An Autism-Like Developmental Disorder: Rett Syndrome
Posted Nov 19 2009 10:02pm
Most people haven’t heard of Rett Syndrome, a neurodevelopmental disorder that affects primarily girls. The disease is unfamiliar because it was only in 1983 that Rett syndrome first began appearing in medical literature. Before this time (and still sometimes now), those with Rett syndrome were likely misdiagnosed with autism or cerebral palsy.
One of the hardest parts of Rett syndrome is that girls have normal development for the first 6 to 18 months and then their development plateaus. Gradually, they begin to lose motor function, lose the ability to speak, develop uncontrollable hyperventilation and seizures, develop scoliosis, and regress developmentally in other ways as well. Many of these difficulties stem from apraxia, which is the condition where the girl’s body cannot do what her brain tells it to do.
Rett syndrome occurs approximately once in 8,000 female births, but these numbers may be on the low end. The International Rett Syndrome Assocation (IRSA) notes that there may be hundreds of thousands of girls and women with Rett syndrome throughout the world who are misdiagnosed or unidentified.
Though Rett syndrome is genetically based, and testing is available, it is only passed from one generation to the next in a very small number of cases (0.5%). Much still needs to be understood about the disease; however, it is known that Rett syndrome is caused by a mutation in a gene on the X chromosome (the MECP2 gene), which encodes a protein essential for the normal function of nerve cells.
Even though most parents who have a child with Rett syndrome do not have the gene mutation and do not have the condition, in some cases a parent may carry the mutation only in some of their reproductive cells (like the eggs, or ova). According to the Rett Syndrome Research Foundation, “Prenatal testing is available for parents who have a child with an identified MECP2 mutation. Prenatal testing is possible by analysis of DNA obtained by amniocentesis usually obtained at about 15-18 weeks’ gestation or chorionic villus sampling (CVS) at about 10-12 weeks’ gestation.” More information: