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BACKGROUND: Distal Xq28 duplication, or int22h1/int22h2-mediated Xq28 duplication syndrome, leads to cognitive impairment, neurobehavioral issues, and facial dysmorphisms. Existing literature has limited information on clinical traits and penetrance. METHODS: We identified cases of distal Xq28 duplication (chrX: 154,126,575-154,709,680, GRCh37/hg19) through a review of clinical records and microarray reports from five centers, encompassing both postnatal and prenatal cases, with no prior family knowledge of the duplication. RESULTS: Our search found 47 cases across 26 families, with duplications ranging from 208 to 935 Kb. In total, 8 out of 26 index cases featured a 200-300 kb partial duplication, mainly from Armenian/Caucasian Jewish backgrounds. Most prenatal cases showed no major fetal ultrasound malformations. Of cases with known inheritance mode (15 out of 26), maternal inheritance was more common (80%). The study identified seven male carriers of the duplication from six unrelated families, indicating partial penetrance in males. CONCLUSION: Our study provides key insights into distal Xq28 duplication. Most prenatal tests showed no major fetal ultrasound issues. Maternal inheritance was common, with unaffected mothers. In the postnatal group, a balanced gender distribution was observed. Among male family members, two fathers had ADHD, one was healthy, and one brother had mild symptoms, indicating partial penetrance in males.
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Duplicação Cromossômica , Cromossomos Humanos X , Penetrância , Humanos , Masculino , Feminino , Cromossomos Humanos X/genética , Duplicação Cromossômica/genética , Criança , Adulto , Pré-Escolar , Adolescente , Linhagem , Lactente , FenótipoRESUMO
Long contiguous stretches of homozygosity or regions of homozygosity (ROH) are frequently detected via microarray and sequencing technologies. However, consensus on the establishment of specific size cutoffs for reporting ROH remains elusive. This study aims to assess the Total ROH Percentages (TRPS) and size of ROH segments across different ethnic origins, exploring potential disparities and proposing tailored diagnostic thresholds. This retrospective study included 13,035 microarray analyses conducted between 2017 to 2023. ROH segments on autosomal chromosomes were retrieved, and samples lacking ROH segments were excluded. The cohort was categorized based on reported ethnic origins, and TRPS and ROH segment size were analyzed for each origin. Distinct TRPS values were noted among different ethnic groups, ranging from median 0.36% in Ethiopian Jewish cohort and up to 6.42% in the Bedouin population. Wide range of 99th percentiles of ROH segment size for various origins was noted, ranging from 10.6 to 51.5 Mb. A significant correlation between ROH segment sizes and TRPS was noted in each origin. Statistically significant differences in ROH segment sizes were noted between the Jewish and the Israeli Arab/Druze origins in TRPS from 1% to 9.99%, whereas extremities of low (0.11%-0.99%) and high (over 10%) TRPS yielded no significant differences. In conclusion, as fixed absolute size thresholds may overlook pathogenic segments in certain populations while generating excessive reports in others, tailored approaches to define ROH reporting thresholds can be considered to facilitate the accuracy and clinical relevance of genomic analyses.
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OBJECTIVE: This study aimed to determine the diagnostic yield of chromosomal microarray analysis (CMA) performed in cases of fetal abnormalities detected during the third trimester of pregnancy. STUDY DESIGN: A retrospective review of medical records was conducted for women who underwent amniocentesis at or beyond 28 weeks of gestation between January 2017 and February 2023. CMA results of pregnancies with abnormal sonographic findings not detected before 28 weeks were included. RESULTS: A total of 482 fetuses met the inclusion criteria. The average maternal age was 31.3 years, and the average gestational age at amniocentesis was 32.3 weeks. The overall diagnostic yield of CMA was 6.2% (30 clinically significant copy number variations [CNVs]). The yield was 16.4% in cases with two or more fetal malformations, while cases with a single anomaly revealed a diagnostic yield of 7.3%. Cases presenting isolated polyhydramnios or isolated fetal growth restriction had a lower yield of 9.3 and 5.4%, respectively. Of the 30 clinically significant cases, 19 (or 63.4%) exhibited recurrent CNVs. The remaining 11 cases (or 36.6%) presented unique CNVs. The theoretical yield of Noninvasive Prenatal Testing (NIPT) in our cohort is 2% for aneuploidy, which implies that it could potentially miss up to 70% of the significant findings that could be identified by CMA. In 80% of the fetuses (or 24 out of 30) with clinically significant CNVs, the structural abnormalities detected on fetal ultrasound examinations corresponded with the CMA results. CONCLUSION: The 6.2% detection rate of significant CNVs in late-onset fetal anomalies confirms the value of CMA in third-trimester amniocentesis. The findings underscore the necessity of CMA for detecting CNVs potentially overlooked by NIPT and emphasize the importance of thorough genetic counseling. KEY POINTS: · CMA yields 6.2% for third-trimester anomalies.. · NIPT may miss 70% of CMA findings.. · Ultrasound matched 80% of CMA results..
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INTRODUCTION: Microcephaly, characterized by abnormal head growth, can often serve as an initial indicator of congenital, genetic, or acquired disorders. In this study, we sought to evaluate the effectiveness of chromosomal microarray (CMA) testing in detecting abnormalities in both prenatal and postnatal cases of microcephaly. MATERIALS AND METHODS: CMA Testing: We conducted CMA testing on 87 prenatally-detected microcephaly cases and 742 postnatal cases at a single laboratory. We evaluated the CMA yield in relation to specific clinical characteristics. RESULTS: In prenatal cases, pathogenic and likely pathogenic (LP) results were identified in 4.6% of cases, a significantly higher rate compared to low-risk pregnancies. The male-to-female ratio in this cohort was 3, and the CMA yield was not influenced by gender or other clinical parameters. For postnatal cases, the CMA yield was 15.0%, with a significantly higher detection rate associated with dysmorphism, hypotonia, epilepsy, congenital heart malformations (CHM), learning disabilities (LD), and a history of Fetal growth restriction (FGR). No specific recurrent copy number variations (CNVs) were observed, and the rate of variants of unknown significance was 3.9%. CONCLUSIONS: The yield of CMA testing in prenatal microcephaly is lower than in postnatal cases (4.6% vs. 15%). The presence of microcephaly, combined with dysmorphism, hypotonia, epilepsy, CHD, LD, and FGR, significantly increases the likelihood of an abnormal CMA result.
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Proximal 1q21 microduplication is an incomplete penetrance and variable expressivity syndrome. This study reports 28 new cases and summarizes data on phenotype, gender, and parental origin. Data on isolated proximal 1q21.1 microduplications (g. chr1:145,394,956-145,762,959 GRCh37/hg19) was retrieved in postnatal and prenatal "clinical cases" group, and prenatal "control group." The "clinical cases" cases included cases where chromosomal microarray (CMA) was performed due to congenital anomalies, autism spectrum disorder, seizures, and developmental delay/intellectual disability. The "control group" cases consisted of fetal CMA performed upon parental request despite normal nuchal translucency and anatomical second trimester fetal scans. We analyzed a local database of 27,990 cases and another cohort of 80,000 cases (including both indicated and non-indicated cases) for population frequency analysis. A total of 62 heterozygous cases were found, including 28 index cases and 34 family members. Among the index cases, 13 (9 males, 4 females) were identified in the "clinical cases" group, of which 10 had developmental abnormalities. Parental origin was tested in 9/13 cases, and all were found to be maternally inherited. In the "control group," which comprised non-affected cases, of 15 cases (10 males, 5 females), only 5/11 were maternally inherited. Four cases with clinical follow-up showed no reported neurodevelopmental abnormalities. No de-novo cases were detected, and the population frequency in both cohorts was 1:1000. Proximal 1q21.1 microduplication is a recurrent copy number variant, associated with neurodevelopmental abnormalities. It has a greater impact on males inheriting it from their mothers than females from their fathers.
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Transtorno do Espectro Autista , Deficiência Intelectual , Masculino , Gravidez , Feminino , Humanos , Transtorno do Espectro Autista/genética , Deficiência Intelectual/genética , Fenótipo , Cromossomos , Análise em MicrossériesRESUMO
BACKGROUND: Chromosomal microarray analysis detects a clinically significant amount of copy number variants in approximately 1% of low-risk pregnancies. As the constantly growing use of noninvasive prenatal screening has facilitated the detection of chromosomal aberrations, defining the rate of abnormal chromosomal microarray analysis findings following normal noninvasive prenatal screening is of importance for making informed decisions regarding prenatal testing and screening options. OBJECTIVE: To calculate the residual risk for clinically significant copy number variants following theoretically normal noninvasive prenatal screening. STUDY DESIGN: The chromosomal microarray results of all pregnancies undergoing amniocentesis between the years 2013 and 2021 in a large hospital-based laboratory were collected. Pregnancies with sonographic anomalies, abnormal maternal serum screening, or multiple fetuses were excluded. Clinically significant (pathogenic and likely pathogenic) copy number variants were divided into the following: 3-noninvasive prenatal screening-detectable (trisomies 13, 18, and 21), 5- noninvasive prenatal screening-detectable (including sex chromosome aberrations), 5-noninvasive prenatal screening and common microdeletion-detectable (including 1p36.3-1p36.2, 4p16.3-4p16.2, 5p15.3-5p15.1, 15q11.2-15q13.1, and 22q11.2 deletions), and genome-wide noninvasive prenatal screening-detectable (including variants >7 Mb). The theoretical residual risk for clinically significant copy number variants was calculated following the exclusion of noninvasive prenatal screening-detectable findings. RESULTS: Of the 7235 pregnancies, clinically significant copy number variants were demonstrated in 87 cases (1.2%). The residual risk following theoretically normal noninvasive prenatal screening was 1.07% (1/94) for 3-noninvasive prenatal screening, 0.78% (1/129) for 5- noninvasive prenatal screening, 0.74% (1/136) for 5- noninvasive prenatal screening including common microdeletions, and 0.68% (1/147) for genome-wide noninvasive prenatal screening. In the subgroup of 4048 pregnancies with advanced maternal age, the residual risk for clinically significant copy number variants following theoretically normal noninvasive prenatal screening ranged from 1.36% (1/73) for 3- noninvasive prenatal screening to 0.82% (1/122) for genome-wide noninvasive prenatal screening. In 3187 pregnancies of women <35 years, this residual risk ranged from 0.69% (1/145) for 3- noninvasive prenatal screening to 0.5% (1/199) for genome-wide noninvasive prenatal screening. CONCLUSION: The residual risk of clinically significant copy number variants in pregnancies without structural sonographic anomalies is appreciable and depends on the noninvasive prenatal screening extent and maternal age. This knowledge is important for the patients, obstetricians, and genetic counselors to facilitate informed decisions regarding prenatal testing and screening options.
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Teste Pré-Natal não Invasivo , Amniocentese , Aberrações Cromossômicas , Variações do Número de Cópias de DNA , Feminino , Humanos , Análise em Microsséries , Gravidez , Diagnóstico Pré-Natal/métodos , Síndrome da Trissomia do Cromossomo 13/diagnósticoRESUMO
PURPOSE: This study aimed to evaluate the prevalence of clinically significant (pathogenic and likely pathogenic) variants detected by chromosomal microarray (CMA) tests performed for prenatally and postnatally detected congenital heart defects. METHODS: A retrospective evaluation of CMA analyses over a period of four years in a single tertiary medical center was performed. Detection rate of clinically significant variants was calculated in the whole cohort, prenatal vs. postnatal cases, and isolated vs. non-isolated CHD. This rate was compared to previously published control cohorts, and to a theoretical detection rate of noninvasive prenatal testing (NIPS; 5 chromosomes). RESULTS: Of the 885 cases of CHD, 111 (12.5%) clinically significant variants were detected, with no significant difference between the 498 prenatal and the 387 postnatal cases (10.8% vs. 14.7%, p = 0.08). In both groups, the detection rate was significantly higher for non-isolated vs. isolated CHD (76/339 = 22.4% vs. 35/546 = 6.4%, respectively, p < 0.05). The detection rate was higher than the background risk in both groups, including cases of postnatal isolated CHD. 44% of abnormal findings in the prenatal setting would be detectable by NIPS. CONCLUSION: CMA should be performed for both prenatally and postnatally detected CHD, including postnatal cases of isolated CHD, while NIPS can be considered in specific scenarios.
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Cardiopatias Congênitas , Diagnóstico Pré-Natal , Feminino , Humanos , Gravidez , Aberrações Cromossômicas , Cromossomos , Cardiopatias Congênitas/epidemiologia , Cardiopatias Congênitas/genética , Análise em Microsséries , Estudos Retrospectivos , Ultrassonografia Pré-NatalRESUMO
The population of Israel is ethnically diverse, and individuals from different ethnic groups share specific genetic variations. These variations, which have been passed on from common ancestors, are usually reported in public databases as rare variants. Here, we aimed to identify ethnicity-based benign copy number variants (CNVs) and generate the first Israeli CNV database. We applied a data-mining approach to the results of 10,193 chromosomal microarray tests, of which 2150 tests were from individuals of 13 common ethnic backgrounds (n ≥ 10). We found 165 CNV regions (> 50 kbp) that are unique to specific ethnic groups (uCNVRs). The frequency of more than 19% of these uCNVRs is between 1 and 20% of the common ethnic origin, while their frequency in the overall cohort is between 0.5 and 1.6%. Of these 165 uCNVRs, 98 are reported as variants of unknown significance or as not available in dbVar; we postulate that these uCNVRs should be annotated as either "likely benign" or "benign". The ethnic-specific CNVs extracted in this study will allow geneticists to distinguish between relevant pathogenic genomic aberrations and benign ethnicity-related variations, thus preventing variant misinterpretation that may lead to unnecessary pregnancy terminations.
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Variações do Número de Cópias de DNA , Judeus/genética , Feminino , Humanos , Israel , MasculinoRESUMO
Diagnosis of rare copy number variants (CNVs) with scarce literature evidence poses a major challenge for interpretation of the clinical significance of chromosomal microarray analysis (CMA) results, especially in the prenatal setting. Bioinformatic tools can be used to assist in this issue; however, this prediction can be imprecise. Our objective was to describe the phenotype of the rare copy number losses encompassing the 8q24.13-q24.3 locus, and to find common features in terms of genomic coordinates, gene content, and clinical phenotypic characteristics. Appropriate cases were retrieved using local databases of two largest Israeli centers performing CMA analysis. In addition, literature and public databases search was performed. Local database search yielded seven new patients with del (8)(q24.13q24.3) (one of these with an additional copy number variant). Literature and public databases search yielded eight additional patients. The cases showed high phenotypic variability, ranging from asymptomatic adults and fetuses with normal ultrasound to patients with autism/developmental delay (6/11 postnatal cases, 54.5%). No clear association was noted between the specific disease-causing/high-pLI gene content of the described del (8)(q24.13q24.3) to neurodevelopmental disorders, except for a possibly relevant locus encompassing the KCNQ3 gene. We present the challenges in classification of rare variants with limited clinical information. In such cases, genotype-phenotype correlation must be assessed with extra-caution and possibly using additional methods to assist the classification, especially in the prenatal setting.
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Deleção Cromossômica , Cromossomos Humanos Par 8/genética , Deficiências do Desenvolvimento/genética , Transtornos do Neurodesenvolvimento/genética , Adulto , Criança , Variações do Número de Cópias de DNA/genética , Deficiências do Desenvolvimento/complicações , Deficiências do Desenvolvimento/patologia , Feminino , Estudos de Associação Genética , Humanos , Deficiência Intelectual/complicações , Deficiência Intelectual/patologia , Masculino , Análise em Microsséries/economia , Transtornos do Neurodesenvolvimento/complicações , Transtornos do Neurodesenvolvimento/patologia , Fenótipo , GravidezRESUMO
PURPOSE: To evaluate the diagnostic yield of chromosomal microarray (CMA) in pregnancies with normal ultrasound. METHODS: This retrospective cohort analysis included all pregnancies with normal ultrasound undergoing CMA testing between the years 2010 and 2016. We calculated the rate of detection of clinically significant CMA findings in the whole cohort and according to various indications. RESULTS: Of 5541 CMA analyses, clinically significant findings were yielded in 78 cases (1.4%). Of these, 31 (39.7%) variants could have theoretically been detected by karyotyping (e.g., sized above 10 Mb), and 28 (35.9%) by noninvasive prenatal screening aimed at five common aneuploidies. Of the 47 submicroscopic findings detectable by CMA only, the majority (37 cases, 78.7%) represented known recurrent syndromes. Detection of clinically significant CMA findings in women with no indication for invasive testing was 0.76% (21/2752), which was significantly lower compared with 1.8% in advanced maternal age group (41/2336), 2.8% in abnormal biochemical serum screening (6/211), and 4.1% (10/242) in fetuses with sonographic soft markers. CONCLUSION: Clinically significant CMA aberrations are detected in 1 of 71 pregnancies with normal ultrasound, and in 1 of 131 women with no indication for invasive testing. Thus, CMA might be recommended a first-tier test in pregnancies with normal ultrasound.
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Transtornos Cromossômicos/diagnóstico , Diagnóstico Pré-Natal/métodos , Aneuploidia , Aberrações Cromossômicas/embriologia , Estudos de Coortes , Feminino , Testes Genéticos/métodos , Humanos , Cariotipagem/métodos , Análise em Microsséries/métodos , Gravidez , Estudos Retrospectivos , Ultrassonografia Pré-Natal/métodosRESUMO
PurposeTo compare the frequency of copy-number variants (CNVs) of variable penetrance in low-risk and high-risk prenatal samples and postnatal samples.MethodsTwo cohorts were categorized according to chromosomal microarray analysis (CMA) indication: group I, low-risk prenatal-women with uneventful pregnancy (control group); group II, high-risk prenatal-women whose fetuses had congenital malformations; and group III, postnatal-individuals with unexplained developmental delay/intellectual disability, autism spectrum disorders, or multiple congenital anomalies. CNVs were categorized based on clinical penetrance: (i) high (>40%), (ii) moderate (10-40%), and (iii) low (<10%).ResultsFrom 2013 to 2016, 21,594 CMAs were performed. The frequency of high-penetrance CNVs was 0.1% (21/15,215) in group I, 0.9% (26/2,791) in group II, and 2.6% (92/3,588) in group III. Moderate-penetrance CNV frequency was 0.3% (47/15,215), 0.6% (19/2,791), and 1.2% (46/3,588), respectively. These differences were statistically significant. The frequency of low-penetrance CNVs was not significantly different among groups: 0.6% (85/15,215), 0.9% (25/2,791), and 1.0% (35/3,588), respectively.ConclusionHigh-penetrance CNVs might be a major factor in the overall heritability of developmental, intellectual, and structural anomalies. Low-penetrance CNV alone does not seem to contribute to these anomalies. These data may assist pre- and posttest CMA counseling.
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Estudos de Associação Genética , Heterogeneidade Genética , Genótipo , Fenótipo , Aberrações Cromossômicas , Hibridização Genômica Comparativa , Variações do Número de Cópias de DNA , Feminino , Aconselhamento Genético , Humanos , Recém-Nascido , Masculino , Triagem Neonatal , Penetrância , Polimorfismo de Nucleotídeo Único , Diagnóstico Pré-Natal , SexismoRESUMO
OBJECTIVE: To determine the rate of chromosomal cytogenetic abnormalities in fetuses with late onset abnormal sonographic findings. DESIGN: Retrospective cohort of women who underwent amniocentesis at or beyond 23 weeks of gestation, for fetal karyotype and chromosomal microarray analysis, indicated due to late onset abnormal sonographic findings. RESULTS: All 103 fetuses had a normal karyotype. Ninety-five women also had chromosomal microarray analysis (CMA) performed. The detection rate of abnormal CMA (5/95, 5.3%) was similar to that of women who underwent amniocentesis due to abnormal early onset ultrasound findings detected at routine prenatal screening tests during the first or early second trimester (7.3%, P=0.46) and significantly higher than that for women who underwent amniocentesis and CMA upon request, without a medical indication for CMA (0.99%, P<0.0001). CONCLUSIONS: Late onset sonographic findings are an indication for amniocentesis, and if performed, CMA should be applied to evaluate fetuses with late onset abnormal sonographic findings.
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Aberrações Cromossômicas/estatística & dados numéricos , Transtornos Cromossômicos , Análise Citogenética , Adulto , Amniocentese/métodos , Aneuploidia , Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/epidemiologia , Estudos de Coortes , Análise Citogenética/métodos , Análise Citogenética/estatística & dados numéricos , Feminino , Humanos , Israel/epidemiologia , Gravidez , Terceiro Trimestre da Gravidez , Diagnóstico Pré-Natal/métodos , Estudos Retrospectivos , Ultrassonografia Pré-Natal/métodosRESUMO
BACKGROUND: The rate of clinically significant copy number variants in chromosomal microarray analysis in low-risk pregnancies is approximately 1%. However, these results include copy number variants with low and variable penetrance, although some patients might be interested only in the detection of high-penetrant variants. OBJECTIVE: This study aimed to calculate the prevalence of high-penetrant copy number variants in a large cohort of low-risk pregnancies. STUDY DESIGN: This retrospective study was performed using microarray results of pregnancies with normal ultrasound and maternal serum screening. All clinically significant (pathogenic and likely pathogenic) copy number variants were recorded. Of these, only high-penetrant findings were selected. Findings with low and medium penetrance and copy number variants with unknown clinical penetrance, including uniparental disomy of segments not related to known imprinted syndromes, mosaic aneuploidy of <50%, and segmental mosaicism, were excluded. The calculation was performed for the overall cohort, for women aged >35 years and women aged <35 years, and after omission of noninvasive prenatal screening theoretically detectable findings (trisomies 13, 18, and 21). RESULTS: Clinically significant copy number variants were detected in 118 of 7734 cases (1.50% or 1:65), and high-penetrant copy number variants were detected in 33 of 7734 cases (0.43% or 1:234). In women aged ≥35 years, the rates of high-penetrant copy number variants were 29 of 5734 cases (0.51% or 1:198) and 4 of 2000 cases (0.20% or 1:500) in women aged <35 years (P=.0747). Following the omission of 12 theoretically noninvasive prenatal screening-detectable findings, the rates of high-penetrant copy number variants declined to 21 of 7722 cases (0.27% or 1:368) in the whole cohort-18 of 5723 cases (0.31% or 1:318) in woman aged ≥35 years and 3 of 1999 cases (0.15% or 1:666) in younger women (P=.319). CONCLUSION: The risk of high-penetrant copy number variants in low-risk pregnancies exceeds the risk of miscarriage after invasive testing, even after normal noninvasive prenatal screening results. These results are of importance to genetic counselors and obstetricians, to facilitate maternal informed decision-making when considering invasive prenatal testing in low-risk pregnancies.
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Variações do Número de Cópias de DNA , Diagnóstico Pré-Natal , Gravidez , Humanos , Feminino , Diagnóstico Pré-Natal/métodos , Estudos Retrospectivos , Prevalência , Aberrações CromossômicasRESUMO
OBJECTIVE: To examine the effect of maternal age on the rate of clinically significant chromosomal microarray analysis results in pregnancies with abnormal maternal serum screening and to establish the residual risk for abnormal microarray findings after omitting noninvasive prenatal testing (NIPT)-detectable aberrations in pregnancies with abnormal maternal serum screening. METHODS: This retrospective study included all chromosomal microarray analysis tests performed in pregnancies with abnormal maternal serum screening and normal ultrasonogram results over the years 2013-2021. The rate of clinically significant (pathogenic and likely pathogenic) chromosomal microarray analysis findings was compared with a local control cohort of 7,235 pregnancies with normal maternal serum screening and ultrasonogram results, stratified by maternal age. Calculation of residual risk for clinically significant chromosomal microarray analysis results after normal NIPT was performed by omission of common NIPT-detectable anomalies. Systematic review for studies examining the yield of chromosomal microarray analysis in pregnancies with abnormal maternal serum screening was performed from inception to October 2021, with no time or language restrictions. RESULTS: Of the 559 amniocenteses performed due to abnormal maternal serum screening, 21 (3.8%; 95% CI 2.4-5.7%) clinically significant chromosomal microarray analysis results were found. The residual risk for chromosomal microarray analysis aberrations after theoretically normal NIPT was estimated to be 2.0% (95% CI 1.1-3.6%) (1/50) and was significantly higher for women younger than age 35 years with abnormal maternal serum screening, compared with women with low-risk pregnancies. Systematic review yielded six articles encompassing 4,890 chromosomal microarray analysis results in pregnancies with abnormal maternal serum screening, demonstrating 2.3% residual risk for chromosomal microarray analysis anomalies after theoretically normal NIPT. DISCUSSION: Clinically significant chromosomal microarray analysis findings can be found in 1 of every 50 pregnancies with high-risk maternal serum screening after theoretically normal NIPT, implying that invasive testing and not NIPT should be recommended in such pregnancies. In addition, NIPT use as a first-tier screening modality instead of maternal serum screening would miss pregnancies at increased risk not only for common autosomal trisomies but for additional chromosomal microarray analysis-detectable disorders.
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Transtornos Cromossômicos , Teste Pré-Natal não Invasivo , Adulto , Aberrações Cromossômicas , Transtornos Cromossômicos/diagnóstico , Feminino , Humanos , Análise em Microsséries , Gravidez , Diagnóstico Pré-Natal/métodos , Estudos RetrospectivosRESUMO
INTRODUCTION: Congenital contractural arachnodactyly (CCA) is a rare connective tissue disorder, associated with heterozygous mutations in the FBN2 gene. The objective of this study was to evaluate the prevalence of an intragenic deletion encompassing exons 1-8 of FBN2 gene in Israeli population. MATERIALS AND METHODS: A search for intragenic FBN2 microdeletions was performed in two databases of chromosomal microarray analysis (CMA) - genetic laboratory of a tertiary medical center (the primary cohort) and one of the largest Israeli health maintenance organizations (replication cohort). RESULTS: Overall, 52,879 microarray tests were searched for FBN2 microdeletions. The primary cohort constituted of 18,301 CMA tests, among which 33 intragenic FBN2 microdeletions in unrelated individuals were found (0.18%). Prenatal prevalence of this variant was 0.23% (28/12,604), and specifically in low risk pregnancies - 0.29% (22/7464). Of the 28 cases with known parental origin, 27 (96.4%) were of full or partial Ashkenazi Jewish ethnic background. The approximate allele incidence in the Ashkenazi Jewish origin was 0.4% (18/4961). Combined with the 34,578 CMA tests in the replication cohort, the overall frequency of FBN2 microdeletions was 0.24% (125/52,879). None of the pre- or postnatal cases had any clinical manifestations of CCA. DISCUSSION: Intragenic FBN2 microdeletions are found in one of every 420 CMA analyses in Israeli population, and in particular one of every 340 low-risk pregnancies. Due to high allele incidence in Ashkenazi Jewish population (1:275), we suggest that FBN2 gene deletion detected by CMA among Ashkenazi Jews should be interpreted as benign copy number variant.
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Aracnodactilia/genética , Contratura/genética , Fibrilina-2/genética , Alelos , Estudos de Coortes , Contratura/congênito , Éxons , Feminino , Fibrilina-2/sangue , Testes Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Israel , Judeus , Masculino , Análise em Microsséries , Teste Pré-Natal não Invasivo , Gravidez , Deleção de SequênciaRESUMO
Copy number variations of the 15q11.2 region at breakpoints 1-2 (BP1-BP2) have been associated with variable phenotypes and low penetrance. Detection of such variations in the prenatal setting can result in significant parental anxiety. The clinical significance of pre- and postnatally detected 15q11.2 BP1-BP2 deletions and duplications was assessed. Of 11,004 chromosomal microarray tests performed in a single referral lab (7596 prenatal, 3408 postnatal), deletions were detected in 66 cases: 39 in prenatal tests (0.51%) and 27 in postnatal tests (0.79%). Duplications were detected in 94 cases: 62 prenatal tests (0.82%) and 32 postnatal tests (0.94%). The prevalence of deletions and duplications among clinically indicated prenatal tests (0.57% and 0.9%, respectively) did not differ significantly in comparison to unindicated tests (0.49% and 0.78%, respectively). The prevalence of deletions and duplications among postnatal tests performed for clinical indications was similar to the prevalence in healthy individuals (0.73% and 1% vs. 0.98% and 0.74%, respectively). The calculated penetrance of deletions and duplications over the background risk was 2.18% and 1.16%, respectively. We conclude that the pathogenicity of 15q11.2 BP1-BP2 deletions and duplications is low. Opting out the report of these copy number variations to both clinicians and couples should be considered.
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BACKGROUND: Microdeletions of various sizes in the 2p16.1-p15 chromosomal region have been grouped together under the 2p16.1-p15 microdeletion syndrome. Children with this syndrome generally share certain features including microcephaly, developmental delay, facial dysmorphism, urogenital and skeletal abnormalities. We present a child with a de-novo interstitial 1665 kb duplication of 2p16.1-p15. METHODS AND RESULTS: Clinical features of this child are distinct from those of children with the 2p16.1-p15 microdeletion syndrome, specifically the head circumference which is within the normal range and mild intellectual disability with absence of autistic behaviors. Microduplications many times bear milder clinical phenotypes in comparison with corresponding microdeletion syndromes. Indeed, as compared to the microdeletion syndrome patients, the 2p16.1-p15 microduplication seems to have a milder cognitive effect and no effect on other body systems. Limited information available in genetic databases about cases with overlapping duplications indicates that they all have abnormal developmental phenotypes. CONCLUSION: The involvement of genes in this location including BCL11A, USP34 and PEX13, affecting fundamental developmental processes both within and outside the nervous system may explain the clinical features of the individual described in this report.
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Cromossomos Humanos Par 2/genética , Duplicação Gênica/genética , Transtorno Autístico/etiologia , Transtorno Autístico/psicologia , Proteínas de Transporte/genética , Criança , Pré-Escolar , Mapeamento Cromossômico , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/psicologia , Deficiências do Desenvolvimento/genética , Cabeça/anatomia & histologia , Humanos , Recém-Nascido , Deficiência Intelectual/etiologia , Deficiência Intelectual/genética , Masculino , Proteínas de Membrana/genética , Análise em Microsséries , Microcefalia/genética , Proteínas Nucleares/genética , Proteínas Repressoras , Síndrome , Proteases Específicas de Ubiquitina/genéticaRESUMO
In this study we examined the effects of proteasome inhibitors on cell apoptosis in TRAIL-resistant glioma cells and glioma stem cells (GSCs). Treatment with proteasome inhibitors and TRAIL induced apoptosis in all the resistant glioma cells and GSCs, but not in astrocytes and neural progenitor cells. Since PKCε has been implicated in the resistance of glioma cells to TRAIL, we examined its role in TRAIL and proteasome inhibitor-induced apoptosis. We found that TRAIL did not induce significant changes in the expression of PKCε, whereas a partial decrease in PKCε expression was obtained by proteasome inhibitors. A combined treatment of TRAIL and proteasome inhibitors induced accumulation of the catalytic fragment of PKCε and significantly and selectively decreased its protein and mRNA levels in the cancer but not in normal cells. Overexpression of PKCε partially inhibited the apoptotic effect of the proteasome inhibitors and TRAIL, and the caspase-resistant PKCεD383A mutant exerted a stronger inhibitory effect. Silencing of PKCε induced cell apoptosis in both glioma cells and GSCs, further supporting its role in cell survival. TRAIL and the proteasome inhibitors decreased the expression of AKT and XIAP in a PKCε-dependent manner and overexpression of these proteins abolished the apoptotic effect of this treatment. Moreover, silencing of XIAP sensitized glioma cells to TRAIL. Our results indicate that proteasome inhibitors sensitize glioma cells and GSCs to TRAIL by decreasing the expression of PKCε, AKT and XIAP. Combining proteasome inhibitors with TRAIL may be useful therapeutically in the treatment of gliomas and the eradication of GSCs.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Glioma/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Inibidores de Proteases/farmacologia , Inibidores de Proteassoma , Proteína Quinase C-épsilon/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Apoptose , Astrócitos/efeitos dos fármacos , Ácidos Borônicos/farmacologia , Bortezomib , Linhagem Celular Tumoral , Regulação para Baixo , Glioma/enzimologia , Humanos , Leupeptinas/farmacologia , Mutagênese Sítio-Dirigida , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteína Quinase C-épsilon/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirazinas/farmacologia , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismoRESUMO
The mechanism underlying the important role of protein kinase Cdelta (PKCdelta) in the apoptotic effect of etoposide in glioma cells is incompletely understood. Here, we examined the role of PKCdelta in the activation of Erk1/2 by etoposide. We found that etoposide induced persistent activation of Erk1/2 and nuclear translocation of phospho-Erk1/2. MEK1 inhibitors decreased the apoptotic effect of etoposide, whereas inhibitors of p38 and JNK did not. The activation of Erk1/2 by etoposide was downstream of PKCdelta since the phosphorylation of Erk1/2 was inhibited by a PKCdelta-KD mutant and PKCdelta small interfering RNA. We recently reported that phosphorylation of PKCdelta on tyrosines 64 and 187 was essential for the apoptotic effect of etoposide. Using PKCdeltatyrosine mutants, we found that the phosphorylation of PKCdeltaon these tyrosine residues, but not on tyrosine 155, was also essential for the activation of Erk1/2 by etoposide. In contrast, nuclear translocation of PKCdelta was independent of its tyrosine phosphorylation and not necessary for the phosphorylation of Erk1/2. Etoposide induced down-regulation of kinase phosphatase-1 (MKP-1), which correlated with persistent phosphorylation of Erk1/2 and was dependent on the tyrosine phosphorylation of PKCdelta. Moreover, silencing of MKP-1 increased the phosphorylation of Erk1/2 and the apoptotic effect of etoposide. Etoposide induced polyubiquitylation and degradation of MKP-1 that was dependent on PKCdelta and on its tyrosine phosphorylation. These results indicate that distinct phosphorylation of PKCdeltaon tyrosines 64 and 187 specifically activates the Erk1/2 pathway by the down-regulation of MKP-1, resulting in the persistent phosphorylation of Erk1/2 and cell apoptosis.