Sotos Syndrome

Sotos syndrome is an uncommon condition that affects approximately one in fourteen thousand of the population. Until recently, doctors would diagnose Sotos syndrome on the basis of several common features that include characteristic facial appearance, a degree of learning disability, increased head circumference and large stature. A sample of blood was often taken for genetic testing that could rule out similar syndromes and an x-ray of the wrist could be used to check for advanced bone growth which is another characteristic of Sotos syndrome. However, in 2004 a Japanese research team discovered that most children with Sotos syndrome have a fault in the NSD1 gene and a genetic test is now available that can be used to give a definitive diagnosis. Unfortunately, approximately ten percent of the children who had been diagnosed with Sotos syndrome before the genetic test was available appear to have no abnormality in the NSD1 gene. This may be because they have a fault in the gene that cannot be detected by the test or because they have a fault in another gene that is related to NDS1.