Translocation breakpoint disrupting the host SNHG14 gene but not coding genes or snoRNAs in typical Prader-Willi syndrome

J Hum Genet. 2019 Jul;64(7):647-652. doi: 10.1038/s10038-019-0596-2. Epub 2019 Apr 15.

Abstract

Prader-Willi syndrome (PWS) is a well-known imprinting disorder arising from a loss of paternally imprinted gene(s) at 15q11.2-q13. We report a typical PWS patient with a balanced reciprocal translocation, 46, XY, t(15;19)(q11.2;q13.3). After Illumina whole-genome sequencing, we used BreakDancer-1.45 software to predict candidate breakpoints and manually investigated via the Integrated Genome Viewer. Breakpoint PCR followed by Sanger sequencing determined the t(15;19) breakpoints. We investigated the expression of upstream/centromeric and downstream/telomeric genes of the 15q11.2 breakpoint by reverse transcriptase PCR, using total RNA extracted from the patient's lymphoblasts. Of note, the expression of paternally expressed genes PWAR6, SNORD109A/B, SNORD116, IPW, and PWAR1, downstream of the breakpoint, was abolished. Interestingly, the breakpoint did not destroy protein coding genes or individual snoRNAs. These results indicate that these genes may play a major role in the PWS phenotype.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Chromosome Breakpoints
  • Chromosomes, Human, Pair 15 / genetics*
  • Chromosomes, Human, Pair 15 / metabolism
  • Chromosomes, Human, Pair 19 / genetics*
  • Chromosomes, Human, Pair 19 / metabolism
  • Genomic Imprinting / genetics
  • Humans
  • Male
  • Phenotype
  • Prader-Willi Syndrome / diagnosis
  • Prader-Willi Syndrome / genetics*
  • Prader-Willi Syndrome / metabolism
  • RNA, Long Noncoding / genetics*
  • RNA, Small Nucleolar / biosynthesis
  • RNA, Small Nucleolar / genetics
  • RNA, Small Nucleolar / metabolism
  • Translocation, Genetic*
  • Whole Genome Sequencing

Substances

  • RNA, Long Noncoding
  • RNA, Small Nucleolar
  • SNORD116 RNA, human