping from PHA-induced peripheral blood lymphocytes and examining tissues other than bone marrow in patients with inconsistent genotype and phenotype.


Assuntos
Cromossomos Humanos Par 8/genética , Cromossomos Humanos Par 8/ultraestrutura , Neutropenia/genética , Úlceras Orais/genética , Estomatite Aftosa/genética , Pré-Escolar , Aberrações Cromossômicas , Transtornos Cromossômicos/genética , Citogenética , Feminino , Marcadores Genéticos , Genótipo , Humanos , Cariotipagem , Linfócitos/metabolismo , Metáfase , Mosaicismo , Neutropenia/complicações , Neutropenia/diagnóstico , Análise de Sequência com Séries de Oligonucleotídeos , Úlceras Orais/complicações , Úlceras Orais/diagnóstico , Fenótipo , Estomatite Aftosa/complicações , Estomatite Aftosa/diagnóstico
18.
J Hum Genet ; 65(4): 397-410, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31911611

RESUMO

Molecular diagnosis of rare inherited palmoplantar keratoderma (PPK) is still challenging. We investigated at the clinical and genetic level a consanguineous Tunisian family presenting an autosomal dominant atypical form of transgrediens and progrediens PPK to better characterize this ultrarare disease and to identify its molecular etiology. Whole-exome sequencing (WES), filtering strategies, and bioinformatics analysis have been achieved. Clinical investigation and follow up over 13 years of this Tunisian family with three siblings formerly diagnosed as an autosomal recessive form of Mal de Melela-like conducted us to reconsider its initial phenotype. Indeed, the three patients presented clinical features that overlap both Mal de Meleda and progressive symmetric erythrokeratoderma (PSEK). The mode of inheritance was also reconsidered, since the mother, initially classified as unaffected, exhibited a similar expression of the disease. WES analysis showed the absence of potentially functional rare variants in known PPKs or PSEK-related genes. Results revealed a novel heterozygous nonsynonymous variant in cadherin-12 gene (CDH12, NM_004061, c.1655C > A, p.Thr552Asn) in all affected family members. This variant is absent in dbSNP and in 50 in-house control exomes. In addition, in silico analysis of the mutated 3D domain structure predicted that this variant would result in cadherin-12 protein destabilization and thermal instability. Functional annotation and biological network construction data provide further supporting evidence for the potential role of CDH12 in the maintenance of skin integrity. Taken together, these results suggest that CDH12 gene is a potential candidate gene for an atypical presentation of an autosomal dominant form of transgrediens and progrediens PPK.


Assuntos
Caderinas , Transtornos Cromossômicos , Eritroceratodermia Variável , Genes Dominantes , Mutação de Sentido Incorreto , Adulto , Idoso , Caderinas/química , Caderinas/genética , Transtornos Cromossômicos/genética , Transtornos Cromossômicos/patologia , Simulação por Computador , Eritroceratodermia Variável/genética , Eritroceratodermia Variável/patologia , Feminino , Humanos , Masculino , Domínios Proteicos , Pele/patologia , Sequenciamento Completo do Exoma
19.
J Clin Ultrasound ; 48(4): 240-243, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31994200

RESUMO

We report the case of a fetus with sonographic characteristics of Beckwith-Wiedemann syndrome (BWS). A 30-year-old gravida 2 para 1 was referred to our fetal medicine unit with an omphalocele. Fetal macrosomia, organomegaly, and polyhydramnios but no macroglossia were detected and BWS was suspected. Genetic testing for BWS did not confirm the suspected diagnosis as the karyotype was normal. Symptomatic polyhydramnios led to repeated amnioreductions. At 35 + 5 weeks of gestation, a female neonate of 3660 g was delivered with APGAR scores of 6/7/8, after 1/5/10 min, respectively. The abnormal shape of the thorax, facial dysmorphism, need for ventilation, and generalized muscular hypotonia led to the suspicion of Kagami-Ogata syndrome (KOS), which was confirmed by genetic testing. KOS in our patient was caused by a large deletion in the MEG3-region on chromosome 14q32 affecting the maternal allele. In this report, we highlight the notion that when sonographic signs suggestive of BWS such as macrosomia, polyhydramnios, and omphalocele are present and genetic testing does not confirm the suspected diagnosis, KOS should be tested for.


Assuntos
Síndrome de Beckwith-Wiedemann/diagnóstico por imagem , Transtornos Cromossômicos/diagnóstico por imagem , Anormalidades Craniofaciais/diagnóstico por imagem , Deficiências do Desenvolvimento/diagnóstico por imagem , Hérnia Umbilical/diagnóstico por imagem , Poli-Hidrâmnios/diagnóstico por imagem , Dissomia Uniparental/patologia , Adulto , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 14/genética , Anormalidades Craniofaciais/genética , Deficiências do Desenvolvimento/genética , Diagnóstico Diferencial , Feminino , Idade Gestacional , Hérnia Umbilical/genética , Humanos , Recém-Nascido , Poli-Hidrâmnios/genética , Gravidez , Ultrassonografia Pré-Natal , Dissomia Uniparental/genética
20.
Dev Med Child Neurol ; 62(2): 192-200, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31749156

RESUMO

Disruption of epigenetic modifications and the factors that maintain these modifications is rapidly emerging as a cause of developmental disorders. Here we summarize some of the major principles of epigenetics including how epigenetic modifications are: (1) normally reset in the germ line, (2) form an additional layer of interindividual variation, (3) are environmentally sensitive, and (4) change over time in humans. We also briefly discuss the disruption of growth and intellect associated with the Mendelian disorders of the epigenetic machinery and the classical imprinting disorders (such as Beckwith-Wiedemann syndrome, Silver-Russell syndrome, Prader-Willi syndrome, and Angelman syndrome), as well as suggesting some diagnostic considerations for the clinicians taking care of these patients. Finally, we discuss novel therapeutic strategies targeting epigenetic modifications, which may offer a safe alternative to up and coming genome editing strategies for the treatment of genetic diseases. This review provides a starting point for clinicians interested in epigenetics and the role epigenetic disruption plays in human disease. WHAT THIS PAPER ADDS: Clinicians are introduced to four main principles of epigenetics. Clinical features of imprinting disorders and Mendelian disorders of epigenetic machinery are presented.


Assuntos
Transtornos Cromossômicos/genética , Transtornos Cromossômicos/terapia , Epigênese Genética , Animais , Transtornos Cromossômicos/fisiopatologia , Humanos
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