MECP2 Duplication Syndrome
MECP2 Duplication Syndrome was discovered in 2005. It is a progressive neurological disorder, primarily affecting males. Common features include non-verbal communication, infantile hypotonia (low muscle tone), global developmental delay, intellectual impairment and/or autistic traits, recurrent deadly respiratory infections, and epilepsy. Other signs and symptoms include ataxia (wobbly movements), gastro-oesophageal reflux, severe constipation, aspiration, and feeding difficulties.
Recent technological breakthroughs in communication have shown that children affected by MECP2 Duplication Syndrome have been essentially trapped within their bodies. In the very recent past, a combination of non-existent or limited speech with poor motor skills had caused these adolescent individuals to present with the cognitive abilities of an infant. Parents of these children knew that traditional assessments were not capturing the brainpower of their children. Pioneering communication work with MECP2 Duplication Syndrome children and eye gaze communication devices have begun to validate the parents as it was demonstrated that these children have the ability to communicate requests and feelings.
The genetic abnormality that causes MECP2 duplication syndrome is a double dose or duplication of the MECP2 or Methyl CpG binding protein 2 gene. The protein made by the MECP2 gene, called MECP2, plays a pivotal role in regulating brain function. Too little or too much of the MECP2 protein results in brain dysfunction and physical impairment. Mutations in the MECP2 gene are also commonly associated with Rett syndrome in females.
Advances in genetic testing and more widespread use of Array CGH (Comparative Genomic Hybridization) has lead to increased diagnosis of MECP2 duplication syndrome. Array CGH allows for sub-microscopic (cannot be seen under a microscope) detection of missing or additional copies of genetic material and is the best screening test for a child with developmental delay as it will detect a number of genetic disorders including MECP2 duplication syndrome.
Research into MECP2 duplication syndrome is in its infancy, which means we also do not know the spectrum (mildness to severity). Preliminary studies suggest that prevalence may be 1.8 per 10,000 live male births. 50% of cases do not live beyond 25 years of age.