Whole exome sequencing based identification of a case of cardiofaciocutaneous syndrome type 3: the benefits of new sequencing technology in children with neurodevelopmental delay

We report the case of a boy with a prolonged diagnostic workup for global developmental delay alongside feeding difficulties, failure to thrive, pulmonary stenosis and macrocephaly. Following a series of diagnostic tests over the first 25 months of life, whole-exome sequencing was performed which diagnosed cardiofaciocutaenous syndrome type 3.Global developmental delay is a common presentation to general paediatric and community paediatric clinics. This prompts the search for an aetiology to describe the child's constellation of symptoms which often consists of a chromosomal microarray, neuroimaging and investigations for an inborn error of metabolism. With developments in genetic testing such as the reducing cost of clinical exome sequencing or whole-exome sequencing, could these testing strategies offer a more comprehensive first line test?This case not only demonstrates the features of cardiofaciocutaneous syndrome type 3 but the added value of modern genetic technologies in the diagnosis of children with global developmental delay.