@article {158, title = {Phenotypic and protein localization heterogeneity associated with AHDC1 pathogenic protein-truncating alleles in Xia-Gibbs syndrome.}, journal = {Hum Mutat}, volume = {42}, year = {2021}, month = {2021 May}, pages = {577-591}, abstract = {

Xia-Gibbs syndrome (XGS) is a rare Mendelian disease typically caused by de novo stop-gain or frameshift mutations in the AT-hook DNA binding motif containing 1 (AHDC1) gene. Patients usually present in early infancy with hypotonia and developmental delay and later exhibit intellectual disability (ID). The overall presentation is variable, however, and the emerging clinical picture is still evolving. A detailed phenotypic analysis of 34 XGS individuals revealed five core phenotypes (delayed motor milestones, speech delay, low muscle tone, ID, and hypotonia) in more than 80\% of individuals and an additional 12 features that occurred more variably. Seizures and scoliosis were more frequently associated with truncations that arise before the midpoint of the protein although the occurrence of most features could not be predicted by the mutation position. Transient expression of wild type and different patient truncated AHDC1 protein forms in human cell lines revealed abnormal patterns of nuclear localization including a diffuse distribution of a short truncated form and nucleolar aggregation in mid-protein truncated forms. Overall, both the occurrence of variable phenotypes and the different distribution of the expressed protein reflect the heterogeneity of this syndrome.

}, issn = {1098-1004}, doi = {10.1002/humu.24190}, author = {Khayat, Michael M and Li, He and Chander, Varuna and Hu, Jianhong and Hansen, Adam W and Li, Shoudong and Traynelis, Josh and Shen, Hua and Weissenberger, George and Stossi, Fabio and Johnson, Hannah L and Lupski, James R and Posey, Jennifer E and Sabo, Aniko and Meng, Qingchang and Murdock, David R and Wangler, Michael and Gibbs, Richard A} } @article {106, title = {Community-based recruitment and exome sequencing indicates high diagnostic yield in adults with intellectual disability.}, journal = {Mol Genet Genomic Med}, volume = {8}, year = {2020}, month = {2020 10}, pages = {e1439}, abstract = {

BACKGROUND: Establishing a genetic diagnosis for individuals with intellectual disability (ID) benefits patients and their families as it may inform the prognosis, lead to appropriate therapy, and facilitate access to medical and supportive services. Exome sequencing has been successfully applied in a diagnostic setting, but most clinical exome referrals are pediatric patients, with many adults with ID lacking a comprehensive genetic evaluation.

METHODS: Our unique recruitment strategy involved partnering with service and education providers for individuals with ID. We performed exome sequencing and analysis, and clinical variant interpretation for each recruited family.

RESULTS: All five families enrolled in the study opted-in for the return of genetic results. In three out of five families exome sequencing analysis identified pathogenic or likely pathogenic variants in KANSL1, TUSC3, and MED13L genes. Families discussed the results and any potential medical follow-up in an appointment with a board certified clinical geneticist.

CONCLUSION: Our study suggests high yield of exome sequencing as a diagnostic tool in adult patients with ID who have not undergone comprehensive sequencing-based genetic testing. Research studies including an option of return of results through a genetic clinic could help minimize the disparity in exome diagnostic testing between pediatric and adult patients with ID.

}, keywords = {Adult, Female, Genetic Testing, Humans, Independent Living, Intellectual Disability, Male, Mediator Complex, Membrane Proteins, Nuclear Proteins, Patient Selection, Sensitivity and Specificity, Tumor Suppressor Proteins, Whole Exome Sequencing}, issn = {2324-9269}, doi = {10.1002/mgg3.1439}, author = {Sabo, Aniko and Murdock, David and Dugan, Shannon and Meng, Qingchang and Gingras, Marie-Claude and Hu, Jianhong and Muzny, Donna and Gibbs, Richard} } @article {108, title = {Next Generation Sequencing of 134 Children with Autism Spectrum Disorder and Regression.}, journal = {Genes (Basel)}, volume = {11}, year = {2020}, month = {2020 07 25}, abstract = {

Approximately 30\% of individuals with autism spectrum disorder (ASD) experience developmental regression, the etiology of which remains largely unknown. We performed a complete literature search and identified 47 genes that had been implicated in such cases. We sequenced these genes in a preselected cohort of 134 individuals with regressive autism. In total, 16 variants in 12 genes with evidence supportive of pathogenicity were identified. They were classified as variants of uncertain significance based on ACMG standards and guidelines. Among these were recurring variants in and , variants in genes that were linked to syndromic forms of ASD (, , , , , and ), and variants in the form of oligogenic heterozygosity (, , and ).

}, keywords = {Autism Spectrum Disorder, Child, Child, Preschool, Cohort Studies, Disease Progression, Female, Gene Expression Regulation, Genetic Markers, Genetic Predisposition to Disease, High-Throughput Nucleotide Sequencing, Humans, Infant, Male, Mutation}, issn = {2073-4425}, doi = {10.3390/genes11080853}, author = {Yin, Jiani and Chun, Chun-An and Zavadenko, Nikolay N and Pechatnikova, Natalia L and Naumova, Oxana Yu and Doddapaneni, Harsha V and Hu, Jianhong and Muzny, Donna M and Schaaf, Christian P and Grigorenko, Elena L} } @article {54, title = {Atlas-CNV: a validated approach to call single-exon CNVs in the eMERGESeq gene panel.}, journal = {Genet Med}, volume = {21}, year = {2019}, month = {2019 Sep}, pages = {2135-2144}, abstract = {

PURPOSE: To provide a validated method to confidently identify exon-containing copy-number variants (CNVs), with a low false discovery rate (FDR), in targeted sequencing data from a clinical laboratory with particular focus on single-exon CNVs.

METHODS: DNA sequence coverage data are normalized within each sample and subsequently exonic CNVs are identified in a batch of samples, when the target log ratio of the sample to the batch median exceeds defined thresholds. The quality of exonic CNV calls is assessed by C-scores (Z-like scores) using thresholds derived from gold standard samples and simulation studies. We integrate an ExonQC threshold to lower FDR and compare performance with alternate software (VisCap).

RESULTS: Thirteen CNVs were used as a truth set to validate Atlas-CNV and compared with VisCap. We demonstrated FDR reduction in validation, simulation, and 10,926 eMERGESeq samples without sensitivity loss. Sixty-four multiexon and 29 single-exon CNVs with high C-scores were assessed by~Multiplex Ligation-dependent Probe Amplification (MLPA).

CONCLUSION: Atlas-CNV is validated as a method to identify exonic CNVs in targeted sequencing data generated in the clinical laboratory. The ExonQC and C-score assignment can reduce FDR (identification of targets with high variance) and improve calling accuracy of single-exon CNVs respectively. We propose guidelines and criteria to identify high confidence single-exon CNVs.

}, issn = {1530-0366}, doi = {10.1038/s41436-019-0475-4}, author = {Chiang, Theodore and Liu, Xiuping and Wu, Tsung-Jung and Hu, Jianhong and Sedlazeck, Fritz J and White, Simon and Schaid, Daniel and Andrade, Mariza de and Jarvik, Gail P and Crosslin, David and Stanaway, Ian and Carrell, David S and Connolly, John J and Hakonarson, Hakon and Groopman, Emily E and Gharavi, Ali G and Fedotov, Alexander and Bi, Weimin and Leduc, Magalie S and Murdock, David R and Jiang, Yunyun and Meng, Linyan and Eng, Christine M and Wen, Shu and Yang, Yaping and Muzny, Donna M and Boerwinkle, Eric and Salerno, William and Venner, Eric and Gibbs, Richard A} } @article {61, title = {Genetic architecture of laterality defects revealed by whole exome sequencing.}, journal = {Eur J Hum Genet}, volume = {27}, year = {2019}, month = {2019 Apr}, pages = {563-573}, abstract = {

Aberrant left-right patterning in the developing human embryo can lead to a broad spectrum of congenital malformations. The causes of most laterality defects are not known, with variants in established genes accounting for <20\% of cases. We sought to characterize the genetic spectrum of these conditions by performing whole-exome sequencing of 323 unrelated laterality cases. We investigated the role of rare, predicted-damaging variation in 1726 putative laterality candidate genes derived from model organisms, pathway analyses, and human phenotypes. We also evaluated the contribution of homo/hemizygous exon deletions and gene-based burden of rare variation. A total of 28 candidate variants (26 rare predicted-damaging variants and 2 hemizygous deletions) were identified, including variants in genes known to cause heterotaxy and primary ciliary dyskinesia (ACVR2B, NODAL, ZIC3, DNAI1, DNAH5, HYDIN, MMP21), and genes without a human phenotype association, but with prior evidence for a role in embryonic laterality or cardiac development. Sanger validation of the latter variants in probands and their parents revealed no de novo variants, but apparent transmitted heterozygous (ROCK2, ISL1, SMAD2), and hemizygous (RAI2, RIPPLY1) variant patterns. Collectively, these variants account for 7.1\% of our study subjects. We also observe evidence for an excess burden of rare, predicted loss-of-function variation in PXDNL and BMS1- two genes relevant to the broader laterality phenotype. These findings highlight potential new genes in the development of laterality defects, and suggest extensive locus heterogeneity and complex genetic models in this class of birth defects.

}, issn = {1476-5438}, doi = {10.1038/s41431-018-0307-z}, author = {Li, Alexander H and Hanchard, Neil A and Azamian, Mahshid and D{\textquoteright}Alessandro, Lisa C A and Coban-Akdemir, Zeynep and Lopez, Keila N and Hall, Nancy J and Dickerson, Heather and Nicosia, Annarita and Fernbach, Susan and Boone, Philip M and Gambin, Tomaz and Karaca, Ender and Gu, Shen and Yuan, Bo and Jhangiani, Shalini N and Doddapaneni, HarshaVardhan and Hu, Jianhong and Dinh, Huyen and Jayaseelan, Joy and Muzny, Donna and Lalani, Seema and Towbin, Jeffrey and Penny, Daniel and Fraser, Charles and Martin, James and Lupski, James R and Gibbs, Richard A and Boerwinkle, Eric and Ware, Stephanie M and Belmont, John W} }