Balanced translocation 46,XY,t(2;15)(q37.2;q11.2) associated with atypical Prader-Willi syndrome

Am J Hum Genet. 1997 Aug;61(2):388-94. doi: 10.1086/514852.


The lack of normally active paternal genes in 15q11-q13, as an outcome of either a paternal deletion or maternal disomy, accounts for >95% of all patients with Prader-Willi syndrome. Other mechanisms, including imprinting mutations and unbalanced translocations involving pat 15q11-q13, have been described elsewhere. In this study, we present a patient with a rare balanced, de novo translocation-46,XY,t(2;15)(q37.2;q11.2)-involving breakage within the Prader-Willi/Angelman syndrome region of the paternal homologue, without an apparent deletion. The patient demonstrated several manifestations of the Prader-Willi syndrome but was clinically atypical. Cytogenetic and molecular studies of this case demonstrated the translocation breakpoint to be between SNRPN and IPW, with mRNA expression of SNRPN and PAR-5 but absence of IPW and PAR-1 expression. These results suggest that disruption of either IPW expression or a nearby gene by an upstream break may contribute to the Prader-Willi syndrome phenotype and that expression of SNRPN or other upstream genes is responsible for other aspects of the classical Prader-Willi syndrome phenotype.

Publication types

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

MeSH terms

  • Animals
  • Autoantigens / genetics
  • Child, Preschool
  • Chromosome Banding
  • Chromosome Breakage
  • Chromosomes, Human, Pair 15 / genetics*
  • Chromosomes, Human, Pair 2 / genetics*
  • Cricetinae
  • DNA Methylation
  • Fathers
  • Gene Expression
  • Genomic Imprinting
  • Humans
  • Hybrid Cells
  • In Situ Hybridization, Fluorescence
  • Kruppel-Like Transcription Factors
  • Male
  • Phenotype
  • Prader-Willi Syndrome / genetics*
  • Prader-Willi Syndrome / pathology
  • Protein Kinases*
  • Restriction Mapping
  • Ribonucleoproteins, Small Nuclear*
  • Transcription Factors / genetics
  • Translocation, Genetic*
  • snRNP Core Proteins


  • Autoantigens
  • Kruppel-Like Transcription Factors
  • PEG3 protein, human
  • Ribonucleoproteins, Small Nuclear
  • SNRPN protein, human
  • Transcription Factors
  • snRNP Core Proteins
  • Protein Kinases