title: Identification and Functional Characterization of Two Intronic NIPBL Mutations in Two Patients with Cornelia de Lange Syndrome.
abstract: Cornelia de Lange syndrome (CdLS) is a rare genetically heterogeneous disorder with a high phenotypic variability including mental retardation, developmental delay, and limb malformations. The genetic causes in about 30% of patients with CdLS are still unknown. We report on the functional characterization of two intronic NIPBL mutations in two patients with CdLS that do not affect a conserved splice-donor or acceptor site. Interestingly, mRNA analyses showed aberrantly spliced transcripts missing exon 28 or 37, suggesting the loss of the branch site by the c.5329-15A>G transition and a disruption of the polypyrimidine by the c.6344del(-13)_(-8) deletion. While the loss of exon 28 retains the reading frame of the NIBPL transcript resulting in a shortened protein, the loss of exon 37 shifts the reading frame with the consequence of a premature stop of translation. Subsequent quantitative PCR analysis demonstrated a 30% decrease of the total NIPBL mRNA levels associated with the frameshift transcript. Consistent with our results, this patient shows a more severe phenotype compared to the patient with the aberrant transcript that retains its reading frame. Thus, intronic variants identified by sequencing analysis in CdLS diagnostics should carefully be examined before excluding them as nonrelevant to disease.
authors.affiliation: Unit of Clinical Genetics and Functional Genomics, Departments of Pharmacology-Physiology and Pediatrics, School of Medicine, University of Zaragoza, CIBERER-GCV and ISS-Aragon, 50009 Zaragoza, Spain.
authors.forename: María E
authors.initials: ME
authors.lastname: Teresa-Rodrigo
authors.affiliation: Section of Functional Genetics, Institute of Human Genetics, University of Lübeck, 23538 Lübeck, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Eckhold
authors.affiliation: Unit of Clinical Genetics and Functional Genomics, Departments of Pharmacology-Physiology and Pediatrics, School of Medicine, University of Zaragoza, CIBERER-GCV and ISS-Aragon, 50009 Zaragoza, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Puisac
authors.affiliation: Section of Functional Genetics, Institute of Human Genetics, University of Lübeck, 23538 Lübeck, Germany.
authors.forename: Jelena
authors.initials: J
authors.lastname: Pozojevic
authors.affiliation: Section of Functional Genetics, Institute of Human Genetics, University of Lübeck, 23538 Lübeck, Germany; Department of Health Sciences, Medical Genetics, University of Milan, 20122 Milan, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Parenti
authors.affiliation: Unit of Clinical Genetics and Functional Genomics, Departments of Pharmacology-Physiology and Pediatrics, School of Medicine, University of Zaragoza, CIBERER-GCV and ISS-Aragon, 50009 Zaragoza, Spain; Department of Pediatrics, Pablo Tobon Uribe Hospital, 05001000 Medellín, Colombia.
authors.forename: Carolina
authors.initials: C
authors.lastname: Baquero-Montoya
authors.affiliation: Unit of Clinical Genetics and Functional Genomics, Departments of Pharmacology-Physiology and Pediatrics, School of Medicine, University of Zaragoza, CIBERER-GCV and ISS-Aragon, 50009 Zaragoza, Spain.
authors.forename: María C
authors.initials: MC
authors.lastname: Gil-Rodríguez
authors.affiliation: Section of Functional Genetics, Institute of Human Genetics, University of Lübeck, 23538 Lübeck, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Braunholz
authors.affiliation: Institute of Human Genetics, University of Lübeck, 23538 Lübeck, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Dalski
authors.affiliation: Unit of Clinical Genetics and Functional Genomics, Departments of Pharmacology-Physiology and Pediatrics, School of Medicine, University of Zaragoza, CIBERER-GCV and ISS-Aragon, 50009 Zaragoza, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Hernández-Marcos
authors.affiliation: Unit of Clinical Genetics and Functional Genomics, Departments of Pharmacology-Physiology and Pediatrics, School of Medicine, University of Zaragoza, CIBERER-GCV and ISS-Aragon, 50009 Zaragoza, Spain.
authors.forename: Ariadna
authors.initials: A
authors.lastname: Ayerza
authors.affiliation: Unit of Clinical Genetics and Functional Genomics, Departments of Pharmacology-Physiology and Pediatrics, School of Medicine, University of Zaragoza, CIBERER-GCV and ISS-Aragon, 50009 Zaragoza, Spain.
authors.forename: María L
authors.initials: ML
authors.lastname: Bernal
authors.affiliation: Unit of Clinical Genetics and Functional Genomics, Departments of Pharmacology-Physiology and Pediatrics, School of Medicine, University of Zaragoza, CIBERER-GCV and ISS-Aragon, 50009 Zaragoza, Spain.
authors.forename: Feliciano J
authors.initials: FJ
authors.lastname: Ramos
authors.affiliation: Institute of Human Genetics, University Hospital Düsseldorf, Heinrich-Heine University, 40225 Düsseldorf, Germany.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Wieczorek
authors.affiliation: Institute of Human Genetics, University of Lübeck, 23538 Lübeck, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Gillessen-Kaesbach
authors.affiliation: Unit of Clinical Genetics and Functional Genomics, Departments of Pharmacology-Physiology and Pediatrics, School of Medicine, University of Zaragoza, CIBERER-GCV and ISS-Aragon, 50009 Zaragoza, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Pié
authors.affiliation: Section of Functional Genetics, Institute of Human Genetics, University of Lübeck, 23538 Lübeck, Germany.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Kaiser
mesh_terms: D018797:Cell Cycle Proteins; D002648:Child; D003635:De Lange Syndrome / Q000235:genetics* / Q000473:pathology; D005091:Exons; D005260:Female; D016368:Frameshift Mutation / Q000235:genetics; D018740:Genetic Heterogeneity; D056945:Hep G2 Cells; D006801:Humans; D007438:Introns; D008297:Male; D010375:Pedigree; D011506:Proteins / Q000235:genetics*; D012326:RNA Splicing / Q000235:genetics
chemical_list: D018797:Cell Cycle Proteins; C487465:NIPBL protein, human; D011506:Proteins