title: Chromosome 5 derived small supernumerary marker: towards a genotype/phenotype correlation of proximal chromosome 5 imbalances.
abstract: Small supernumerary marker chromosomes (sSMC) are a morphological heterogeneous group of additional abnormal chromosomes that cannot be characterized alone by conventional banding cytogenetics. Molecular cytogenetic techniques are valuable tools for the accurate identification of sSMC and a prerequisite for sound genetic counseling based on refined genotype/phenotype correlation. We describe a new case of a retarded patient with an sSMC derived from chromosome 5. The characterization of the sSMC was done by subcentromere-specific multicolor (subcenM) fluorescence in-situ hybridization (FISH) and by full tilling resolution array analysis, after microdissection and amplification of the marker DNA. Uniparental disomy for normal sister chromosomes of the sSMC(5) was excluded. The karyotype was mos47,XX,+r(5)(::p11.1 → q12.1::)[70%]/46,XX[30%], being the trisomic region between 46.15 ∼ 49.56 Mb and 61.25 ∼ 61.335 Mb, a region known to harbor ∼45 annotated genes. Together with a review of the previously described cases of sSMC(5) and duplications involving the 5q proximal region, we can conclude that trisomy of the 5q11 region is associated with learning difficulties and speech delay.
authors: Laboratório de Citogenética e Genómica, Centro de Neurociências e Biologia Celular, Faculty of Medicine, University of Coimbra, 3000-354, Coimbra, Portugal. mmelo@fmed.uc.pt
authors: Joana Barbosa
authors: JB
authors: Melo
authors: Liesbeth
authors: L
authors: Backx
authors: Joris R
authors: JR
authors: Vermeesch
authors: Heloisa G
authors: HG
authors: Santos
authors: Ana C
authors: AC
authors: Sousa
authors: Nadezda
authors: N
authors: Kosyakova
authors: Anja
authors: A
authors: Weise
authors: Ferdinand
authors: F
authors: von Eggeling
authors: Thomas
authors: T
authors: Liehr
authors: Isabel Marques
authors: IM
authors: Carreira
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics; D000328:Adult; D002869:Chromosome Aberrations; D058674:Chromosome Duplication; D002895:Chromosomes, Human, Pair 5 / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D019465:Craniofacial Abnormalities / Q000235:genetics; D005260:Female; D056726:Genetic Association Studies; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008607:Intellectual Disability / Q000235:genetics; D007805:Language Development Disorders / Q000235:genetics; D014314:Trisomy