Contiguous deletion of SLC6A8 and BAP31 in a patient with severe dystonia and sensorineural deafness

Mol Genet Metab. 2012 May;106(1):43-7. doi: 10.1016/j.ymgme.2012.02.018. Epub 2012 Mar 5.


We report here a 6-year-old boy exhibiting severe dystonia, profound intellectual and developmental disability with liver disease, and sensorineural deafness. A deficient creatine peak in brain (1)H-MR spectroscopy and high ratio of creatine/creatinine concentration in his urine lead us to suspect a creatine transporter (solute carrier family 6, member 8; SLC6A8) deficiency, which was confirmed by the inability to take up creatine into fibroblasts. We found a large ~19 kb deletion encompassing exons 5-13 of SLC6A8 and exons 5-8 of the B-cell receptor-associated protein (BAP31) gene. This case is the first report in which the SLC6A8 and BAP31 genes are both deleted. The phenotype of BAP31 mutations has been reported only as a part of Xq28 deletion syndrome or contiguous ATP-binding cassette, sub-family D, member 1 (ABCD1)/DXS1375E (BAP31) deletion syndrome [MIM ID #300475], where liver dysfunction and sensorineural deafness have been suggested to be attributed to the loss of function of BAP31. Our case supports the idea that the loss of BAP31 is related to liver dysfunction and hearing loss.

Publication types

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

MeSH terms

  • Child
  • Creatine / urine
  • Creatinine / urine
  • Dystonia* / genetics
  • Dystonia* / metabolism
  • Gene Deletion*
  • Hearing Loss, Sensorineural* / genetics
  • Hearing Loss, Sensorineural* / metabolism
  • Humans
  • Liver / metabolism
  • Liver / pathology
  • Male
  • Membrane Proteins / genetics*
  • Nerve Tissue Proteins / genetics*
  • Plasma Membrane Neurotransmitter Transport Proteins / genetics*


  • BCAP31 protein, human
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Plasma Membrane Neurotransmitter Transport Proteins
  • SLC6A8 protein, human
  • Creatinine
  • Creatine