De Novo Mutations in CHAMP1 Cause Intellectual Disability with Severe Speech Impairment.
CHAMP1 encodes a protein with a function in kinetochore-microtubule attachment and in the regulation of chromosome segregation, both of which are known to be important for neurodevelopment. By trio whole-exome sequencing, we have identified de novo deleterious mutations in CHAMP1 in five unrelated individuals affected by intellectual disability with severe speech impairment, motor developmental delay, muscular hypotonia, and similar dysmorphic features including short philtrum and a tented upper and everted lover lip. In addition to two frameshift and one nonsense mutations, we found an identical nonsense mutation, c.1192C>T (p.Arg398*), in two affected individuals. All mutations, if resulting in a stable protein, are predicted to lead to the loss of the functionally important zinc-finger domains in the C terminus of the protein, which regulate CHAMP1 localization to chromosomes and the mitotic spindle, thereby providing a mechanistic understanding for their pathogenicity. We thus establish deleterious de novo mutations in CHAMP1 as a cause of intellectual disability.
Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
Maja
M
Hempel
Institute of Human Genetics, University of Bonn, 53127 Bonn, Germany.
Kirsten
K
Cremer
Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands.
Charlotte W
CW
Ockeloen
Department of Medical Genetics, University Medical Center Utrecht, 3508 GA Utrecht, the Netherlands.
Klaske D
KD
Lichtenbelt
Department of Genetics, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, the Netherlands.
Johanna C
JC
Herkert
Department of Pediatrics, University Medical Center Eppendorf, 20246 Hamburg, Germany.
Jonas
J
Denecke
Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany.
Tobias B
TB
Haack
Institute of Human Genetics, University of Bonn, 53127 Bonn, Germany.
Alexander M
AM
Zink
Institute of Human Genetics, University of Bonn, 53127 Bonn, Germany.
Jessica
J
Becker
Institute of Human Genetics, University of Bonn, 53127 Bonn, Germany.
Eva
E
Wohlleber
Department of Pediatrics, University Medical Center Eppendorf, 20246 Hamburg, Germany.
Jessika
J
Johannsen
Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany.
Bader
B
Alhaddad
Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands.
Rolph
R
Pfundt
Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
Sigrid
S
Fuchs
Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, 45122 Essen, Germany.
Dagmar
D
Wieczorek
Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany.
Tim M
TM
Strom
Department of Medical Genetics, University Medical Center Utrecht, 3508 GA Utrecht, the Netherlands.
Koen L I
KL
van Gassen
Department of Human Genetics, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands.
Tjitske
T
Kleefstra
Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
Christian
C
Kubisch
Institute of Human Genetics, University of Bonn, 53127 Bonn, Germany. Electronic address: hartmut.engels@uni-bonn.de.
Hartmut
H
Engels
Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany. Electronic address: d.lessel@uke.de.
Davor
D
Lessel
D000015:Abnormalities, Multiple / Q000235:genetics* / Q000473:pathology*; D001483:Base Sequence; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics*; D018389:Codon, Nonsense / Q000235:genetics*; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013064:Speech Disorders / Q000235:genetics*
C555812:CHAMP1 protein, human; D002868:Chromosomal Proteins, Non-Histone; D018389:Codon, Nonsense; D010750:Phosphoproteins