title: A new small supernumerary marker chromosome involving 14pter → q12 in a child with severe neurodevelopmental retardation: case report and literature review.
abstract: Unstable, gene-rich pericentric regions have been associated with various structural aberrations including small supernumerary marker chromosomes (sSMCs). We hereby report on a new sSMC derived from chromosome 14, generating trisomy 14pter → q12 in a child with severe neurodevelopmental delay. The patient featured facial dysmorphism, generalized hypotonia, transverse palmar creases, structural brain abnormality, and severe cognitive and motor impairment. Literature review indicated this to be a unique case of sSMC 14 which was only composed of pter → q12, and the phenotype secondary to duplications of the similar region partially overlaps with the phenotype reported in this study. The genetic analysis on our case helps to better delineate karyotype-phenotype correlations between proximal trisomy 14 and associated clinical phenomena, and we also propose that the involved chromosomal regions may contain dosage-sensitive genes which are important for the development.
authors.affiliation: Department of Clinical Genetics, the Affiliated Shengjing Hospital, China Medical University, Shenyang, Liaoning Province 110004, China. Electronic address: 2005fyuan@sina.com.
authors.forename: Manlong
authors.initials: M
authors.lastname: Qi
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yueping
authors.initials: Y
authors.lastname: Wang
authors.forename: Tingting
authors.initials: T
authors.lastname: Li
mesh_terms: D002675:Child, Preschool; D002869:Chromosome Aberrations; D002883:Chromosomes, Human, Pair 14 / Q000235:genetics*; D005819:Genetic Markers; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D012720:Severity of Illness Index; D014314:Trisomy / Q000235:genetics*
chemical_list: D005819:Genetic Markers
keywords: CHD8; CNV; COCH; Chromosome 14 marker; FISH; FOXG1; G2/M-phase specific E3 ubiquitin protein ligase; G2E3; Karyotype–phenotype; MRI; Mental retardation; NOVA1; PRKD1; SUPT16H; Supernumerary marker chromosome; TOX high mobility group box family member 4; TOX4; chromodomain helicase DNA binding protein 8; coagulation factor C homolog, cochlin (Limulus polyphemus); copy number variation; fluorescent in situ hybridization; forkhead box G1; magnetic resonance imaging; neuro-oncological ventral antigen 1; protein kinase D1; sSMC; small supernumerary marker chromosome; suppressor of Ty 16 homolog (S. cerevisiae)