Analysis of the pseudoautosomal X-linked gene SYBL1 in bipolar affective disorder: Description of a new candidate allele for psychiatric disorders

Takuya Saito, Sam Parsia, Demitri F. Papolos, Herbert M. Lachman

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


The absence of father-to-son transmission has been observed in a subset of families with bipolar disorder (BPD), suggestive of a susceptibility gene on the sex-linked portion of the X chromosome. This is supported by some genetic linkage studies that have provided evidence for a susceptibility locus near Xq28. We have analyzed one candidate gene on Xq28, SYBL1, which maps to the Xq pseudoautosomal region (PAR). SYBL1 encodes a member of the synaptobrevin family of proteins that is involved in synaptic vesicle docking and membrane transport. Genes in the PAR generally escape X chromosome inactivation and have an active homolog on the Y chromosome, which would result in an increase in same-sex concordance in paternal transmitted traits. However, SYBL1 is neither expressed on the Y chromosome nor the inactive X chromosome and would therefore be expected to show typical sex-linked transmission. We have screened SYBL1 for mutations that could be tested as candidate alleles in the development of BPD. Following single-strand conformation polymorphism (SSCP) analysis and DNA sequencing, four single nucleotide polymorphisms were detected: a silent mutation at codon 108, two intron mutations without any obvious biological significance, and a G→C transversion in the polypyrimidine tract at the 3' splice acceptor site preceding exon 8. This polymorphism, which creates a perfect 16/16 stretch of pyrimidines, was analyzed in 110 patients with BPD not selected for sex- linked transmission and 119 control subjects. The results show a statistical trend toward an increase in the frequency of the C allele in males with BPD but not females. Males: χ2 = 3.46, 1 df, p = .06; Females: χ2 = .20, 1 df, p = .66. (C) 2000 Wiley-Liss, Inc.

Original languageEnglish (US)
Pages (from-to)317-323
Number of pages7
JournalAmerican Journal of Medical Genetics - Neuropsychiatric Genetics
Issue number3
StatePublished - Jun 12 2000


  • Attention deficit hyperactivity disorder (ADHD)
  • Handedness
  • Laterality
  • Manic depressive illness
  • Schizophrenia

ASJC Scopus subject areas

  • Genetics(clinical)
  • Psychiatry and Mental health
  • Cellular and Molecular Neuroscience


Dive into the research topics of 'Analysis of the pseudoautosomal X-linked gene SYBL1 in bipolar affective disorder: Description of a new candidate allele for psychiatric disorders'. Together they form a unique fingerprint.

Cite this