Euchromatic 16p+ heteromorphism: first report in North America

Am J Med Genet. 1990 Dec;37(4):548-50. doi: 10.1002/ajmg.1320370426.


A heteromorphism of the short arm of 16 (16p+) was discovered in 2 unrelated infants. By G banding, the euchromatic variant appears as a light and a medium dark band just distal to the centromere. This results in an increase of the short arm by about 1/3. The same variant was present in the normal father and the normal paternal grandmother in one family and mildly retarded mother in the 2nd family. The anomalies of the 2 infants are not similar and are apparently unrelated to the 16p+ variant. Though the discovery of such euchromatic variants is highly significant for clinical diagnosis, their genetic significance and mode of origin remain to be elucidated.

Publication types

  • Case Reports

MeSH terms

  • Abnormalities, Multiple / genetics*
  • Chromosome Aberrations*
  • Chromosome Banding
  • Chromosomes, Human, Pair 16*
  • Face / abnormalities*
  • Genetic Variation*
  • Growth Disorders / genetics
  • Heterochromatin / chemistry
  • Humans
  • Hypospadias / genetics
  • Infant
  • Male


  • Heterochromatin