CNTNAP2 and NRXN1 are mutated in autosomal-recessive Pitt-Hopkins-like mental retardation and determine the level of a common synaptic protein in Drosophila

Christiane Zweier, Eiko K de Jong, Markus Zweier, Alfredo Orrico, Lilian B Ousager, Amanda L Collins, Emilia K Bijlsma, Merel A W Oortveld, Arif B Ekici, André Reis, Annette Schenck, Anita Rauch

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Abstract

Heterozygous copy-number variants and SNPs of CNTNAP2 and NRXN1, two distantly related members of the neurexin superfamily, have been repeatedly associated with a wide spectrum of neuropsychiatric disorders, such as developmental language disorders, autism spectrum disorders, epilepsy, and schizophrenia. We now identified homozygous and compound-heterozygous deletions and mutations via molecular karyotyping and mutational screening in CNTNAP2 and NRXN1 in four patients with severe mental retardation (MR) and variable features, such as autistic behavior, epilepsy, and breathing anomalies, phenotypically overlapping with Pitt-Hopkins syndrome. With a frequency of at least 1% in our cohort of 179 patients, recessive defects in CNTNAP2 appear to significantly contribute to severe MR. Whereas the established synaptic role of NRXN1 suggests that synaptic defects contribute to the associated neuropsychiatric disorders and to severe MR as reported here, evidence for a synaptic role of the CNTNAP2-encoded protein CASPR2 has so far been lacking. Using Drosophila as a model, we now show that, as known for fly Nrx-I, the CASPR2 ortholog Nrx-IV might also localize to synapses. Overexpression of either protein can reorganize synaptic morphology and induce increased density of active zones, the synaptic domains of neurotransmitter release. Moreover, both Nrx-I and Nrx-IV determine the level of the presynaptic active-zone protein bruchpilot, indicating a possible common molecular mechanism in Nrx-I and Nrx-IV mutant conditions. We therefore propose that an analogous shared synaptic mechanism contributes to the similar clinical phenotypes resulting from defects in human NRXN1 and CNTNAP2.
Original languageEnglish
JournalAmerican Journal of Human Genetics
Volume85
Issue number5
Pages (from-to)655-66
Number of pages11
ISSN0002-9297
DOIs
Publication statusPublished - 1. Nov 2009

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Language Development Disorders
Proteins
Single Nucleotide Polymorphism
Neurotransmitter Agents
Respiration
Autism Spectrum Disorder

Cite this

Zweier, Christiane ; de Jong, Eiko K ; Zweier, Markus ; Orrico, Alfredo ; Ousager, Lilian B ; Collins, Amanda L ; Bijlsma, Emilia K ; Oortveld, Merel A W ; Ekici, Arif B ; Reis, André ; Schenck, Annette ; Rauch, Anita. / CNTNAP2 and NRXN1 are mutated in autosomal-recessive Pitt-Hopkins-like mental retardation and determine the level of a common synaptic protein in Drosophila. In: American Journal of Human Genetics. 2009 ; Vol. 85, No. 5. pp. 655-66.
@article{2e0350b0dd8d11deb0fe000ea68e967b,
title = "CNTNAP2 and NRXN1 are mutated in autosomal-recessive Pitt-Hopkins-like mental retardation and determine the level of a common synaptic protein in Drosophila",
abstract = "Heterozygous copy-number variants and SNPs of CNTNAP2 and NRXN1, two distantly related members of the neurexin superfamily, have been repeatedly associated with a wide spectrum of neuropsychiatric disorders, such as developmental language disorders, autism spectrum disorders, epilepsy, and schizophrenia. We now identified homozygous and compound-heterozygous deletions and mutations via molecular karyotyping and mutational screening in CNTNAP2 and NRXN1 in four patients with severe mental retardation (MR) and variable features, such as autistic behavior, epilepsy, and breathing anomalies, phenotypically overlapping with Pitt-Hopkins syndrome. With a frequency of at least 1{\%} in our cohort of 179 patients, recessive defects in CNTNAP2 appear to significantly contribute to severe MR. Whereas the established synaptic role of NRXN1 suggests that synaptic defects contribute to the associated neuropsychiatric disorders and to severe MR as reported here, evidence for a synaptic role of the CNTNAP2-encoded protein CASPR2 has so far been lacking. Using Drosophila as a model, we now show that, as known for fly Nrx-I, the CASPR2 ortholog Nrx-IV might also localize to synapses. Overexpression of either protein can reorganize synaptic morphology and induce increased density of active zones, the synaptic domains of neurotransmitter release. Moreover, both Nrx-I and Nrx-IV determine the level of the presynaptic active-zone protein bruchpilot, indicating a possible common molecular mechanism in Nrx-I and Nrx-IV mutant conditions. We therefore propose that an analogous shared synaptic mechanism contributes to the similar clinical phenotypes resulting from defects in human NRXN1 and CNTNAP2.",
author = "Christiane Zweier and {de Jong}, {Eiko K} and Markus Zweier and Alfredo Orrico and Ousager, {Lilian B} and Collins, {Amanda L} and Bijlsma, {Emilia K} and Oortveld, {Merel A W} and Ekici, {Arif B} and Andr{\'e} Reis and Annette Schenck and Anita Rauch",
year = "2009",
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Zweier, C, de Jong, EK, Zweier, M, Orrico, A, Ousager, LB, Collins, AL, Bijlsma, EK, Oortveld, MAW, Ekici, AB, Reis, A, Schenck, A & Rauch, A 2009, 'CNTNAP2 and NRXN1 are mutated in autosomal-recessive Pitt-Hopkins-like mental retardation and determine the level of a common synaptic protein in Drosophila', American Journal of Human Genetics, vol. 85, no. 5, pp. 655-66. https://doi.org/10.1016/j.ajhg.2009.10.004

CNTNAP2 and NRXN1 are mutated in autosomal-recessive Pitt-Hopkins-like mental retardation and determine the level of a common synaptic protein in Drosophila. / Zweier, Christiane; de Jong, Eiko K; Zweier, Markus; Orrico, Alfredo; Ousager, Lilian B; Collins, Amanda L; Bijlsma, Emilia K; Oortveld, Merel A W; Ekici, Arif B; Reis, André; Schenck, Annette; Rauch, Anita.

In: American Journal of Human Genetics, Vol. 85, No. 5, 01.11.2009, p. 655-66.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - CNTNAP2 and NRXN1 are mutated in autosomal-recessive Pitt-Hopkins-like mental retardation and determine the level of a common synaptic protein in Drosophila

AU - Zweier, Christiane

AU - de Jong, Eiko K

AU - Zweier, Markus

AU - Orrico, Alfredo

AU - Ousager, Lilian B

AU - Collins, Amanda L

AU - Bijlsma, Emilia K

AU - Oortveld, Merel A W

AU - Ekici, Arif B

AU - Reis, André

AU - Schenck, Annette

AU - Rauch, Anita

PY - 2009/11/1

Y1 - 2009/11/1

N2 - Heterozygous copy-number variants and SNPs of CNTNAP2 and NRXN1, two distantly related members of the neurexin superfamily, have been repeatedly associated with a wide spectrum of neuropsychiatric disorders, such as developmental language disorders, autism spectrum disorders, epilepsy, and schizophrenia. We now identified homozygous and compound-heterozygous deletions and mutations via molecular karyotyping and mutational screening in CNTNAP2 and NRXN1 in four patients with severe mental retardation (MR) and variable features, such as autistic behavior, epilepsy, and breathing anomalies, phenotypically overlapping with Pitt-Hopkins syndrome. With a frequency of at least 1% in our cohort of 179 patients, recessive defects in CNTNAP2 appear to significantly contribute to severe MR. Whereas the established synaptic role of NRXN1 suggests that synaptic defects contribute to the associated neuropsychiatric disorders and to severe MR as reported here, evidence for a synaptic role of the CNTNAP2-encoded protein CASPR2 has so far been lacking. Using Drosophila as a model, we now show that, as known for fly Nrx-I, the CASPR2 ortholog Nrx-IV might also localize to synapses. Overexpression of either protein can reorganize synaptic morphology and induce increased density of active zones, the synaptic domains of neurotransmitter release. Moreover, both Nrx-I and Nrx-IV determine the level of the presynaptic active-zone protein bruchpilot, indicating a possible common molecular mechanism in Nrx-I and Nrx-IV mutant conditions. We therefore propose that an analogous shared synaptic mechanism contributes to the similar clinical phenotypes resulting from defects in human NRXN1 and CNTNAP2.

AB - Heterozygous copy-number variants and SNPs of CNTNAP2 and NRXN1, two distantly related members of the neurexin superfamily, have been repeatedly associated with a wide spectrum of neuropsychiatric disorders, such as developmental language disorders, autism spectrum disorders, epilepsy, and schizophrenia. We now identified homozygous and compound-heterozygous deletions and mutations via molecular karyotyping and mutational screening in CNTNAP2 and NRXN1 in four patients with severe mental retardation (MR) and variable features, such as autistic behavior, epilepsy, and breathing anomalies, phenotypically overlapping with Pitt-Hopkins syndrome. With a frequency of at least 1% in our cohort of 179 patients, recessive defects in CNTNAP2 appear to significantly contribute to severe MR. Whereas the established synaptic role of NRXN1 suggests that synaptic defects contribute to the associated neuropsychiatric disorders and to severe MR as reported here, evidence for a synaptic role of the CNTNAP2-encoded protein CASPR2 has so far been lacking. Using Drosophila as a model, we now show that, as known for fly Nrx-I, the CASPR2 ortholog Nrx-IV might also localize to synapses. Overexpression of either protein can reorganize synaptic morphology and induce increased density of active zones, the synaptic domains of neurotransmitter release. Moreover, both Nrx-I and Nrx-IV determine the level of the presynaptic active-zone protein bruchpilot, indicating a possible common molecular mechanism in Nrx-I and Nrx-IV mutant conditions. We therefore propose that an analogous shared synaptic mechanism contributes to the similar clinical phenotypes resulting from defects in human NRXN1 and CNTNAP2.

U2 - 10.1016/j.ajhg.2009.10.004

DO - 10.1016/j.ajhg.2009.10.004

M3 - Journal article

C2 - 19896112

VL - 85

SP - 655

EP - 666

JO - American Journal of Human Genetics

JF - American Journal of Human Genetics

SN - 0002-9297

IS - 5

ER -