Syndromal obesity due to paternal duplication 6(q24.3-q27)

Am J Med Genet. 1999 May 21;84(2):125-31. doi: 10.1002/(sici)1096-8628(19990521)84:2<125::aid-ajmg8>;2-w.


The likelihood of a paternally expressing imprinted gene in chromosome region 6(q23-24) has been highlighted by cases of transient neonatal diabetes mellitus (TNDM) in which paternal uniparental disomy (UPD) for chromosome 6 or paternal duplication 6(q23-qter) was detected. We present the case of a 38-year-old man with moderate to severe intellectual delay, short stature, small hands and feet, eye abnormality, small mouth, and obesity (without hyperphagia) beginning in mid-childhood. The perinatal and neonatal histories were normal. The patient had a duplication within 6q. Fluorescence in situ hybrisation studies were performed with single and dual hybridisations using a chromosome 6 library probe, short and long arm subregional probes, 6q23-24, 6q25.3-6qter locus-specific probes, and a 6q telomere probe. The hybridisation results defined an inverted duplication of 6q24.3 to 6q27. DNA studies with microsatellite markers from 6p and 6q showed regular biparental inheritance of chromosome 6 and confirmed that the duplication was paternal in origin. Our patient appears to be the first one known to have paternal duplication of chromosome area 6(q24-q27) who did not have TNDM as an infant. He has remained nondiabetic, although obesity, without hyperphagia, has been a constant problem since its onset in mid-childhood.

Publication types

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

MeSH terms

  • Adult
  • Chromosome Banding
  • Chromosomes, Human, Pair 6*
  • Diagnosis, Differential
  • Gene Duplication*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Male
  • Microsatellite Repeats
  • Obesity / etiology*
  • Obesity / genetics*
  • Prader-Willi Syndrome / diagnosis