title: Heterozygous deletion of CHL1 gene: detailed array-CGH and clinical  characterization of a new case and review of the literature.
abstract: CHL1 gene maps at 3p26.3 and encodes a cell adhesion molecule of the immunoglobulin superfamily highly expressed in the brain. CHL1 regulates neuronal migration and neurite overgrowth in the developing brain, while in mature neurons it accumulates in the axonal membrane and regulates synapse function via the clathrin-dependent pathways. To our knowledge, to date only three familial cases presenting heterozygous deletion of chromosome 3 at band p26.3, including only the CHL1 gene, have been reported. All the patients presented cognitive impairment characterized by learning and language difficulties. Here, we describe a six-year-old boy in which array-CGH analysis disclosed a terminal 3p26.3 deletion. The deletion was transmitted from his normal mother and included only the CHL1 gene. Our patient presented microcephaly, short stature, mild mental retardation, learning and language delay, and strabismus. In our study we compare the phenotypic and molecular cytogenetic features of CHL1 gene deletion cases. Verbal function developmental delay seems to be a common key finding. The concomitance of the genetic and phenotypic alterations could be a good evidence of a new emerging syndrome associated with the deletion of CHL1 gene alone, although the identification of new cases is required.
authors.forename: Elisa
authors.initials: E
authors.lastname: Tassano
authors.forename: Roberta
authors.initials: R
authors.lastname: Biancheri
authors.forename: Laura
authors.initials: L
authors.lastname: Denegri
authors.forename: Simona
authors.initials: S
authors.lastname: Porta
authors.forename: Francesca
authors.initials: F
authors.lastname: Novara
authors.forename: Orsetta
authors.initials: O
authors.lastname: Zuffardi
authors.forename: Giorgio
authors.initials: G
authors.lastname: Gimelli
authors.forename: Cristina
authors.initials: C
authors.lastname: Cuoco
mesh_terms: D015815:Cell Adhesion Molecules / Q000235:genetics*; D002648:Child; D055028:Comparative Genomic Hybridization; D017353:Gene Deletion; D056726:Genetic Association Studies; D006579:Heterozygote; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis* / Q000235:genetics; D059785:Karyotype; D008297:Male
chemical_list: C490650:CHL1 protein, human; D015815:Cell Adhesion Molecules