Abstract
BackgroundDetection of submicroscopic chromosomal alterations in patients with a idiopathic intellectual disability (ID) allows significant improvement in delineation of the regions of the genome that are associated with brain development and function. However, these chromosomal regions usually contain several protein-coding genes and regulatory elements, complicating the understanding of genotype-phenotype correlations. We report two siblings with ID and an unrelated patient with atypical autism who had 3p26.3 microdeletions and one intellectually disabled patient with a 3p26.3 microduplication encompassing only the CNTN6 gene.ResultsTwo 295.1-kb microdeletions and one 766.1-kb microduplication of 3p26.3 involving a single gene, CNTN6, were identified with an Agilent 60K array. Another 271.9-kb microdeletion of 3p26.3 was detected using an Affymetrix CytoScan HD chromosome microarray platform. The CHL1 and CNTN4 genes, although adjacent to the CNTN6 gene, were not affected in either of these patients.ConclusionsThe protein encoded by CNTN6 is a member of the immunoglobulin superfamily and functions as a cell adhesion molecule that is involved in the formation of axon connections in the developing nervous system. Our results indicate that CNTN6 may be a candidate gene for ID.Electronic supplementary materialThe online version of this article (doi:10.1186/s13039-014-0097-0) contains supplementary material, which is available to authorized users.
Highlights
Detection of submicroscopic chromosomal alterations in patients with a idiopathic intellectual disability (ID) allows significant improvement in delineation of the regions of the genome that are associated with brain development and function
We report for the first time two siblings with 295.1-kb microdeletions, an unrelated patient with a 271.9-kb microdeletion and an additional patient with a 766.1-kb microduplication of 3p26.3, all of which encompass a single gene, Contactin 6 (CNTN6)
The CNTN6 gene is located in the region which includes several more genes (CNTN4, CRBN, Cell adhesion molecule L1-like (CHL1)) involved in the clinical picture of the distal 3p deletion syndrome [16]
Summary
Detection of submicroscopic chromosomal alterations in patients with a idiopathic intellectual disability (ID) allows significant improvement in delineation of the regions of the genome that are associated with brain development and function. These chromosomal regions usually contain several protein-coding genes and regulatory elements, complicating the understanding of genotype-phenotype correlations. Most chromosomal microdeletions and microduplications encompass several genes with various functions, creating a challenge in understanding genotype-phenotype correlations These mutations may involve a single gene or a portion of a gene, blurring the border between chromosomal and monogenic diseases [1,2]. Analysis of microdeletions and microduplications affecting this gene may be of particular relevance for the distal 3p deletion syndrome
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
