Treacher Collins syndrome: clinical, genetic and molecular aspects

Abstract

Treacher Collins syndrome (TCS) is an autosomal dominant defect in craniofacial development affecting approximately 1150.000 newborns. Roughly 60% of cases are due to nove1 mutations. Marked clinical variability can make diagnosis difficult sometimes, especially when the patient is mildly affected. Ever since the identification of the gene associated with the syndrome in 1996, a number of different mutations causing TCS has been described. Most of these mutations are farnily-specific, mahng the screening of rnutations labor intensive but, nonetheless, extremely useful when the clinical diagnosis is uncertain. Despite recent advances in the molecular characterization of TCS, the causes of the great clinical variability observed even within members of a same family remain unknown. Identifying factors that contribute to the severity of the syndrome will probably be a major challenge for researchers on TCS, and will certainly improve genetic counseling to the families.