title: 18q deletions: clinical, molecular, and brain MRI findings of 14 individuals.
abstract: We studied 14 individuals with partial deletions of the long arm of chromosome 18, including terminal and interstitial de novo and inherited deletions. Study participants were examined clinically and by brain MRI. The size of the deletion was determined by segregation analysis using microsatellite markers. We observed that the phenotype was highly variable, even in two families with three 1st degree relatives. Among the 14 individuals, general intelligence varied from normal to severe mental retardation. The more common features of 18q-deletions (e.g., foot deformities, aural atresia, palatal abnormalities, dysmyelination, and nystagmus) were present in individuals lacking only the distal portion 18q22.3-qtel. Interstitial deletions exerted very heterogeneous effects on phenotype. In individuals with distal 18q22.3-q23 deletions, brain MRI was very distinctive with poor differentiation of gray and white matter on T2-weighted images.
authors.affiliation: Department of Pediatric Neurology, Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland. tarja.linnankivi@kolumbus.fi
authors.forename: Tarja
authors.initials: T
authors.lastname: Linnankivi
authors.forename: Pentti
authors.initials: P
authors.lastname: Tienari
authors.forename: Mirja
authors.initials: M
authors.lastname: Somer
authors.forename: Marketta
authors.initials: M
authors.lastname: Kähkönen
authors.forename: Tuula
authors.initials: T
authors.lastname: Lönnqvist
authors.forename: Leena
authors.initials: L
authors.lastname: Valanne
authors.forename: Helena
authors.initials: H
authors.lastname: Pihko
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D001921:Brain / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D020090:Chromosome Segregation; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D005260:Female; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000235:genetics; D008279:Magnetic Resonance Imaging; D008297:Male; D018895:Microsatellite Repeats; D004676:Myelin Basic Protein / Q000235:genetics; D010641:Phenotype
chemical_list: D004676:Myelin Basic Protein