MECP2 Duplication Syndrome (M2DS) is a rare genetic disorder caused by duplication of the MECP2 or Methyl CpG binding protein 2 gene located on the X chromosome (Xq28). The syndrome primarily affects males.


Common symptoms of M2DS are

  • Infantile hypotonia
  • Delayed psychomotor development
  • Severe intellectual disability
  • Minimal or absent speech
  • Gait abnormalities due to muscle spasticity-half of M2DS patients never learn to walk
  • Recurrent respiratory infections
  • Gastrointestinal issues
  • Epilepsy
  • Dysmorphic features such as brachycephaly (abnormally flat back of the head), midface hypoplasia (underdevelopment of the middle of the face), large ears, deep-set eyes, prominent chin, and a depressed nasal bridge

Link to autism

Many sufferers of M2DS display signs of Autism.[1]

Female sufferers of M2DS are rare due to skewed X-chromosome inactivation, but female carriers of the MECP2 duplication tend to show signs of Autism and other psychiatric symptoms.[2]


Currently there is no cure for M2DS. Treatment is generally supportive and based on increasing quality of life.


50% of M2DS patients die before the age of 25 due to chronic infections.

Because of the physical and mental disabilities caused by the condition, M2DS patients require lifelong care and support.


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