scholarly journals Clinical Performance of an Ultrahigh Resolution Chromosomal Microarray Optimized for Neurodevelopmental Disorders

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Karen S. Ho ◽  
Hope Twede ◽  
Rena Vanzo ◽  
Erin Harward ◽  
Charles H. Hensel ◽  
...  

Copy number variants (CNVs) as detected by chromosomal microarray analysis (CMA) significantly contribute to the etiology of neurodevelopmental disorders, such as developmental delay (DD), intellectual disability (ID), and autism spectrum disorder (ASD). This study summarizes the results of 3.5 years of CMA testing by a CLIA-certified clinical testing laboratory 5487 patients with neurodevelopmental conditions were clinically evaluated for rare copy number variants using a 2.8-million probe custom CMA optimized for the detection of CNVs associated with neurodevelopmental disorders. We report an overall detection rate of 29.4% in our neurodevelopmental cohort, which rises to nearly 33% when cases with DD/ID and/or MCA only are considered. The detection rate for the ASD cohort is also significant, at 25%. Additionally, we find that detection rate and pathogenic yield of CMA vary significantly depending on the primary indications for testing, the age of the individuals tested, and the specialty of the ordering doctor. We also report a significant difference between the detection rate on the ultrahigh resolution optimized array in comparison to the array from which it originated. This increase in detection can significantly contribute to the efficient and effective medical management of neurodevelopmental conditions in the clinic.

2019 ◽  
Vol 5 (6) ◽  
pp. e378 ◽  
Author(s):  
E. Robert Wassman ◽  
Karen S. Ho ◽  
Diana Bertrand ◽  
Kyle W. Davis ◽  
Megan M. Martin ◽  
...  

ObjectiveTo evaluate a new tool to aid interpretation of copy number variants (CNVs) in individuals with neurodevelopmental disabilities.MethodsCritical exon indexing (CEI) was used to identify genes with critical exons (CEGs) from clinically reported CNVs, which may contribute to neurodevelopmental disorders (NDDs). The 742 pathogenic CNVs and 1,363 variants of unknown significance (VUS) identified by chromosomal microarray analysis in 5,487 individuals with NDDs were subjected to CEI to identify CEGs. CEGs identified in a subsequent random series of VUS were evaluated for relevance to CNV interpretation.ResultsCEI identified a total of 2,492 unique CEGs in pathogenic CNVs and 953 in VUS compared with 259 CEGs in 6,965 CNVs from 873 controls. These differences are highly significant (p < 0.00001) whether compared as frequency, average, or normalized by CNV size. Twenty-one percent of VUS CEGs were not represented in Online Mendelian Inheritance in Man, highlighting limitations of existing resources for identifying potentially impactful genes within CNVs. CEGs were highly correlated with other indices and known pathways of relevance. Separately, 136 random VUS reports were reevaluated, and 76% of CEGs had not been commented on. In multiple cases, further investigation yielded additional relevant literature aiding interpretation. As one specific example, we discuss GTF2I as a CEG, which likely alters interpretation of several reported duplication VUS in the Williams-Beuren region.ConclusionsApplication of CEI to CNVs in individuals with NDDs can identify genes of potential clinical relevance, aid laboratories in effectively searching the clinical literature, and support the clinical reporting of poorly annotated VUS.


2020 ◽  
Vol 09 (04) ◽  
pp. 270-278
Author(s):  
Hugo H. Abarca-Barriga ◽  
Milana Trubnykova ◽  
Félix Chavesta-Velásquez ◽  
Claudia Barletta-Carrillo ◽  
Marco Ordoñez-Linares ◽  
...  

AbstractCopy number variation in loss of 3p13 is an infrequently reported entity characterized by hypertelorism, aniridia, microphthalmia, high palate, neurosensorial deafness, camptodactyly, heart malformation, development delay, autism spectrum disorder, seizures, and choanal atresia. The entity is caused probably by haploinsufficiency for FOXP1, UBA3, FAM19A1, and MITF. We report a newborn male with hypotonia, facial dysmorphism, heart malformation, and without clinical diagnosis; nevertheless, the use of appropriate genetic test, such us the chromosomal microarray analysis allowed identification of a copy number variant in loss of 5.5 Mb at chromosome 3 (p13-p14.1), that included 54 genes, encompassing FOXP1 gene. We compare the findings in our Peruvian patient to those of earlier reported patients; furthermore, add new signs for this entity.


2021 ◽  
Author(s):  
Hosneara Akter ◽  
Muhammad Mizanur Rahman ◽  
Shaoli Sarker ◽  
Mohammed Basiruzzaman ◽  
Mazharul Islam ◽  
...  

Abstract Background: Copy number variations (CNVs) play a critical role into the pathogenesis of neurodevelopmental disorders (NDD) among children. In this study, we aim to identify clinically relevant CNVs, genes and their phenotypic characteristics in an ethnically underrepresented homogenous population of Bangladesh. Methods: We have conducted genome-wide chromosomal microarray analysis (CMA) for 212 NDD patients with male to female ratio of 2.2:1.0 to identify rare chromosomal abnormalities (deletion /duplication/ rearrangements). To identify candidate genes within the rare CNVs, multiple gene constraint metrics (i.e. “Critical-Exon Genes (CEGs)”) were applied to the population data. Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) was followed in a subset of 95 NDD patients to assess the severity of autism and all statistical tests were performed using R package. Results: In our cohort, the head circumference of males are significantly greater than females (p=0.0002). Of all samples assayed, 12.26% (26/212) and 47.17% (100/212) patients carried pathogenic and variant of uncertain significance (VOUS) CNVs, respectively. 2.83% (6/212) pathogenic CNVs are located at the subtelomeric regions. Further burden test identified females are significant carriers of pathogenic CNVs in comparison to males (OR=4.2; p=0.0007). ADOS-2 subset show severe social communication deficit (p=0.014) and overall ASD symptoms severity (p=0.026) among the patients carrying duplication CNV compared to the CNV negative group. Candidate gene analysis identified 153 unique CEGs in pathogenic CNVs and 31 in VOUS. Of the unique genes, 18 genes were found to be in smaller (<1 MB) focal CNVs and identified PSMC3 gene as a potential candidate gene for Autism Spectrum Disorder (ASD). Moreover, we hypothesized that KMT2B gene duplication might be associated with intellectual disability. Conclusion: Our results show the utility of CMA for precise genetic diagnosis and its integration into the diagnosis therapeutics and management of NDD patients.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ben Pode-Shakked ◽  
Ortal Barel ◽  
Amihood Singer ◽  
Miriam Regev ◽  
Hana Poran ◽  
...  

AbstractExome sequencing (ES) is an important diagnostic tool for individuals with neurodevelopmental disorders (NDD) and/or multiple congenital anomalies (MCA). However, the cost of ES limits the test's accessibility for many patients. We evaluated the yield of publicly funded clinical ES, performed at a tertiary center in Israel, over a 3-year period (2018–2020). Probands presented with (1) moderate-to-profound global developmental delay (GDD)/intellectual disability (ID); or (2) mild GDD/ID with epilepsy or congenital anomaly; and/or (3) MCA. Subjects with normal chromosomal microarray analysis who met inclusion criteria were included, totaling 280 consecutive cases. Trio ES (proband and parents) was the default option. In 252 cases (90.0%), indication of NDD was noted. Most probands were males (62.9%), and their mean age at ES submission was 9.3 years (range 1 month to 51 years). Molecular diagnosis was reached in 109 probands (38.9%), mainly due to de novo variants (91/109, 83.5%). Disease-causing variants were identified in 92 genes, 15 of which were implicated in more than a single case. Male sex, families with multiple-affected members and premature birth were significantly associated with lower ES yield (p < 0.05). Other factors, including MCA and coexistence of epilepsy, autism spectrum disorder, microcephaly or abnormal brain magnetic resonance imaging findings, were not associated with the yield. To conclude, our findings support the utility of clinical ES in a real-world setting, as part of a publicly funded genetic workup for individuals with GDD/ID and/or MCA.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Mingjing Xia ◽  
Xinhong Yang ◽  
Jing Fu ◽  
Zhenjuan Teng ◽  
Yan Lv ◽  
...  

Abstract Background To explore the application value of chromosomal microarray analysis (CMA) in prenatal diagnosis. Methods The results of chromosome karyotype analysis and CMA of 477 cases undergoing amniocentesis were analyzed. The results of the no ultrasound abnormality group and the ultrasound abnormality group were compared separately. Within the ultrasound abnormality group, the results of the ultrasound structural malformation group, the ultrasound soft index abnormality group, and other ultrasound abnormality (including abnormal amniotic fluid volume and fetal growth restriction) groups were compared. Results Abnormal chromosome and CMA results were found in a total of 71 cases (15.88%, 71/447), which can be broken down into a total of 23 karyotype abnormalities (5.15%, 23/447), consisting of 18 cases of aneuploidy (4.03%, 18/447), 2 cases of unbalanced chromosome rearrangements (0.44%, 2/447), and 3 cases of chimerism (0.67%, 3/447); 17 cases with detection of pathogenic copy number variations (pCNVs) (3.80%, 17/447); and 31 cases of detection of clinical variants of unknown significance (VOUS) (6.93%, 31/447). CMA detected 3.8% more genetic abnormalities than karyotype analysis (in addition to the abnormalities detected simultaneously by karyotype analysis). Between the no ultrasound abnormality group and the ultrasound abnormality group, there was an extremely significant difference in the detection rate of an abnormal chromosomal karyotype (P < 0.01) and of VOUS (P < 0.01), but there was no significant difference in the detection rate of pCNV (P > 0.05). Comparing the ultrasound structural malformation group, the ultrasound soft index abnormality group, and the other ultrasound abnormality group, there were no significant differences in the detection rate of abnormal chromosomal karyotypes (P > 0.05), pCNV (P > 0.05) or VOUS (P > 0.05). Conclusions The detection rate of chromosomal karyotype abnormalities in prenatal diagnosis in cases with no ultrasound abnormalities was higher. For cases with fetal ultrasound structural abnormalities, when compared with traditional karyotype analysis, CMA can improve the detection rate of fetal genetic abnormalities. However, the no ultrasound abnormality group also had a high VOUS abnormality detection rate, so it is necessary to strictly define the CMA indications.


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