Rett's Disorder

Rett Syndrome (RTT) is a debilitating neurological disorder diagnosed almost exclusively in females. Children with RTT
appear to develop normally until 6 to 18 months of age when they enter a period of regression, losing speech and motor
skills. Most develop repetitive hand movements, irregular breathing patterns, seizures and extreme motor control
problems. RTT leaves its victims profoundly disabled, requiring maximum assistance with every aspect of daily living.
There is no cure.
RTT was originally described by Dr. Andreas Rett of Austria in 1966, but was relatively unknown until the mid 1980's
when an article describing the syndrome was published in a well-known scientific journal.
Historically, RTT was believed to affect 1 in 10,000 females. Many scientists now believe that the prevalence of RTT is in
fact much higher. We suspect there are thousands of girls and women undiagnosed or misdiagnosed (eg. autism,
cerebral palsy). Although rare, it is possible for boys to have RTT.
RTT is caused by mutations in the gene MECP2, located on the X chromosome. RTT knows no geographic, racial or
social boundaries. Fewer then 1% of Rett cases are familial. Any expectant parent is at risk for having a child with RTT.
Over a hundred separate mutations in MECP2 have been identified to date. Drawing correlations between specific
mutations and symptoms has proven difficult.
Although some individuals with RTT die at a young age, the majority live into adulthood.


Cause
The leading cause of RTT is sporadic mutations in a gene called MECP2, located on the X chromosome. Studies have
shown that more then 95% of mutations originate from a mutated sperm.
The MECP2 gene makes a protein, also called MeCP2, believed to play a pivotal role in silencing other genes. Scientists
suspect that the inability to shut down specific genes causes the cascade of symptoms seen in RTT.
How mutations in MeCP2 lead to RTT is not well understood but is the focus of intense research. Experiments suggest
that MeCP2 is not required for early brain development but rather is essential for the maintenance of maturing brain
cells (neurons).


Symptoms and Diagnosis:
The discovery of the MECP2 gene has made possible the development of a blood test for RTT. The diagnosis of the
disorder, however, is still based on symptoms and clinical history.
At this time, approximately 85% of all patients diagnosed with RTT also test positive for an MECP2 mutation. This does
not mean that the remaining 15% do not have RTT. Although testing positive for a mutation confirms the diagnosis it is
not required. It is possible that mutations exist in an area of MECP2 that has not yet been sequenced, or perhaps other
genes contribute to RTT.
The criteria below are used for making a clinical diagnosis of RTT. Please keep in mind that RTT is a spectrum
disorder. Not all the symptoms are seen in every patient and the severity of a symptom may vary widely from patient to
patient.


Diagnostic Criteria


Supportive Criteria
Bridging The Gap ...
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