DDX3X Syndrome is caused by a spontaneous mutation at conception, meaning nothing that either parent did caused their child’s condition. The syndrome was discovered in 2014 and primarily affects females due to its location on the X-chromosome, though there are males with DDX3X Syndrome as well. Although it has only been identified in about 600 individuals, doctors believe it is the cause of 1 to 3 percent of all intellectual disabilities in females. 

DDX3X Syndrome is often misdiagnosed as autism spectrum disorder, cerebral palsy, Rett Syndrome, Dandy-Walker Syndrome, or a generic developmentally delayed label. 

It is linked to intellectual disabilities, seizures, autism, low muscle tone, abnormalities of the brain, and slower physical developments. It has a broad spectrum—some individuals develop the ability to speak in full sentences, while others are nonverbal. Some individuals run, jump, and even ski, while others are unable to walk.


How does the DDX3X mutation present itself?

Not all individuals with DDX3X are affected in the same ways, however, the following are common symptoms:

  • Intellectual disability
  • Developmental delays
  • Low muscle tone/hypotonia
  • Difficulty with speech
  • Epilepsy/seizures
  • Movement disorders
  • Abnormalities of the brain
  • Microcephaly


How can you join the DDX3X tribe? Please contact us if you’d like to partner with us to research DDX3X Syndrome.

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Current Research

Since 2015, we have facilitated the acceleration of research on DDX3X Syndrome by increasing the network of researchers from one to twenty and research papers from one to more than 100. Research on DDX3X gene functionality and mutations has accelerated drastically over the last years. Click below to read the research papers currently available on DDX3X Syndrome. 

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