Ring chromosome 12

Am J Med Genet. 1988 Feb;29(2):437-40. doi: 10.1002/ajmg.1320290228.


A ring chromosome 12 (p13.3q24.3) was observed in all cells analyzed from skin fibroblasts and the peripheral blood of a 19-year-old man initially referred for developmental delay with expressive language deficiency. Other phenotypic anomalies included growth deficiency, multiple café-au-lait spots, mild pectus excavatum, glandular hypospadias, left esotropia, clinodactyly of the fifth fingers, and hypothyroidism with elevated antithyroid antibodies. The four previously reported cases of r(12) support the theory of a general ring phenotype which is manifested independently of the specific autosome involved and which is characterized by growth failure, moderate mental retardation, and lack of other major phenotypic anomalies. Breakpoints in all cases of r(12) have been assigned to the telomeric regions, suggesting minimal deletion of chromosome material.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Chromosome Aberrations*
  • Chromosomes, Human, Pair 12*
  • Growth Disorders / genetics*
  • Humans
  • Intellectual Disability / genetics*
  • Male
  • Pigmentation Disorders / genetics
  • Ring Chromosomes*