Partial trisomy of the short arm of chromosome 18 due to inversion duplication and direct duplication

Clin Genet. 1994 Dec;46(6):423-9. doi: 10.1111/j.1399-0004.1994.tb04410.x.


We report one patient with a de novo inversion duplication 18 (pter-->cen) and two cases of direct tandem duplication 18 (pter-->cen), one due to maternal inheritance and the other arising as mosaicism of unknown origin. The duplications are demonstrated by high resolution banding. They were verified by in situ hybridization with a paint specific for chromosome 18 and with DNA probe LI.84 specific for the centromere region of chromosome 18. FISH with the genomic DNA probe pHRR68 specific for 18p11.32 revealed a subtle deletion concomitantly involved in the case of inversion duplication 18p. The patients exhibit slight developmental delay/moderate mental retardation and only a few dysmorphic features. The literature on trisomy 18p is reviewed and the present cases are compared to it.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Abnormalities, Multiple / genetics
  • Adult
  • Child, Preschool
  • Chromosome Aberrations / genetics*
  • Chromosome Aberrations / pathology
  • Chromosome Banding
  • Chromosome Disorders
  • Chromosome Inversion
  • Chromosomes, Human, Pair 18 / genetics*
  • Female
  • Humans
  • In Situ Hybridization, Fluorescence
  • Infant, Newborn
  • Intellectual Disability / genetics
  • Karyotyping
  • Male
  • Syndrome
  • Trisomy*