Variability of the Brachmann-de Lange syndrome.

Brachmann-de Lange syndrome (BDLS) is a relatively common multiple congenital anomaly/mental retardation syndrome, whose cause is unknown. The clinical variability of this condition is well-known. Recently some reports suggested the possible existence of a mild BDLS phenotype. We report on 30 patients in whom a diagnosis of BDLS was made or strongly suspected in 12 different Italian hospitals. Based on clinical evaluation we divided them into two groups, classical and mild BDLS cases. We compare the clinical data of these patients and we discuss the problems which arise in trying to define clear criteria of distinction between these two groups.