X-linked Aarskog syndrome: report on a novel FGD1 gene mutation. Executive dysfunction as part of the behavioural phenotype.

Aarskog-Scott syndrome [OMIM 100050] is a predominantly X-linked disorder that is phenotypically characterized by short stature, craniofacial dysmorphisms, brachydactyly and urogenital abnormalities. The level of intelligence shows a great variability and no specific behavioural phenotype has been described so far. In about 20 percent ofAarskog families, a mutation in the FGD1 gene located in Xp11.21 can be identified. In the present study, four affected males from the fourth generation of a large Dutch family (published in 1983 by Van de Vooren et al. (41)) are described. A novel FGD1 missense mutation (R402W) at position 1204 (1204C>T) was demonstrated. In the patients, the level of intelligence varied between normal and severely disabled. Their behavioural profile showed, among others, elements of attention deficit hyperactivity disorder, primarily reflected by impaired executive attentional processes that may be sensitive to systematic training.