Conflict of interest: none.
Homozygous deletion in TUSC3 causing syndromic intellectual disability: A new patient
Article first published online: 4 JUL 2013
Copyright © 2013 Wiley Periodicals, Inc.
American Journal of Medical Genetics Part A
Volume 161, Issue 8, pages 2084–2087, August 2013
How to Cite
2013. Homozygous deletion in TUSC3 causing syndromic intellectual disability: A new patient. Am J Med Genet Part A. 161A:2084–2087., , , , , , , , .
- Issue published online: 24 JUL 2013
- Article first published online: 4 JUL 2013
- Manuscript Accepted: 14 APR 2013
- Manuscript Received: 6 MAR 2013
- Italian Ministry of Health. Grant Number: RC2012
- autosomic recessive mental retardation (ARMR);
- intellectual disability;
- homozygous 8p22 deletion;
- TUSC3 gene
Defects in the TUSC3 gene have been identified in individuals with nonsyndromic autosomal recessive intellectual disability (ARID), due to either point mutations or intragenic deletions. We report on a boy with a homozygous microdeletion 8p22, sizing 203 kb, encompassing the first exon of the TUSC3 gene, detected by SNP-array analysis (Human Gene Chip 6.0; Affymetrix). Both nonconsanguineous parents come from a small Sicilian village and were heterozygous carriers of the microdeletion. The propositus had a few dysmorphic features and a moderate cognitive impairment. Verbal communication was impaired, with an inappropriate phonetic inventory, important phono-articolatory distortions, and bucco-phonatory dyspraxia. Comprehension was possible for simple sentences. Behavior was characterized by motor instability, high tendency to irritability and distraibility, anxiety traits, and an oppositional-defiant disorder. His parents were of normal intelligence. TUSC3 is thought to encode a subunit of the endoplasmic reticulum-bound oligosaccharyltranferase complex that catalyzes a pivotal step in the protein N-glycosylation process. TUSC3 has been recently reported as a member of the plasma membrane Mg2+ transport system, with a possible involvement in learning abilities, working memory and short- and long-term memory. This is the third family in which a deletion has been described. Although the pathogenic mechanism has not been clarified yet, our report argues for a more prominent role of TUSC3 in the etiology of intellectual disability and that deletions encompassing this gene could be more common than expected. © 2013 Wiley Periodicals, Inc.