A new member of the IL-1 receptor family highly expressed in hippocampus and involved in X-linked mental retardation

We demonstrate here the importance of interleukin signalling pathways in co gnitive function and the normal physiology of the CNS. Thorough investigati on of an MRX critical region in Xp22.1-21.3 enabled us to identify a new ge ne expressed in brain that is responsible for a non-specific form of X-link ed mental retardation. This gene encodes a 696 amino acid protein that has homology to IL-l receptor accessory proteins. Non-overlapping deletions and a nonsense mutation in this gene were identified in patients with cognitiv e impairment only. Its high level of expression in post-natal brain structu res involved in the hippocampal memory system suggests a specialized role f or this new gene in the physiological processes underlying memory and learn ing abilities.