CELL LINES AND DNA BANK OF RETT SYNDROME AND OTHER X-LINKED MENTAL RETARDATION

Mental retardation (MR) is the most frequent cause of serious handicap in humans and an important health-care problem throughout the world. It is estimated to occur in about 1-3% of the general population. It is calculated that X-linked mental retardation (XLMR) may account for about 20–25% of mentally retarded males. The number of identified genes involved in XLMR has been rapidly growing in the past years. However, many XLMR conditions are still waiting for a genetic cause. Rett syndrome (RTT) is the second cause of MR in females. MECP2 gene mutations are responsible for about 90% of RTT classic cases and for a lower percentage of RTT variant cases. Negative cases may be due to mutations in other genes. In fact, CDKL5 mutations have been recently found in patients with RTT features. However, a lot of work still has to be performed to identify the molecular alteration in MECP2 and CDKL5 negative patients. Given the high genetic heterogeneity, the number of patients available for studies is a discriminating factor. The enlargement of the DNA and cell lines bank and the improvement of the dedicated web-site described in this project will represent an essential tool for researchers working on XLMR. The sharing of these precious resources will help to identify new XLMR causative genes and to define the pathogenic mechanisms underlying these conditions.