1. ¹Istituto di Neurogenetica e Neurofarmacologia INN-CNR, Cagliari, Italy
2. ²Dipartimento di Scienze Biomediche e Biotecnologie, Università degli Studi di Cagliari, Cagliari, Italy
3. ³Ospedale Regionale per le Microcitemie, Clinica Pediatrica II, Azienda U.S.L. 8 Cagliari, Cagliari, Italy

Correspondence: Dr L Crisponi, Istituto di Neurogenetica e Neurofarmacologia (INN), Consiglio Nazionale delle Ricerche, c/o Cittadella Universitaria di Monserrato, 09042 Monserrato, Cagliari, Italy. Tel: +39 070 6754591; Fax: +39 070 6754652; E-mail: laura.crisponi@inn.cnr.it

⁴These authors contributed equally to this work.

Received 3 August 2007; Revised 20 December 2007; Accepted 6 January 2008; Published online 13 February 2008.

Abstract

Recent studies estimated a rate of 3–5% of cytogenetic abnormalities involving many different chromosomes in autistic spectrum disorders (ASDs). Here, we report on two unrelated male patients with de novo translocations, autistic behaviour and psychomotor delay. These two patients carry a balanced chromosome translocation t(5;8)(q14.3;q23.3) and t(6;8)(q13;q23.2), respectively. A detailed physical map covering the regions involved in the translocations was constructed using BAC clones mapping on chromosomes 5q14.3, 6q13 and 8q23. Fluorescence in situ hybridisation (FISH) analyses were carried out using these genomic clones. We fine mapped the two translocation breakpoints on chromosomes 8 identifying their position within a short 5 Mb genomic region. Breakpoints on chromosomes 8 in both patients do not interrupt any known gene but both map in a region containing the CSMD3 gene, which thereby can be considered as a candidate for ASDs.