1. ¹Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
2. ²Department Human Molecular Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany

Correspondence: Dr A Tzschach, Department Human Molecular Genetics, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, 14195 Berlin, Germany. Tel: +49 30 8413 1416; Fax: +49 30 8413 1383; E-mail: tzschach@molgen.mpg.de

Received 7 April 2008; Revised 1 July 2008; Accepted 30 July 2008; Published online 10 September 2008.

Abstract

We report on three siblings with a novel mental retardation (MR) syndrome who were born to distantly related Iranian parents. The clinical problems comprised severe MR, cataracts with onset in late adolescence, kyphosis, contractures of large joints, bulbous nose with broad nasal bridge, and thick lips. Two patients also had uni- or bilateral iris coloboma. Linkage analysis revealed a single 10.4 Mb interval of homozygosity with significant LOD score in the pericentromeric region of chromosome 4 flanked by SNPs rs728293 (4p12) and rs1105434 (4q12). This interval contains more than 40 genes, none of which has been implicated in MR so far. The identification of the causative gene defect for this syndrome will provide new insights into the development of the brain and the eye.