FISH and array-CGH analysis of a complex chromosome 3 aberration suggests that loss of CNTN4 and CRBN contributes to mental retardation in 3pter deletions.
Imbalances of 3p telomeric sequences cause 3p- and trisomy 3p syndrome, respectively, showing distinct, but also shared clinical features. No causative genes have been identified in trisomy 3p patients, but for the 3p- syndrome, there is growing evidence that monosomy for one or more of four genes at 3pter, CHL1, CNTN4, CRBN, and MEGAP/srGAP3, may play a causative role. We describe here an analysis of a complex chromosome 3p aberration in a severely mentally retarded patient that revealed two adjacent segments with different copy number gains and a distal deletion. The deletion in this patient included the loci for CHL1, CNTN4, and CRBN, and narrowed the critical segment associated with the 3p- syndrome to 1.5 Mb, including the loci for CNTN4 and CRBN. We speculate that the deletion contributes more to this patient's phenotype than the gains that were observed. We suggest that 3p- syndrome associated features are primarily caused by loss of CNTN4 and CRBN, with loss of CHL1 probably having an additional detrimental effect on the cognitive functioning of the present patient.
Dijkhuizen
Trijnie
T
Department of Clinical Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. T.Dijkhuizen@medgen.umcg.nl
van Essen
Ton
T
van der Vlies
Pieter
P
Verheij
Joke B G M
JB
Sikkema-Raddatz
Birgit
B
van der Veen
Anneke Y
AY
Gerssen-Schoorl
Klasien B J
KB
Buys
Charles H C M
CH
Kok
Klaas
K
D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics*; D002869:Chromosome Aberrations; D002872:Chromosome Deletion; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics*; D058966:Contactins; D003582:Cytogenetics; D005260:Female; D018628:Gene Dosage; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008607:Intellectual Disability / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010447:Peptide Hydrolases / Q000235:genetics*; D010641:Phenotype; D044767:Ubiquitin-Protein Ligases
D048868:Adaptor Proteins, Signal Transducing; C490650:CHL1 protein, human; C098304:CNTN4 protein, human; C502543:CRBN protein, human; D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal; D058966:Contactins; D008565:Membrane Proteins; D044767:Ubiquitin-Protein Ligases; D010447:Peptide Hydrolases