XXXX in Tunisia: first description of clinical features and germline mutations.

@entity1 @entity6756 @entity20701 @entity4309 @entity5 @entity4311 @entity14 @entity694 @entity4638
PURPOSE: High rates of early @entity14 ( @entity14 ) are observed in Tunisia suggesting genetic susceptibility. Nevertheless, up to now, no molecular study has been performed in the Tunisian population. In our research, we evaluated the clinical characteristics of Tunisian families suspected of @entity4309 and the contribution of DNA mismatch repair (MMR) genes. METHODS: Thirty-one unrelated families suspected of @entity4309 were studied. Probands were tested for the presence of germline mutations in the MMR genes @entity6756 , @entity4311 , @entity4638 and in @entity20701 . Available @entity5 were analysed for microsatellite instability and expression of MMR proteins. Detailed family and medical histories were collected. RESULTS: A total of 134 @entity5 were noted in the 31 families, the most frequent type of @entity5 corresponding to @entity14 (69%), followed by uterine @entity5 (7.5%). Germline mutations were identified in 11 (35.5%) families (six @entity4311 , five @entity6756 , including seven novel mutations), seven of which fulfilled the Amsterdam criteria (sensitivity, 63.6%; positive predictive value, 58.3%). Noteworthy, germline mutations were detected in 52.6% of male @entity1 tested, but in only 8.3% of females (p = 0.02). Moreover, @entity14 were essentially left sided in families without detected mutation (p = 0.017). Ages of onset of @entity5 and @entity5 spectrum were very similar in families with or without MMR germline mutation, contrasting with previous studies performed in other populations. CONCLUSIONS: MMR genes contribute significantly to @entity14 susceptibility in the Tunisian population. However, the cause of early @entity14 susceptibility remains unknown in most cases, especially in @entity1 and in @entity1 with early left @entity694 .
