A new small supernumerary marker chromosome involving 14pter → q12 in a child with severe neurodevelopmental retardation: case report and literature review

Gene. 2013 Dec 1;531(2):457-61. doi: 10.1016/j.gene.2013.08.084. Epub 2013 Sep 5.


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.

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).

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Child, Preschool
  • Chromosome Aberrations
  • Chromosomes, Human, Pair 14 / genetics*
  • Genetic Markers
  • Humans
  • Intellectual Disability / diagnosis
  • Intellectual Disability / genetics*
  • Male
  • Severity of Illness Index
  • Trisomy / genetics*


  • Genetic Markers

Supplementary concepts

  • Chromosome 14 trisomy