title: Delineation of a critical region on chromosome 18 for the del(18)(q12.2q21.1) syndrome.
abstract: Deletions involving the long arm of chromosome 18 have been reported in many patients. Most of these deletions are localized in the distal half of the long arm (18q21.1 --> qter) and are detectable by standard cytogenetic analysis. However, smaller interstitial deletions leading to a recognizable phenotype and residing in the region around chromosome band 18q12.3 (bands q12-q21) are less common. Here we report on an interstitial deletion of less than 1.8 Mb within chromosomal band 18q12.3. The phenotypic features of the propositus correspond well with those observed in patients with larger cytogenetically detectable deletions encompassing chromosome band 18q12.3. The deletion enabled us to define a critical region for the following features of the del(18)(q12.2q21.1) syndrome: hypotonia, expressive language delay, short stature, and behavioral problems.
authors.affiliation: Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium.
authors.forename: Karen
authors.initials: K
authors.lastname: Buysse
authors.forename: Björn
authors.initials: B
authors.lastname: Menten
authors.forename: Ann
authors.initials: A
authors.lastname: Oostra
authors.forename: Sylvie
authors.initials: S
authors.lastname: Tavernier
authors.forename: Geert R
authors.initials: GR
authors.lastname: Mortier
authors.forename: Frank
authors.initials: F
authors.lastname: Speleman
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics* / Q000503:physiopathology; D001526:Behavioral Symptoms / Q000235:genetics*; D002648:Child; D002869:Chromosome Aberrations; D002872:Chromosome Deletion; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D006130:Growth Disorders / Q000235:genetics*; D006801:Humans; D007805:Language Development Disorders / Q000235:genetics*; D008297:Male; D009123:Muscle Hypotonia / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D013577:Syndrome