Craniosynostosis (the premature fusion of the skull bones) is a common disorder affecting 1 in 2,250 children and so is often encountered by paediatricians and geneticists. Because of the many different genetic causes of this disease, standard diagnostic testing procedures can often miss the underlying genetic lesion. In our study we identified the genetic cause using deep sequencing of the genome in 15 patients from a cohort of 40 (37.5%), and provide specific details of 5 cases where this result has had a direct and immediate impact on the clinical decisions for the child and their families. This study highlights the impact of using these methods to identify the underlying genetic cause in cases that would otherwise have eluded routine clinical testing, in addition to identifying new disease genes to improve diagnostic and management strategies in the future. (By Dr. Kerry Miller, http://jmg.bmj.com/content/early/2016/11/24/jmedgenet-2016-104215 )