@article {1021, title = {Deletion of CTCF sites in the SHH locus alters enhancer-promoter interactions and leads to acheiropodia.}, journal = {Nat Commun}, volume = {12}, year = {2021}, month = {2021 04 16}, pages = {2282}, abstract = {

Acheiropodia, congenital limb truncation, is associated with homozygous deletions in the LMBR1 gene around ZRS, an enhancer regulating SHH during limb development. How these deletions lead to this phenotype is unknown. Using whole-genome sequencing, we fine-mapped the acheiropodia-associated region to 12 kb and show that it does not function as an enhancer. CTCF and RAD21 ChIP-seq together with 4C-seq and DNA FISH identify three CTCF sites within the acheiropodia-deleted region that mediate the interaction between the ZRS and the SHH promoter. This interaction is substituted with other CTCF sites centromeric to the ZRS in the disease state. Mouse knockouts of the orthologous 12 kb sequence have no apparent abnormalities, showcasing the challenges in modelling CTCF alterations in animal models due to inherent motif differences between species. Our results show that alterations in CTCF motifs can lead to a Mendelian condition due to altered enhancer-promoter interactions.

}, keywords = {Animals, Binding Sites, CCCTC-Binding Factor, Chromatin Immunoprecipitation Sequencing, Disease Models, Animal, Embryo, Mammalian, Enhancer Elements, Genetic, Exons, Extremities, Female, Foot Deformities, Congenital, Gene Expression Regulation, Developmental, Genetic Loci, Genetic Testing, Hand Deformities, Congenital, Hedgehog Proteins, Humans, Introns, Male, Membrane Proteins, Mice, Mice, Knockout, Promoter Regions, Genetic, Sequence Deletion, Species Specificity, Whole Genome Sequencing}, issn = {2041-1723}, doi = {10.1038/s41467-021-22470-z}, author = {Ushiki, Aki and Zhang, Yichi and Xiong, Chenling and Zhao, Jingjing and Georgakopoulos-Soares, Ilias and Kane, Lauren and Jamieson, Kirsty and Bamshad, Michael J and Nickerson, Deborah A and Shen, Yin and Lettice, Laura A and Silveira-Lucas, Elizabeth Lemos and Petit, Florence and Ahituv, Nadav} } @article {557, title = {Loss of function, missense, and intronic variants in NOTCH1 confer different risks for left ventricular outflow tract obstructive heart defects in two European cohorts.}, journal = {Genet Epidemiol}, volume = {43}, year = {2019}, month = {2019 03}, pages = {215-226}, abstract = {

Loss of function variants in NOTCH1 cause left ventricular outflow tract obstructive defects (LVOTO). However, the risk conferred by rare and noncoding variants in NOTCH1 for LVOTO remains largely uncharacterized. In a cohort of 49 families affected by hypoplastic left heart syndrome, a severe form of LVOTO, we discovered predicted loss of function NOTCH1 variants in 6\% of individuals. Rare or low-frequency missense variants were found in 16\% of families. To make a quantitative estimate of the genetic risk posed by variants in NOTCH1 for LVOTO, we studied associations of 400 coding and noncoding variants in NOTCH1 in 1,085 cases and 332,788 controls from the UK Biobank. Two rare intronic variants in strong linkage disequilibrium displayed significant association with risk for LVOTO amongst European-ancestry individuals. This result was replicated in an independent analysis of 210 cases and 68,762 controls of non-European and mixed ancestry. In conclusion, carrying rare predicted loss of function variants in NOTCH1 confer significant risk for LVOTO. In addition, the two intronic variants seem to be associated with an increased risk for these defects. Our approach demonstrates the utility of population-based data sets in quantifying the specific risk of individual variants for disease-related phenotypes.

}, keywords = {Cohort Studies, European Continental Ancestry Group, Female, Genetic Predisposition to Disease, Heart Defects, Congenital, Humans, Introns, Loss of Function Mutation, Male, Mutation, Missense, Pedigree, Receptor, Notch1, Risk Factors, Ventricular Outflow Obstruction, Whole Exome Sequencing}, issn = {1098-2272}, doi = {10.1002/gepi.22176}, author = {Helle, Emmi and C{\'o}rdova-Palomera, Aldo and Ojala, Tiina and Saha, Priyanka and Potiny, Praneetha and Gustafsson, Stefan and Ingelsson, Erik and Bamshad, Michael and Nickerson, Deborah and Chong, Jessica X and Ashley, Euan and Priest, James R} } @article {628, title = {Dissecting the Causal Mechanism of X-Linked Dystonia-Parkinsonism by Integrating Genome and Transcriptome Assembly.}, journal = {Cell}, volume = {172}, year = {2018}, month = {2018 02 22}, pages = {897-909.e21}, abstract = {

X-linked Dystonia-Parkinsonism (XDP) is a Mendelian~neurodegenerative disease that is endemic to the Philippines and is associated with a founder haplotype. We integrated multiple genome and transcriptome assembly technologies to narrow the causal mutation to the TAF1 locus, which included a SINE-VNTR-Alu (SVA) retrotransposition into intron 32 of the gene. Transcriptome analyses identified decreased expression of the canonical cTAF1 transcript among XDP probands, and de novo assembly~across multiple pluripotent stem-cell-derived neuronal lineages discovered aberrant TAF1 transcription that involved alternative splicing and intron retention (IR) in proximity to the SVA that was anti-correlated with overall TAF1 expression. CRISPR/Cas9 excision of the SVA rescued this XDP-specific~transcriptional signature and normalized TAF1 expression in probands. These data suggest an SVA-mediated aberrant transcriptional mechanism associated with XDP and may provide a roadmap for layered technologies and integrated assembly-based analyses for other unsolved Mendelian disorders.

}, keywords = {Alternative Splicing, Alu Elements, Base Sequence, Cohort Studies, CRISPR-Cas Systems, Dystonic Disorders, Family, Female, Genetic Diseases, X-Linked, Genetic Loci, Genome, Human, Haplotypes, High-Throughput Nucleotide Sequencing, Histone Acetyltransferases, Humans, Induced Pluripotent Stem Cells, Introns, Male, Minisatellite Repeats, Models, Genetic, Nerve Degeneration, Neural Stem Cells, Neurons, RNA, Messenger, Short Interspersed Nucleotide Elements, TATA-Binding Protein Associated Factors, Transcription Factor TFIID, Transcriptome}, issn = {1097-4172}, doi = {10.1016/j.cell.2018.02.011}, author = {Aneichyk, Tatsiana and Hendriks, William T and Yadav, Rachita and Shin, David and Gao, Dadi and Vaine, Christine A and Collins, Ryan L and Domingo, Aloysius and Currall, Benjamin and Stortchevoi, Alexei and Multhaupt-Buell, Trisha and Penney, Ellen B and Cruz, Lilian and Dhakal, Jyotsna and Brand, Harrison and Hanscom, Carrie and Antolik, Caroline and Dy, Marisela and Ragavendran, Ashok and Underwood, Jason and Cantsilieris, Stuart and Munson, Katherine M and Eichler, Evan E and Acu{\~n}a, Patrick and Go, Criscely and Jamora, R Dominic G and Rosales, Raymond L and Church, Deanna M and Williams, Stephen R and Garcia, Sarah and Klein, Christine and M{\"u}ller, Ulrich and Wilhelmsen, Kirk C and Timmers, H T Marc and Sapir, Yechiam and Wainger, Brian J and Henderson, Daniel and Ito, Naoto and Weisenfeld, Neil and Jaffe, David and Sharma, Nutan and Breakefield, Xandra O and Ozelius, Laurie J and Bragg, D Cristopher and Talkowski, Michael E} } @article {398, title = {Genome-Wide Association Studies and Meta-Analyses for Congenital Heart Defects.}, journal = {Circ Cardiovasc Genet}, volume = {10}, year = {2017}, month = {2017 Jun}, pages = {e001449}, abstract = {

BACKGROUND: Maternal and inherited (ie, case) genetic factors likely contribute to the pathogenesis of congenital heart defects, but it is unclear whether individual common variants confer a large risk.

METHODS AND RESULTS: To evaluate the relationship between individual common maternal/inherited genotypes and risk for heart defects, we conducted genome-wide association studies in 5 cohorts. Three cohorts were recruited at the Children{\textquoteright}s Hospital of Philadelphia: 670 conotruncal heart defect (CTD) case-parent trios, 317 left ventricular obstructive tract defect (LVOTD) case-parent trios, and 406 CTD cases (n=406) and 2976 pediatric controls. Two cohorts were recruited through the Pediatric Cardiac Genomics Consortium: 355 CTD trios and 192 LVOTD trios. We also conducted meta-analyses using the genome-wide association study results from the CTD cohorts, the LVOTD cohorts, and from the combined CTD and LVOTD cohorts. In the individual genome-wide association studies, several genome-wide significant associations (<=5{\texttimes}10) were observed. In our meta-analyses, 1 genome-wide significant association was detected: the case genotype for rs72820264, an intragenetic single-nucleotide polymorphism associated with LVOTDs (=2.1{\texttimes}10).

CONCLUSIONS: We identified 1 novel candidate region associated with LVOTDs and report on several additional regions with suggestive evidence for association with CTD and LVOTD. These studies were constrained by the relatively small samples sizes and thus have limited power to detect small to moderate associations. Approaches that minimize the multiple testing burden (eg, gene or pathway based) may, therefore, be required to uncover common variants contributing to the risk of these relatively rare conditions.

}, keywords = {Cohort Studies, Databases, Factual, Female, Gene Frequency, Genome-Wide Association Study, Genotype, Heart Defects, Congenital, Humans, Introns, Male, Membrane Proteins, Polymorphism, Single Nucleotide}, issn = {1942-3268}, doi = {10.1161/CIRCGENETICS.116.001449}, author = {Agopian, A J and Goldmuntz, Elizabeth and Hakonarson, Hakon and Sewda, Anshuman and Taylor, Deanne and Mitchell, Laura E} } @article {24, title = {Bi-allelic Mutations in PKD1L1 Are Associated with Laterality Defects in Humans.}, journal = {Am J Hum Genet}, volume = {99}, year = {2016}, month = {2016 Oct 06}, pages = {886-893}, abstract = {

Disruption of the establishment of left-right (L-R) asymmetry leads to situs anomalies ranging from situs inversus totalis (SIT) to situs ambiguus (heterotaxy). The genetic causes of laterality defects in humans are highly heterogeneous. Via whole-exome sequencing (WES), we identified homozygous mutations in PKD1L1 from three affected individuals in two unrelated families. PKD1L1 encodes a polycystin-1-like protein and its loss of function is known to cause laterality defects in mouse and medaka fish models. Family 1 had one fetus and one deceased child with heterotaxy and complex congenital heart malformations. WES identified a homozygous splicing mutation, c.6473+2_6473+3delTG, which disrupts the invariant splice donor site in intron 42, in both affected individuals. In the second family, a homozygous c.5072G>C (p.Cys1691Ser) missense mutation was detected in an individual with SIT and congenital heart disease. The p.Cys1691Ser substitution affects a highly conserved cysteine residue and is predicted by molecular modeling to disrupt a disulfide bridge essential for the proper folding of the G protein-coupled receptor proteolytic site (GPS) motif. Damaging effects associated with substitutions of this conserved cysteine residue in the GPS motif have also been reported in other genes, namely GPR56, BAI3, and PKD1 in human and lat-1 in C.~elegans, further supporting the likely pathogenicity of p.Cys1691Ser in PKD1L1. The identification of bi-allelic PKD1L1 mutations recapitulates previous findings regarding phenotypic consequences of loss of function of the orthologous genes in mice and medaka fish and further expands our understanding of genetic contributions to laterality defects in humans.

}, keywords = {Alleles, Amino Acid Motifs, Amino Acid Sequence, Animals, Caenorhabditis elegans, Cysteine, Exome, Female, Fetal Diseases, Functional Laterality, Heart Defects, Congenital, Heterotaxy Syndrome, Homozygote, Humans, Infant, Newborn, Introns, Male, Membrane Proteins, Mice, Middle Aged, Models, Molecular, Mutation, Mutation, Missense, Oryzias, Pedigree, RNA Splicing, Situs Inversus}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.07.011}, author = {Vetrini, Francesco and D{\textquoteright}Alessandro, Lisa C A and Akdemir, Zeynep C and Braxton, Alicia and Azamian, Mahshid S and Eldomery, Mohammad K and Miller, Kathryn and Kois, Chelsea and Sack, Virginia and Shur, Natasha and Rijhsinghani, Asha and Chandarana, Jignesh and Ding, Yan and Holtzman, Judy and Jhangiani, Shalini N and Muzny, Donna M and Gibbs, Richard A and Eng, Christine M and Hanchard, Neil A and Harel, Tamar and Rosenfeld, Jill A and Belmont, John W and Lupski, James R and Yang, Yaping} } @article {103, title = {Chimeric transcripts resulting from complex duplications in chromosome Xq28.}, journal = {Hum Genet}, volume = {135}, year = {2016}, month = {2016 Feb}, pages = {253-6}, abstract = {

Gene fusions have been observed in somatic alterations in cancer and in schizophrenia. However, the underlying mechanism(s) for their formation are poorly understood. We experimentally demonstrated the expression of splicing variants of in silico predicted chimeric genes F8/CSAG1 and BCAP31/TEX28 in two individuals with de novo complex genomic rearrangements of Xq28; F8/CSAG1 includes exonization of an ERVL-MaLR intronic repetitive element. We provide evidence that replicative repair may contribute to exon shuffling processes and diversify the repertoire of expressed transcripts.

}, keywords = {Antigens, Neoplasm, Base Sequence, Cell Line, Chromosomes, Human, X, Exons, Gene Duplication, Gene Expression Regulation, Gene Rearrangement, Humans, Introns, Male, Membrane Proteins, Molecular Sequence Data, Neoplasm Proteins, RNA Splicing, RNA, Messenger, Transcription, Genetic}, issn = {1432-1203}, doi = {10.1007/s00439-015-1614-x}, author = {Zuccherato, Luciana W and Alleva, Benjamin and Whiters, Marjorie A and Carvalho, Claudia M B and Lupski, James R} } @article {83, title = {Mitral regurgitation as a phenotypic manifestation of nonphotosensitive trichothiodystrophy due to a splice variant in MPLKIP.}, journal = {BMC Med Genet}, volume = {17}, year = {2016}, month = {2016 Feb 16}, pages = {13}, abstract = {

BACKGROUND: Nonphotosensitive trichothiodystrophy (TTDN) is a rare autosomal recessive disorder of neuroectodermal origin. The condition is marked by hair abnormalities, intellectual impairment, nail dystrophies and susceptibility to infections but with no UV sensitivity.

METHODS: We identified three consanguineous Pakistani families with varied TTDN features and used homozygosity mapping, linkage analysis, and Sanger and exome sequencing in order to identify pathogenic variants. Haplotype analysis was performed and haplotype age estimated. A splicing assay was used to validate the effect of the MPLKIP splice variant on expression.

RESULTS: Affected individuals from all families exhibit several TTDN features along with a heart-specific feature, i.e. mitral regurgitation. Exome sequencing in the probands from families ED168 and ED241 identified a homozygous splice mutation c.339 + 1G > A within MPLKIP. The same splice variant co-segregates with TTDN in a third family ED210. The MPLKIP splice variant was not found in public databases, e.g. the Exome Aggregation Consortium, and in unrelated Pakistani controls. Functional analysis of the splice variant confirmed intron retention, which leads to protein truncation and loss of a phosphorylation site. Haplotype analysis identified a 585.1-kb haplotype which includes the MPLKIP variant, supporting the existence of a founder haplotype that is estimated to be 25,900 years old.

CONCLUSION: This study extends the allelic and phenotypic spectra of MPLKIP-related TTDN, to include a splice variant that causes cardiomyopathy as part of the TTDN phenotype.

}, keywords = {Adaptor Proteins, Signal Transducing, Adolescent, Adult, Alleles, Asian Continental Ancestry Group, Child, Cloning, Molecular, Exome, Female, Genetic Linkage, Haplotypes, HEK293 Cells, Homozygote, Humans, Introns, Male, Mitral Valve Insufficiency, Pakistan, Pedigree, Phenotype, Polymorphism, Single Nucleotide, RNA Splicing, Sequence Analysis, DNA, Trichothiodystrophy Syndromes, Young Adult}, issn = {1471-2350}, doi = {10.1186/s12881-016-0275-5}, author = {Shah, Khadim and Ali, Raja Hussain and Ansar, Muhammad and Lee, Kwanghyuk and Chishti, Muhammad Salman and Abbe, Izoduwa and Li, Biao and Smith, Joshua D and Nickerson, Deborah A and Shendure, Jay and Coucke, Paul J and Steyaert, Wouter and Bamshad, Michael J and Santos-Cortez, Regie Lyn P and Leal, Suzanne M and Ahmad, Wasim} } @article {640, title = {Characterization of a New DGKE Intronic Mutation in Genetically Unsolved Cases of Familial Atypical Hemolytic Uremic Syndrome.}, journal = {Clin J Am Soc Nephrol}, volume = {10}, year = {2015}, month = {2015 Jun 05}, pages = {1011-9}, abstract = {

BACKGROUND AND OBJECTIVES: Genetic and acquired abnormalities causing dysregulation of the complement alternative pathway contribute to atypical hemolytic uremic syndrome (aHUS), a rare disorder characterized by thrombocytopenia, nonimmune microangiopathic hemolytic anemia, and acute kidney failure. However, in a substantial proportion of patients the disease-associated alterations are still unknown.

DESIGN, SETTING, PARTICIPANTS, \& MEASUREMENTS: Whole-exome and whole-genome sequencing were performed in two unrelated families with infantile recessive aHUS. Sequencing of cDNA from affected individuals was used to test for the presence of aberrant mRNA species. Expression of mutant diacylglycerol kinase epsilon (DGKE) protein was evaluated with western blotting.

RESULTS: Whole-exome sequencing analysis with conventional variant filtering parameters did not reveal any obvious candidate mutation in the first family. The report of aHUS-associated mutations in DGKE, encoding DGKE, led to re-examination of the noncoding DGKE variants obtained from next-generation sequencing, allowing identification of a novel intronic DGKE mutation (c.888+40A>G) that segregated with disease. Sequencing of cDNA from affected individuals revealed aberrant forms of DGKE mRNA predicted to cause profound abnormalities in the protein catalytic site. By whole-genome sequencing, the same mutation was found in compound heterozygosity with a second nonsense DGKE mutation in all affected siblings of another unrelated family. Homozygous and compound heterozygous patients presented similar clinical features, including aHUS presentation in the first year of life, multiple relapsing episodes, and proteinuria, which are prototypical of DGKE-associated aHUS.

CONCLUSIONS: This is the first report of a mutation located beyond the exon-intron boundaries in aHUS. Intronic mutations such as these are underreported because conventional filtering parameters used to process next-generation sequencing data routinely exclude these regions from downstream analyses in both research and clinical settings. The results suggest that analysis of noncoding regions of aHUS-associated genes coupled with mRNA sequencing might provide a tool to explain genetically unsolved aHUS cases.

}, keywords = {Adolescent, Atypical Hemolytic Uremic Syndrome, Base Sequence, Blotting, Western, Child, Diacylglycerol Kinase, DNA Mutational Analysis, Female, Genetic Association Studies, Genetic Predisposition to Disease, Heterozygote, Homozygote, Humans, Infant, Introns, Male, Molecular Sequence Data, Mutation, Phenotype, Predictive Value of Tests, Risk Factors}, issn = {1555-905X}, doi = {10.2215/CJN.08520814}, author = {Mele, Caterina and Lemaire, Mathieu and Iatropoulos, Paraskevas and Piras, Rossella and Bresin, Elena and Bettoni, Serena and Bick, David and Helbling, Daniel and Veith, Regan and Valoti, Elisabetta and Donadelli, Roberta and Murer, Luisa and Neunh{\"a}userer, Maria and Breno, Matteo and Fremeaux-Bacchi, Veronique and Lifton, Richard and Remuzzi, Giuseppe and Noris, Marina} } @article {153, title = {Continued lessons from the INS gene: an intronic mutation causing diabetes through a novel mechanism.}, journal = {J Med Genet}, volume = {52}, year = {2015}, month = {2015 Sep}, pages = {612-6}, abstract = {

BACKGROUND: Diabetes in neonates usually has a monogenic aetiology; however, the cause remains unknown in 20-30\%. Heterozygous INS mutations represent one of the most common gene causes of neonatal diabetes mellitus.

METHODS: Clinical and functional characterisation of a novel homozygous intronic mutation (c.187+241G>A) in the insulin gene in a child identified through the Monogenic Diabetes Registry (http://monogenicdiabetes.uchicago.edu).

RESULTS: The proband had insulin-requiring diabetes from birth. Ultrasonography revealed a structurally normal pancreas and C-peptide was undetectable despite readily detectable amylin, suggesting the presence of dysfunctional β cells. Whole-exome sequencing revealed the novel mutation. In silico analysis predicted a mutant mRNA product resulting from preferential recognition of a newly created splice site. Wild-type and mutant human insulin gene constructs were derived and transiently expressed in INS-1 cells. We confirmed the predicted transcript and found an additional transcript created via an ectopic splice acceptor site.

CONCLUSIONS: Dominant INS mutations cause diabetes via a mutated translational product causing endoplasmic reticulum stress. We describe a novel mechanism of diabetes, without β cell death, due to creation of two unstable mutant transcripts predicted to undergo nonsense and non-stop-mediated decay, respectively. Our discovery may have broader implications for those with insulin deficiency later in life.

}, keywords = {Diabetes Mellitus, Humans, Infant, Insulin, Regular, Human, Introns, Mutation, Sequence Analysis, DNA}, issn = {1468-6244}, doi = {10.1136/jmedgenet-2015-103220}, author = {Carmody, David and Park, Soo-Young and Ye, Honggang and Perrone, Marie E and Alkorta-Aranburu, G and Highland, Heather M and Hanis, Craig L and Philipson, Louis H and Bell, Graeme I and Greeley, Siri Atma W} }