18q deletions: Clinical, molecular, and brain MRI findings of 14 individuals

• Published in: American journal of medical genetics. Part A Vol. 140A; no. 4; pp. 331 - 339
• Main Authors: Linnankivi, Tarja, Tienari, Pentti, Somer, Mirja, Kähkönen, Marketta, Lönnqvist, Tuula, Valanne, Leena, Pihko, Helena
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15-02-2006; Wiley-Liss
• Subjects: 18q-deletion; Abnormalities, Multiple - genetics; Abnormalities, Multiple - pathology; Adolescent; Adult; aural atresia; Biological and medical sciences; Brain - pathology; Child; Child, Preschool; Chromosome Deletion; Chromosome Segregation; Chromosomes, Human, Pair 18 - genetics; dysmyelination; Female; Humans; Infant; Intellectual Disability - genetics; Magnetic Resonance Imaging; Male; Medical genetics; Medical sciences; Microsatellite Repeats; myelin basic protein; Myelin Basic Protein - genetics; Phenotype; Chromosomal aberration; Human; aural atresia; Myelin; 18q-deletion; myelin basic protein; Nuclear magnetic resonance imaging; Encephalon; Symptomatology; Chromosome E18; Phenotype; Basic protein; Atresia; Deletion; Medical imagery; dysmyelination
• ISSN: 1552-4825; 1552-4833
• DOI: 10.1002/ajmg.a.31072

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. © 2006 Wiley‐Liss, Inc.