scholarly journals MLPA is a practical and complementary alternative to CMA for diagnostic testing in patients with autism spectrum disorders and identifying new candidate CNVs associated with autism

PeerJ ◽  
2019 ◽  
Vol 6 ◽  
pp. e6183 ◽  
Author(s):  
Pavlina Capkova ◽  
Josef Srovnal ◽  
Zuzana Capkova ◽  
Katerina Staffova ◽  
Vera Becvarova ◽  
...  
Keyword(s):  
Clinical Significance ◽  
Diagnostic Testing ◽  
Copy Number Variants ◽  
Ring Chromosome ◽  
Autism Spectrum ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Rare Cnvs ◽  
Pathogenic Variants ◽  
Dependent Probe

Background Autism spectrum disorder (ASD) is a complex heterogeneous developmental disease with a significant genetic background that is frequently caused by rare copy number variants (CNVs). Microarray-based whole-genome approaches for CNV detection are widely accepted. However, the clinical significance of most CNV is poorly understood, so results obtained using such methods are sometimes ambiguous. We therefore evaluated a targeted approach based on multiplex ligation-dependent probe amplification (MLPA) using selected probemixes to detect clinically relevant variants for diagnostic testing of ASD patients. We compare the reliability and efficiency of this test to those of chromosomal microarray analysis (CMA) and other tests available to our laboratory. In addition, we identify new candidate genes for ASD identified in a cohort of ASD-diagnosed patients. Method We describe the use of MLPA, CMA, and karyotyping to detect CNV in 92 ASD patients and evaluate their clinical significance. Result Pathogenic and likely pathogenic mutations were identified by CMA in eight (8.07% of the studied cohort) and 12 (13.04%) ASD patients, respectively, and in eight (8.07%) and four (4.35%) patients, respectively, by MLPA. The detected mutations include the 22q13.3 deletion, which was attributed to ring chromosome 22 formation based on karyotyping. CMA revealed a total of 91 rare CNV in 55 patients: eight pathogenic, 15 designated variants of unknown significance (VOUS)—likely pathogenic, 10 VOUS—uncertain, and 58 VOUS—likely benign or benign. MLPA revealed 18 CNV in 18 individuals: eight pathogenic, four designated as VOUS—likely pathogenic, and six designated as VOUS—likely benign/benign. Rare CNVs were detected in 17 (58.62%) out of 29 females and 38 (60.32%) out of 63 males in the cohort. Two genes, DOCK8 and PARK2, were found to be overlapped by CNV designated pathogenic, VOUS—likely pathogenic, or VOUS—uncertain in multiple patients. Moreover, the studied ASD cohort exhibited significant (p < 0.05) enrichment of duplications encompassing DOCK8. Conclusion Multiplex ligation-dependent probe amplification and CMA yielded concordant results for 12 patients bearing CNV designated pathogenic or VOUS—likely pathogenic. Unambiguous diagnoses were achieved for eight patients (corresponding to 8.7% of the total studied population) by both MLPA and CMA, for one (1.09%) patient by karyotyping, and for one (1.09%) patient by FRAXA testing. MLPA and CMA thus achieved identical reliability with respect to clinically relevant findings. As such, MLPA could be useful as a fast and inexpensive test in patients with syndromic autism. The detection rate of potentially pathogenic variants (VOUS—likely pathogenic) achieved by CMA was higher than that for MLPA (13.04% vs. 4.35%). However, there was no corresponding difference in the rate of unambiguous diagnoses of ASD patients. In addition, the results obtained suggest that DOCK8 may play a role in the etiology of ASD.

16p13.11 microduplication in 45 new patients: refined clinical significance and genotype–phenotype correlations

2018 ◽  
Vol 57 (5) ◽  
pp. 301-307 ◽  
Author(s):  
Laïla Allach El Khattabi ◽  
Solveig Heide ◽  
Jean-Hubert Caberg ◽  
Joris Andrieux ◽  
Martine Doco Fenzy ◽  
...  
Keyword(s):  
Clinical Significance ◽  
Genetic Counselling ◽  
Essential Role ◽  
Disease Risk ◽  
Significant Risk ◽  
Aortic Disease ◽  
Autism Spectrum ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Cardiac Evaluation

BackgroundThe clinical significance of 16p13.11 duplications remains controversial while frequently detected in patients with developmental delay (DD), intellectual deficiency (ID) or autism spectrum disorder (ASD). Previously reported patients were not or poorly characterised. The absence of consensual recommendations leads to interpretation discrepancy and makes genetic counselling challenging. This study aims to decipher the genotype–phenotype correlations to improve genetic counselling and patients’ medical care.MethodsWe retrospectively analysed data from 16 013 patients referred to 12 genetic centers for DD, ID or ASD, and who had a chromosomal microarray analysis. The referring geneticists of patients for whom a 16p13.11 duplication was detected were asked to complete a questionnaire for detailed clinical and genetic data for the patients and their parents.ResultsClinical features are mainly speech delay and learning disabilities followed by ASD. A significant risk of cardiovascular disease was noted. About 90% of the patients inherited the duplication from a parent. At least one out of four parents carrying the duplication displayed a similar phenotype to the propositus. Genotype–phenotype correlations show no impact of the size of the duplicated segment on the severity of the phenotype. However, NDE1 and miR-484 seem to have an essential role in the neurocognitive phenotype.ConclusionOur study shows that 16p13.11 microduplications are likely pathogenic when detected in the context of DD/ID/ASD and supports an essential role of NDE1 and miR-484 in the neurocognitive phenotype. Moreover, it suggests the need for cardiac evaluation and follow-up and a large study to evaluate the aortic disease risk.

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 ◽  
...  
Keyword(s):  
Neurodevelopmental Disorders ◽  
Copy Number ◽  
Detection Rate ◽  
Clinical Performance ◽  
Copy Number Variants ◽  
Autism Spectrum ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Ultrahigh Resolution ◽  
Significant Difference

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.

scholarly journals Chromosomal Microarray Analysis in Children with Unexplained Developmental Delay/Intellectual Disability

2018 ◽  
Vol 08 (01) ◽  
pp. 001-009
Author(s):  
Pinar Arican ◽  
Berk Ozyilmaz ◽  
Dilek Cavusoglu ◽  
Pinar Gencpinar ◽  
Kadri Erdogan ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
De Novo ◽  
Copy Number Variants ◽  
Autism Spectrum ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Genetic Syndromes ◽  
Pathogenic Cnvs ◽  
Spectrum Disorders

AbstractChromosomal microarray (CMA) analysis for discovery of copy number variants (CNVs) is now recommended as a first-line diagnostic tool in patients with unexplained developmental delay/intellectual disability (DD/ID) and autism spectrum disorders. In this study, we present the results of CMA analysis in patients with DD/ID. Of 210 patients, pathogenic CNVs were detected in 26 (12%) and variants of uncertain clinical significance in 36 (17%) children. The diagnosis of well-recognized genetic syndromes was achieved in 12 patients. CMA analysis revealed pathogenic de novo CNVs, such as 11p13 duplication with new clinical features. Our results support the utility of CMA as a routine diagnostic test for unexplained DD/ID.

scholarly journals What Do Parents Think about Chromosomal Microarray Testing? A Qualitative Report from Parents of Children with Autism Spectrum Disorders

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Xu ◽  
Linda Crane Mitchell ◽  
Alice R. Richman ◽  
Kaitlyn Clawson
Keyword(s):  
Autism Spectrum Disorders ◽  
Genetic Testing ◽  
Copy Number Variants ◽  
Cultural Influences ◽  
Autism Spectrum ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Eastern Region ◽  
Children With Asd ◽  
Spectrum Disorders

Background. Chromosomal Microarray Analysis (CMA) is increasingly utilized to detect copy number variants among children and families affected with autism spectrum disorders (ASD). However, CMA is controversial due to possible ambiguous test findings, uncertain clinical implications, and other social and legal issues related to the test.Methods. Participants were parents of children with ASD residing in the North Eastern region of North Carolina, USA. We conducted individual, face-to-face interviews with 45 parents and inquired about their perceptions of CMA.Results. Three major themes dominated parents’ perceptions of CMA. None of the parents had ever heard of the test before and the majority of the parents postulated positive attitudes toward the test. Parents’ motivations in undergoing the test were attributed to finding a potential cause of ASD, to being better prepared for having another affected child, and to helping with future reproductive decisions. Perceived barriers included the cost of testing, risk/pain of CMA testing, and fear of test results.Conclusion. This study contributes to the understanding of psychosocial aspects and cultural influences towards adoption of genetic testing for ASD in clinical practice. Genetic education can aid informed decision-making related to CMA genetic testing among parents of children with ASD.

Gray Matter Heterotopia, Mental Retardation, Developmental Delay, Microcephaly, and Facial Dysmorphisms in a Boy with Ring Chromosome 6: A 10-Year Follow-Up and Literature Review

2018 ◽  
Vol 154 (4) ◽  
pp. 201-208 ◽  
Author(s):  
Shu Liu ◽  
Zhiqing Wang ◽  
Sisi Wei ◽  
Jinqun Liang ◽  
Nuan Chen ◽  
...  
Keyword(s):  
Developmental Delay ◽  
Gray Matter ◽  
De Novo ◽  
Ring Chromosome ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Chromosome 6 ◽  
Material Loss ◽  
Ring Chromosome 6

Ring chromosome 6, r(6), is an extremely rare cytogenetic abnormality with clinical heterogeneity which arises typically de novo. The phenotypes of r(6) can be highly variable, ranging from almost normal to severe malformations and neurological defects. Up to now, only 33 cases have been reported in the literature. In this 10-year follow-up study, we report a case presenting distinctive facial features, severe developmental delay, and gray matter heterotopia with r(6) and terminal deletions of 6p25.3 (115426-384174, 268 kb) and 6q26-27 (168697778-170732033, 2.03 Mb) encompassing 2 and 15 candidate genes, respectively, which were detected using G-banding karyotyping, FISH, and chromosomal microarray analysis. We also analyzed the available information on the clinical features of the reported r(6) cases in order to provide more valuable information on genotype-phenotype correlations. To the best of our knowledge, this is the first report of gray matter heterotopia manifested in a patient with r(6) in China, and the deletions of 6p and 6q in our case are the smallest with the precise size of euchromatic material loss currently known.

scholarly journals Fetal Anomalies Associated with Novel Pathogenic Variants in TMEM94

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 967
Author(s):  
Mohamed H. Al-Hamed ◽  
Nada Alsahan ◽  
Maha Tulbah ◽  
Wesam Kurdi ◽  
Wafa’a I. Ali ◽  
...  
Keyword(s):  
Developmental Disorder ◽  
Chromosomal Microarray ◽  
Global Developmental Delay ◽  
Facial Features ◽  
Chromosomal Microarray Analysis ◽  
Speech Delay ◽  
Loss Of Function ◽  
Pathogenic Variants ◽  
Antenatal Sonography ◽  
First Time

Background: Intellectual developmental disorder with cardiac defects and dysmorphic facies (IDDCDF, MIM 618316) is a newly described disorder. It is characterized by global developmental delay, intellectual disability and speech delay, congenital cardiac malformations, and dysmorphic facial features. Biallelic pathogenic variants of TMEM94 are associated with IDDCDF. Methods and Results: In a prenatal setting, where fetal abnormalities were detected using antenatal sonography, we used trio-exome sequencing (trio-ES) in conjunction with chromosomal microarray analysis (CMA) to identify two novel homozygous loss of function variants in the TMEM94 gene (c.606dupG and c.2729-2A>G) in two unrelated Saudi Arabian families. Conclusions: This study provides confirmation that TMEM94 variants may cause IDDCDF. For the first time we describe the pathogenicity of TMEM94 defects detected during the prenatal period.

scholarly journals Candidate Genes Associated with Delayed Neuropsychomotor Development and Seizures in a Patient with Ring Chromosome 20

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Thiago Corrêa ◽  
Amanda Cristina Venâncio ◽  
Marcial Francis Galera ◽  
Mariluce Riegel
Keyword(s):  
Candidate Genes ◽  
Protein Interactions ◽  
Neurological Diseases ◽  
Ring Chromosome ◽  
Molecular Data ◽  
Clinical Findings ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Nucleosome Assembly ◽  
Chromosome 20

Ring chromosome 20 (r20) is characterized by intellectual impairment, behavioral disorders, and refractory epilepsy. We report a patient presenting nonmosaic ring chromosome 20 followed by duplication and deletion in 20q13.33 with seizures, delayed neuropsychomotor development and language, mild hypotonia, low weight gain, and cognitive deficit. Chromosomal microarray analysis (CMA) enabled us to restrict a chromosomal segment and thus integrate clinical and molecular data with systems biology. With this approach, we were able to identify candidate genes that may help to explain the consequences of deletions in 20q13.33. In our analysis, we observed five hubs (ARFGAP1, HELZ2, COL9A3, PTK6, and EEF1A2), seven bottlenecks (CHRNA4, ARFRP1, GID8, COL9A3, PTK6, ZBTB46, and SRMS), and two H-B nodes (PTK6 and COL9A3). The candidate genes may play an important role in the developmental delay and seizures observed in r20 patients. Gene ontology included microtubule-based movement, nucleosome assembly, DNA repair, and cholinergic synaptic transmission. Defects in these bioprocesses are associated with the development of neurological diseases, intellectual disability, neuropathies, and seizures. Therefore, in this study, we can explore molecular cytogenetic data, identify proteins through network analysis of protein-protein interactions, and identify new candidate genes associated with the main clinical findings in patients with 20q13.33 deletions.

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