Pentanucleotide repeat-primed PCR for genetic diagnosis of spinocerebellar ataxia type 31

J Hum Genet. 2012 Dec;57(12):807-8. doi: 10.1038/jhg.2012.112. Epub 2012 Sep 20.


Spinocerebellar ataxia type 31 (SCA31) is defined by the presence of an insertion mutation containing a TGGAA repeat within the intron of the brain-expressed, associated with NEDD4 (BEAN) gene. Detecting this mutation is conventionally done by southern blotting or DNA sequencing, but these methods are technically demanding and not easily implemented in clinical diagnosis. Here, we adapted repeat-primed PCR (RP-PCR) to develop a clinical genetic test for SCA31 using only the PCR process to detect the TGGAA repeat within the insertion mutation. Pentanucleotide RP-PCR and subsequent DNA fragment analysis demonstrated characteristic ladder peaks with a 5-bp periodicity, originating from the TGGAA repeat, in 100% of samples (n=14) from SCA31 patients in whom the presence of the TGGAA repeat had been verified by DNA sequencing. No peaks were observed in a normal control and two non-SCA31 patients, in whom the TGGAA repeat was absent. This method is valuable for genetic diagnosis of SCA31 in clinical practice.

Publication types

  • Comparative Study

MeSH terms

  • Case-Control Studies
  • DNA / analysis
  • DNA / genetics
  • Endosomal Sorting Complexes Required for Transport / genetics*
  • Genetic Testing
  • Humans
  • Microsatellite Repeats / genetics*
  • Mutagenesis, Insertional / genetics*
  • Nedd4 Ubiquitin Protein Ligases
  • Polymerase Chain Reaction
  • Sequence Analysis, DNA
  • Spinocerebellar Ataxias / genetics*
  • Ubiquitin-Protein Ligases / genetics*


  • Endosomal Sorting Complexes Required for Transport
  • DNA
  • Nedd4 Ubiquitin Protein Ligases
  • Nedd4 protein, human
  • Ubiquitin-Protein Ligases