[Malignancy risk and Wiedemann-Beckwith syndrome: what follow-up to provide?]

Wiedemann-Beckwith syndrome (WBS) is a syndrome of excessive growing with a high predisposition to developing embryologic tumours within the first years of life. This risk is evaluated between 7.5 and 10%; it varies with the mechanisms of mutations involved. These take place in two distinct domains of 11p15, which are under parental printing. Emerging techniques of cytogenetic and molecular biology now have shown correlations between genotypes and phenotypes, and can identify the 30% of WBS who are especially at risk of developing tumours. A specific follow-up, integrating the specificity of developing tumours of each 11p15 mutations involved, is now proposed to patients with WBS.