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J Med Genet 40:352-356 doi:10.1136/jmg.40.5.352
  • Letters to JMG

The neurobeachin gene is disrupted by a translocation in a patient with idiopathic autism

  1. D Castermans1,
  2. V Wilquet1,
  3. E Parthoens1,
  4. C Huysmans1,
  5. J Steyaert2,3,5,
  6. L Swinnen4,
  7. J-P Fryns2,
  8. W Van de Ven1,
  9. K Devriendt2
  1. 1Department of Human Genetics, Division of Molecular Oncology, University of Leuven, Belgium
  2. 2Centre for Human Genetics, Division of Clinical Genetics, University of Leuven, Belgium
  3. 3Department of Children’s Psychiatry, University of Leuven, Belgium
  4. 4Child and Adolescent Psychiatrist, Neerpelt, Belgium
  5. 5Centre for Clinical Genetics, University of Maastricht, The Netherlands.
  1. Correspondence to:
 Dr K Devriendt, Centre for Human Genetics, Herestraat 49, B-3000 Leuven, Belgium; 
 koenraad.devriendt{at}uz.kuleuven.ac.be

    Autism is a developmental disorder characterised by a triad of clearly abnormal or impaired development in social interaction and communication, and a markedly restricted repertoire of activity and interests.1 Its incidence is estimated at about 1/1000 to 1/2000.2 Different metabolic and structural brain anomalies have been observed in subjects with autism but these data have not yet led to a single unifying theory on its pathogenesis. In a minority (5–10%) of cases, autism is a symptom of a recognisable disorder such as fragile X syndrome, tuberous sclerosis, or untreated phenylketonuria.3 However, the molecular pathways involved in these disorders have also not contributed to an increased understanding of the pathogenesis of autism. In the majority of cases, the cause of autism is not known but there is strong evidence for a genetic cause. A polygenic inheritance is likely but estimates on the number of interacting genes vary from two to 10.4,5 Moreover, it is likely that different combinations of genes are implicated in unrelated subjects.6 The identification of genes involved in autism is expected to increase our understanding of the pathogenesis of this disorder. Several large scale linkage studies and follow up analyses have yielded suggestive linkage to several different chromosomal regions. However, neither this approach nor the large number of association studies using candidate genes has resulted in the identification of autism susceptibility genes.5 As an alternative approach to identifying candidate genes for autism, we initiated a positional cloning strategy starting with subjects with autism carrying a de novo chromosomal anomaly. In a group of 525 subjects with autism who were karyotyped and had no recognised underlying medical condition, four were found to carry such a de novo chromosomal aberration. In none of them was there a family history of autism. Three had …