Williams syndrome is a genomic disorder caused by deletion of a specific segment of chromosome 7. Due to the presence of a number of repeated sequences, this region is prone to errors during replication that can result in deletion of the intervening stretch of the chromosome, which contains approximately 28 genes. The disorder is characterised by typical facial morphology, heart defects and a remarkably consistent profile of cognitive and personality traits. These include mild intellectual disability, with relative strength in language and extreme deficits in visuospatial abilities (including being able to perceive the relationships of objects in 3D space and to construct and mentally manipulate 3D representations). Williams patients are also highly social – often to the point of being over-friendly – empathetic and very talkative. This behaviour may belie a high level of anxiety, however.
One of the most remarkable features of Williams syndrome is the strong attraction of patients for music. Many show a strong interest in music from an early age and greater emotional responses to music. They are also more likely to play a musical instrument, some using music to reduce anxiety. A recent study from Elisabeth Dykens and colleagues adds a new twist to this story. They found in a neuroimaging experiment that in addition to activating the auditory cortex, music also stimulates visual activity and perceptions in Williams patients. In fact, this is not specific to music – non-musical sounds had the same or even stronger effects.