Polymorphisms in the 13q33.2 gene G72/G30 are associated with childhood-onset schizophrenia and psychosis not otherwise specified

Biol Psychiatry. 2004 May 15;55(10):976-80. doi: 10.1016/j.biopsych.2004.01.024.


Background: Childhood-onset schizophrenia (COS), defined as onset of psychotic symptoms by age 12 years, is a rare and severe form of the disorder that seems to be clinically and neurobiologically continuous with the adult disorder.

Methods: We studied a rare cohort consisting of 98 probands; 71 of these probands received a DSM-defined diagnosis of schizophrenia, and the remaining 27 were diagnosed as psychosis not otherwise specified (NOS) (upon 2-6 year follow-up, 13 have subsequently developed bipolar disorder). Two overlapping genes, G72 and G30 on 13q33.2, were identified through linkage-disequilibrium-based positional cloning. Single nucleotide polymorphisms (SNPs) at the G72/G30 locus were independently associated with both bipolar illness and schizophrenia. We analyzed SNPs at this locus with a family-based transmission disequilibrium test (TDT) and haplotype analyses for the discrete trait, as well as quantitative TDT for intermediate phenotypes, using the 88 probands (including COS and psychosis-NOS) with parental participation.

Results: We observed significant pairwise and haplotype associations between SNPs at the G72/G30 locus and psychotic illness. Furthermore, these markers showed associations with scores on a premorbid phenotype measured by the Autism Screening Questionnaire, and with age of onset.

Conclusions: These findings, although limited by potential referral bias, confirm and strengthen previous reports that G72/G30 is a susceptibility locus both for schizophrenia and bipolar disorder.

Publication types

  • Comparative Study

MeSH terms

  • Age of Onset
  • Carrier Proteins / genetics*
  • Child
  • Chromosome Mapping
  • Chromosomes, Human, Pair 13*
  • Cohort Studies
  • Family Health
  • Follow-Up Studies
  • Gene Frequency
  • Genetic Predisposition to Disease
  • Haplotypes
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Linkage Disequilibrium
  • Polymerase Chain Reaction / methods
  • Polymorphism, Single Nucleotide*
  • Psychiatric Status Rating Scales
  • Psychotic Disorders / genetics*
  • Schizophrenia, Childhood / genetics*
  • Surveys and Questionnaires


  • Carrier Proteins
  • DAOA protein, human
  • Intracellular Signaling Peptides and Proteins