Ring chromosome 8 syndrome

What is Ring chromosome 8 syndrome?

Chromosome 8-derived supernumerary ring/marker is a rare chromosomal anomaly comprising variable parts of chromosome 8. The phenotype of mosaic or non-mosaic supernumerary r(8)/mar(8) ranges from almost normal to variable degrees of minor abnormalities, and growth and mental retardation overlapping with the well-known mosaic trisomy 8 syndrome (see this term).

Other condition names

  • Ring 8
  • Ring chromosome 8
  • r(8) syndrome


  • Worldwide: <1 in 1,000 000

Age of Onset

  • Neonatal
Orphadata: Free access data from Orphanet. © INSERM 1999. Available on "https://www.orphadata.com". Data version 1.3.16 / 4.1.7.