Novel IQCE Variations Confirm Its Role in Postaxial Polydactyly and Cause
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ANALYTICAL SCIENCES NOVEMBER 2020, VOL. 36 1 2020 © The Japan Society for Analytical Chemistry Supporting Information Fig. S1 Detailed MS/MS data of myoglobin. 17 2 ANALYTICAL SCIENCES NOVEMBER 2020, VOL. 36 Table S1 : The protein names (antigens) identified by pH 2.0 solution in the eluted-fraction. These proteins were identified one or more out of six analyses. Accession Description P08908 5-hydroxytryptamine receptor 1A OS=Homo sapiens GN=HTR1A PE=1 SV=3 - [5HT1A_HUMAN] Q9NRR6 72 kDa inositol polyphosphate 5-phosphatase OS=Homo sapiens GN=INPP5E PE=1 SV=2 - [INP5E_HUMAN] P82987 ADAMTS-like protein 3 OS=Homo sapiens GN=ADAMTSL3 PE=2 SV=4 - [ATL3_HUMAN] Q9Y6K8 Adenylate kinase isoenzyme 5 OS=Homo sapiens GN=AK5 PE=1 SV=2 - [KAD5_HUMAN] P02763 Alpha-1-acid glycoprotein 1 OS=Homo sapiens GN=ORM1 PE=1 SV=1 - [A1AG1_HUMAN] P19652 Alpha-1-acid glycoprotein 2 OS=Homo sapiens GN=ORM2 PE=1 SV=2 - [A1AG2_HUMAN] P01011 Alpha-1-antichymotrypsin OS=Homo sapiens GN=SERPINA3 PE=1 SV=2 - [AACT_HUMAN] P01009 Alpha-1-antitrypsin OS=Homo sapiens GN=SERPINA1 PE=1 SV=3 - [A1AT_HUMAN] P04217 Alpha-1B-glycoprotein OS=Homo sapiens GN=A1BG PE=1 SV=4 - [A1BG_HUMAN] P08697 Alpha-2-antiplasmin OS=Homo sapiens GN=SERPINF2 PE=1 SV=3 - [A2AP_HUMAN] P02765 Alpha-2-HS-glycoprotein OS=Homo sapiens GN=AHSG PE=1 SV=1 - [FETUA_HUMAN] P01023 Alpha-2-macroglobulin OS=Homo sapiens GN=A2M PE=1 SV=3 - [A2MG_HUMAN] P01019 Angiotensinogen OS=Homo sapiens GN=AGT PE=1 SV=1 - [ANGT_HUMAN] Q9NQ90 Anoctamin-2 OS=Homo sapiens GN=ANO2 PE=1 SV=2 - [ANO2_HUMAN] P01008 Antithrombin-III -
THE ROLE of HOMEODOMAIN TRANSCRIPTION FACTOR IRX5 in CARDIAC CONTRACTILITY and HYPERTROPHIC RESPONSE by © COPYRIGHT by KYOUNG H
THE ROLE OF HOMEODOMAIN TRANSCRIPTION FACTOR IRX5 IN CARDIAC CONTRACTILITY AND HYPERTROPHIC RESPONSE By KYOUNG HAN KIM A THESIS SUBMITTED IN CONFORMITY WITH THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY GRADUATE DEPARTMENT OF PHYSIOLOGY UNIVERSITY OF TORONTO © COPYRIGHT BY KYOUNG HAN KIM (2011) THE ROLE OF HOMEODOMAIN TRANSCRIPTION FACTOR IRX5 IN CARDIAC CONTRACTILITY AND HYPERTROPHIC RESPONSE KYOUNG HAN KIM DOCTOR OF PHILOSOPHY GRADUATE DEPARTMENT OF PHYSIOLOGY UNIVERSITY OF TORONTO 2011 ABSTRACT Irx5 is a homeodomain transcription factor that negatively regulates cardiac fast transient + outward K currents (Ito,f) via the KV4.2 gene and is thereby a major determinant of the transmural repolarization gradient. While Ito,f is invariably reduced in heart disease and changes in Ito,f can modulate both cardiac contractility and hypertrophy, less is known about a functional role of Irx5, and its relationship with Ito,f, in the normal and diseased heart. Here I show that Irx5 plays crucial roles in the regulation of cardiac contractility and proper adaptive hypertrophy. Specifically, Irx5-deficient (Irx5-/-) hearts had reduced cardiac contractility and lacked the normal regional difference in excitation-contraction with decreased action potential duration, Ca2+ transients and myocyte shortening in sub-endocardial, but not sub-epicardial, myocytes. In addition, Irx5-/- mice showed less cardiac hypertrophy, but increased interstitial fibrosis and greater contractility impairment following pressure overload. A defect in hypertrophic responses in Irx5-/- myocardium was confirmed in cultured neonatal mouse ventricular myocytes, exposed to norepinephrine while being restored with Irx5 replacement. Interestingly, studies using mice ii -/- virtually lacking Ito,f (i.e. KV4.2-deficient) showed that reduced contractility in Irx5 mice was completely restored by loss of KV4.2, whereas hypertrophic responses to pressure-overload in hearts remained impaired when both Irx5 and Ito,f were absent. -
Accepted Version
Article Genetic Control of Gonadal Sex Determination and Development STEVANT, Isabelle, NEF, Serge Abstract Sex determination is the process by which the bipotential gonads develop as either testes or ovaries. With two distinct potential outcomes, the gonadal primordium offers a unique model for the study of cell fate specification and how distinct cell populations diverge from multipotent progenitors. This review focuses on recent advances in our understanding of the genetic programs and epigenetic mechanisms that regulate gonadal sex determination and the regulation of cell fate commitment in the bipotential gonads. We rely primarily on mouse data to illuminate the complex and dynamic genetic programs controlling cell fate decision and sex-specific cell differentiation during gonadal formation and gonadal sex determination. Reference STEVANT, Isabelle, NEF, Serge. Genetic Control of Gonadal Sex Determination and Development. Trends in Genetics, 2019 PMID : 30902461 DOI : 10.1016/j.tig.2019.02.004 Available at: http://archive-ouverte.unige.ch/unige:115790 Disclaimer: layout of this document may differ from the published version. 1 / 1 Trends in Genetics Genetic control of sex determination and gonad development --Manuscript Draft-- Manuscript Number: TIGS-D-18-00173R1 Article Type: Review Keywords: sex determination; ovary; testis; lineage specification; gene expression; epigenetic regulation Corresponding Author: Serge Nef geneva, SWITZERLAND First Author: Isabelle Stévant Order of Authors: Isabelle Stévant Serge Nef Abstract: Sex determination is the process by which the bipotential gonads develop as either testes or ovaries. With two distinct potential outomes, the gonadal primordium offers a unique model for the study of cell fate specification and how distinct cell populations diverge from multipotent progenitors. -
ZNF354C Is a Transcriptional Repressor That Inhibits Endothelial Angiogenic Sprouting James A
www.nature.com/scientificreports OPEN ZNF354C is a transcriptional repressor that inhibits endothelial angiogenic sprouting James A. Oo1,3, Barnabas Irmer1, Stefan Günther2, Timothy Warwick1, Katalin Pálf1, Judit Izquierdo Ponce1, Tom Teichmann1, Beatrice Pfüger‑Müller1,3, Ralf Gilsbach1,3, Ralf P. Brandes1,3 & Matthias S. Leisegang1,3* Zinc fnger proteins (ZNF) are a large group of transcription factors with diverse functions. We recently discovered that endothelial cells harbour a specifc mechanism to limit the action of ZNF354C, whose function in endothelial cells is unknown. Given that ZNF354C has so far only been studied in bone and tumour, its function was determined in endothelial cells. ZNF354C is expressed in vascular cells and localises to the nucleus and cytoplasm. Overexpression of ZNF354C in human endothelial cells results in a marked inhibition of endothelial sprouting. RNA‑sequencing of human microvascular endothelial cells with and without overexpression of ZNF354C revealed that the protein is a potent transcriptional repressor. ZNF354C contains an active KRAB domain which mediates this suppression as shown by mutagenesis analysis. ZNF354C interacts with dsDNA, TRIM28 and histones, as observed by proximity ligation and immunoprecipitation. Moreover, chromatin immunoprecipitation revealed that the ZNF binds to specifc endothelial‑relevant target‑gene promoters. ZNF354C suppresses these genes as shown by CRISPR/Cas knockout and RNAi. Inhibition of endothelial sprouting by ZNF354C is dependent on the amino acids DV and MLE of the KRAB domain. These results demonstrate that ZNF354C is a repressive transcription factor which acts through a KRAB domain to inhibit endothelial angiogenic sprouting. Te vascular system is controlled by numerous signaling pathways and growth factors which all contribute to the regulation of gene expression. -
Trastuzumab Modulates the Protein Cargo of Extracellular Vesicles Released by ERBB2+ Breast Can‐ Cer Cells
Supplementary Material: Trastuzumab Modulates the Protein Cargo of Extracellular Vesicles Released by ERBB2+ Breast Can‐ cer Cells Silvia Marconi, Sara Santamaria, Martina Bartolucci, Sara Stigliani, Cinzia Aiello, Maria Cristina Gagliani, Grazia Bellese, Andrea Petretto, Katia Cortese and Patrizio Castagnola Table S1. Antibodies used in the study. Antibody Catalog number Manufacturer Anti‐ALIX sc‐271975 Santa Cruz1 Anti‐CD9 PA5‐85955 Thermofisher Scientific2 Anti‐CD63 sc‐15363 Santa Cruz Anti‐ErbB2 (9G6) sc‐08 Santa Cruz Anti‐GAPDH 14C10 Cell signaling3 Anti‐HSP90 sc‐13119 Santa Cruz 1 Dallas, TX, USA; 2 Waltham, MA, USA; 3 Danvers, MA, USA. Table S2. Differentially regulated proteins by trastuzumab Tz treatment in extracellular vesicles EVs purified from SKBR‐ 3 cells with a statistically significant p‐value resulted from Studentʹs T‐test. The gene symbols coding for proteins downregulated by Tz (and hence upregulated in IgG treated cells) are highlighted in red while proteins upregulated by Tz are highlighted in blue. Official Gene Symbol 1 Gene product (Protein name) ACVR1B Activin A receptor type 1B ANO1 Anoctamin 1 ARFGEF2 ADP Ribosylation Factor Guanine Nucleotide Exchange Factor 2 BTN2A1 Butyrophilin subfamily 2 member A1 CIAPIN1 Cytokine Induced Apoptosis Inhibitor 1 CIT Citron Rho‐Interacting Serine/Threonine Kinase CPPED1 Calcineurin Like Phosphoesterase Domain Containing 1 DNAH7 Dynein Axonemal Heavy Chain 7 EIF3F Eukaryotic translation initiation factor 3 subunit F ESD Esterase D ESYT2 Extended Synaptotagmin 2 F2RL1 F2R Like Trypsin Receptor 1 RIPOR3 RIPOR Family Member 3 FZD6 Frizzled‐6 GAN Gigaxonin GTPBP2 GTP‐binding protein 2 GUCD1 Guanylyl Cyclase Domain Containing 1 HNRNPM Heterogeneous nuclear ribonucleoprotein M LMAN2 Lectin, Mannose Binding 2 LRRC8A Volume‐regulated anion channel subunit LRRC8A NOTCH4 Notch Receptor 4 NT5C2 5ʹ‐Nucleotidase, Cytosolic II PCID2 PCI domain‐containing 2 PDCD5 Programmed cell death 5 PHLDB3 Pleckstrin homology like domain family B member 3 PLAA Phospholipase A2 activating protein Membranes 2021, 11, 199. -
Novel Observations from Next-Generation RNA Sequencing of Highly Purified Human Adult and Fetal Islet Cell Subsets
3172 Diabetes Volume 64, September 2015 David M. Blodgett,1 Anetta Nowosielska,2 Shaked Afik,3 Susanne Pechhold,1 Anthony J. Cura,1 Norman J. Kennedy,4 Soyoung Kim,2 Alper Kucukural,5 Roger J. Davis,6 Sally C. Kent,1 Dale L. Greiner,2 Manuel G. Garber,3 David M. Harlan,1 and Philip diIorio2† Novel Observations From Next-Generation RNA Sequencing of Highly Purified Human Adult and Fetal Islet Cell Subsets Diabetes 2015;64:3172–3181 | DOI: 10.2337/db15-0039 Understanding distinct gene expression patterns of blindness, kidney failure, amputation, lost work, and pre- normal adult and developing fetal human pancreatic a- mature mortality (2,3). While diabetes is easily diagnosed and b-cells is crucial for developing stem cell therapies, by simple blood glucose measurements, it ultimately islet regeneration strategies, and therapies designed to results from a loss of functional b-cell mass. We need increase b-cell function in patients with diabetes (type 1 to better understand the molecular mediators driving or 2). Toward that end, we have developed methods to that loss and limited b-cell regeneration capacity (4,5). highly purify a-, b-, and d-cells from human fetal and This knowledge gap exists because it has not previously adult pancreata by intracellular staining for the cell- been possible to study homogeneous, highly enriched en- specific hormone content, sorting the subpopulations docrine cell populations from human islets. Recent stud- by flow cytometry, and, using next-generation RNA se- ies have reported expression profiles on whole islets (6) quencing, we report the detailed transcriptomes of fetal and individual cell types using techniques like laser cap- and adult a- and b-cells. -
Prospective Isolation of NKX2-1–Expressing Human Lung Progenitors Derived from Pluripotent Stem Cells
The Journal of Clinical Investigation RESEARCH ARTICLE Prospective isolation of NKX2-1–expressing human lung progenitors derived from pluripotent stem cells Finn Hawkins,1,2 Philipp Kramer,3 Anjali Jacob,1,2 Ian Driver,4 Dylan C. Thomas,1 Katherine B. McCauley,1,2 Nicholas Skvir,1 Ana M. Crane,3 Anita A. Kurmann,1,5 Anthony N. Hollenberg,5 Sinead Nguyen,1 Brandon G. Wong,6 Ahmad S. Khalil,6,7 Sarah X.L. Huang,3,8 Susan Guttentag,9 Jason R. Rock,4 John M. Shannon,10 Brian R. Davis,3 and Darrell N. Kotton1,2 2 1Center for Regenerative Medicine, and The Pulmonary Center and Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, USA. 3Center for Stem Cell and Regenerative Medicine, Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center, Houston, Texas, USA. 4Department of Anatomy, UCSF, San Francisco, California, USA. 5Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA. 6Department of Biomedical Engineering and Biological Design Center, Boston University, Boston, Massachusetts, USA. 7Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts, USA. 8Columbia Center for Translational Immunology & Columbia Center for Human Development, Columbia University Medical Center, New York, New York, USA. 9Department of Pediatrics, Monroe Carell Jr. Children’s Hospital, Vanderbilt University, Nashville, Tennessee, USA. 10Division of Pulmonary Biology, Cincinnati Children’s Hospital, Cincinnati, Ohio, USA. It has been postulated that during human fetal development, all cells of the lung epithelium derive from embryonic, endodermal, NK2 homeobox 1–expressing (NKX2-1+) precursor cells. -
A Computational Approach for Defining a Signature of Β-Cell Golgi Stress in Diabetes Mellitus
Page 1 of 781 Diabetes A Computational Approach for Defining a Signature of β-Cell Golgi Stress in Diabetes Mellitus Robert N. Bone1,6,7, Olufunmilola Oyebamiji2, Sayali Talware2, Sharmila Selvaraj2, Preethi Krishnan3,6, Farooq Syed1,6,7, Huanmei Wu2, Carmella Evans-Molina 1,3,4,5,6,7,8* Departments of 1Pediatrics, 3Medicine, 4Anatomy, Cell Biology & Physiology, 5Biochemistry & Molecular Biology, the 6Center for Diabetes & Metabolic Diseases, and the 7Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202; 2Department of BioHealth Informatics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202; 8Roudebush VA Medical Center, Indianapolis, IN 46202. *Corresponding Author(s): Carmella Evans-Molina, MD, PhD ([email protected]) Indiana University School of Medicine, 635 Barnhill Drive, MS 2031A, Indianapolis, IN 46202, Telephone: (317) 274-4145, Fax (317) 274-4107 Running Title: Golgi Stress Response in Diabetes Word Count: 4358 Number of Figures: 6 Keywords: Golgi apparatus stress, Islets, β cell, Type 1 diabetes, Type 2 diabetes 1 Diabetes Publish Ahead of Print, published online August 20, 2020 Diabetes Page 2 of 781 ABSTRACT The Golgi apparatus (GA) is an important site of insulin processing and granule maturation, but whether GA organelle dysfunction and GA stress are present in the diabetic β-cell has not been tested. We utilized an informatics-based approach to develop a transcriptional signature of β-cell GA stress using existing RNA sequencing and microarray datasets generated using human islets from donors with diabetes and islets where type 1(T1D) and type 2 diabetes (T2D) had been modeled ex vivo. To narrow our results to GA-specific genes, we applied a filter set of 1,030 genes accepted as GA associated. -
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Supplementary Figure S1. Results of flow cytometry analysis, performed to estimate CD34 positivity, after immunomagnetic separation in two different experiments. As monoclonal antibody for labeling the sample, the fluorescein isothiocyanate (FITC)- conjugated mouse anti-human CD34 MoAb (Mylteni) was used. Briefly, cell samples were incubated in the presence of the indicated MoAbs, at the proper dilution, in PBS containing 5% FCS and 1% Fc receptor (FcR) blocking reagent (Miltenyi) for 30 min at 4 C. Cells were then washed twice, resuspended with PBS and analyzed by a Coulter Epics XL (Coulter Electronics Inc., Hialeah, FL, USA) flow cytometer. only use Non-commercial 1 Supplementary Table S1. Complete list of the datasets used in this study and their sources. GEO Total samples Geo selected GEO accession of used Platform Reference series in series samples samples GSM142565 GSM142566 GSM142567 GSM142568 GSE6146 HG-U133A 14 8 - GSM142569 GSM142571 GSM142572 GSM142574 GSM51391 GSM51392 GSE2666 HG-U133A 36 4 1 GSM51393 GSM51394 only GSM321583 GSE12803 HG-U133A 20 3 GSM321584 2 GSM321585 use Promyelocytes_1 Promyelocytes_2 Promyelocytes_3 Promyelocytes_4 HG-U133A 8 8 3 GSE64282 Promyelocytes_5 Promyelocytes_6 Promyelocytes_7 Promyelocytes_8 Non-commercial 2 Supplementary Table S2. Chromosomal regions up-regulated in CD34+ samples as identified by the LAP procedure with the two-class statistics coded in the PREDA R package and an FDR threshold of 0.5. Functional enrichment analysis has been performed using DAVID (http://david.abcc.ncifcrf.gov/) -
Genome-Wide DNA Methylation Analysis of KRAS Mutant Cell Lines Ben Yi Tew1,5, Joel K
www.nature.com/scientificreports OPEN Genome-wide DNA methylation analysis of KRAS mutant cell lines Ben Yi Tew1,5, Joel K. Durand2,5, Kirsten L. Bryant2, Tikvah K. Hayes2, Sen Peng3, Nhan L. Tran4, Gerald C. Gooden1, David N. Buckley1, Channing J. Der2, Albert S. Baldwin2 ✉ & Bodour Salhia1 ✉ Oncogenic RAS mutations are associated with DNA methylation changes that alter gene expression to drive cancer. Recent studies suggest that DNA methylation changes may be stochastic in nature, while other groups propose distinct signaling pathways responsible for aberrant methylation. Better understanding of DNA methylation events associated with oncogenic KRAS expression could enhance therapeutic approaches. Here we analyzed the basal CpG methylation of 11 KRAS-mutant and dependent pancreatic cancer cell lines and observed strikingly similar methylation patterns. KRAS knockdown resulted in unique methylation changes with limited overlap between each cell line. In KRAS-mutant Pa16C pancreatic cancer cells, while KRAS knockdown resulted in over 8,000 diferentially methylated (DM) CpGs, treatment with the ERK1/2-selective inhibitor SCH772984 showed less than 40 DM CpGs, suggesting that ERK is not a broadly active driver of KRAS-associated DNA methylation. KRAS G12V overexpression in an isogenic lung model reveals >50,600 DM CpGs compared to non-transformed controls. In lung and pancreatic cells, gene ontology analyses of DM promoters show an enrichment for genes involved in diferentiation and development. Taken all together, KRAS-mediated DNA methylation are stochastic and independent of canonical downstream efector signaling. These epigenetically altered genes associated with KRAS expression could represent potential therapeutic targets in KRAS-driven cancer. Activating KRAS mutations can be found in nearly 25 percent of all cancers1. -
A CRISPR-Based Screen for Hedgehog Signaling Provides Insights Into Ciliary Function and Ciliopathies
ARTICLES https://doi.org/10.1038/s41588-018-0054-7 A CRISPR-based screen for Hedgehog signaling provides insights into ciliary function and ciliopathies David K. Breslow 1,2,7*, Sascha Hoogendoorn 3,7, Adam R. Kopp2, David W. Morgens4, Brandon K. Vu2, Margaret C. Kennedy1, Kyuho Han4, Amy Li4, Gaelen T. Hess4, Michael C. Bassik4, James K. Chen 3,5* and Maxence V. Nachury 2,6* Primary cilia organize Hedgehog signaling and shape embryonic development, and their dysregulation is the unifying cause of ciliopathies. We conducted a functional genomic screen for Hedgehog signaling by engineering antibiotic-based selection of Hedgehog-responsive cells and applying genome-wide CRISPR-mediated gene disruption. The screen can robustly identify factors required for ciliary signaling with few false positives or false negatives. Characterization of hit genes uncovered novel components of several ciliary structures, including a protein complex that contains δ -tubulin and ε -tubulin and is required for centriole maintenance. The screen also provides an unbiased tool for classifying ciliopathies and showed that many congenital heart disorders are caused by loss of ciliary signaling. Collectively, our study enables a systematic analysis of ciliary function and of ciliopathies, and also defines a versatile platform for dissecting signaling pathways through CRISPR-based screening. he primary cilium is a surface-exposed microtubule-based approach. Indeed, most studies to date have searched for genes that compartment that serves as an organizing center for diverse either intrinsically affect cell growth or affect sensitivity to applied Tsignaling pathways1–3. Mutations affecting cilia cause ciliopa- perturbations16–23. thies, a group of developmental disorders including Joubert syn- Here, we engineered a Hh-pathway-sensitive reporter to enable drome, Meckel syndrome (MKS), nephronophthisis (NPHP), and an antibiotic-based selection platform. -
Fine-Scale Survey of X Chromosome Copy Number Variants and Indels Underlying Intellectual Disability
ARTICLE Fine-Scale Survey of X Chromosome Copy Number Variants and Indels Underlying Intellectual Disability Annabel C. Whibley,1 Vincent Plagnol,1,2 Patrick S. Tarpey,3 Fatima Abidi,4 Tod Fullston,5,6 Maja K. Choma,1 Catherine A. Boucher,1 Lorraine Shepherd,1 Lionel Willatt,7 Georgina Parkin,7 Raffaella Smith,3 P. Andrew Futreal,3 Marie Shaw,8 Jackie Boyle,9 Andrea Licata,4 Cindy Skinner,4 Roger E. Stevenson,4 Gillian Turner,9 Michael Field,9 Anna Hackett,9 Charles E. Schwartz,4 Jozef Gecz,5,6,8 Michael R. Stratton,3 and F. Lucy Raymond1,* Copy number variants and indels in 251 families with evidence of X-linked intellectual disability (XLID) were investigated by array comparative genomic hybridization on a high-density oligonucleotide X chromosome array platform. We identified pathogenic copy number variants in 10% of families, with mutations ranging from 2 kb to 11 Mb in size. The challenge of assessing causality was facilitated by prior knowledge of XLID-associated genes and the ability to test for cosegregation of variants with disease through extended pedigrees. Fine-scale analysis of rare variants in XLID families leads us to propose four additional genes, PTCHD1, WDR13, FAAH2, and GSPT2,as candidates for XLID causation and the identification of further deletions and duplications affecting X chromosome genes but without apparent disease consequences. Breakpoints of pathogenic variants were characterized to provide insight into the underlying mutational mechanisms and indicated a predominance of mitotic rather than meiotic events. By effectively bridging the gap between karyotype-level investigations and X chromosome exon resequencing, this study informs discussion of alternative mutational mechanisms, such as non- coding variants and non-X-linked disease, which might explain the shortfall of mutation yield in the well-characterized International Genetics of Learning Disability (IGOLD) cohort, where currently disease remains unexplained in two-thirds of families.