Rett syndrome is a neurodevelopmental disorder of the grey matter of the brain that affects females more commonly than males.Genetically Rett syndrome is caused by mutations in the gene MECP2 located on the X chromosome and can arise sporadically or from germline mutations.Rett syndrome is usually caused (95% or more) by a de novo mutation in the child, i.e., not inherited from either parent.Brain levels of norepinephrine are lower in people with Rett syndromeDevelopment is typically normal until 6–18 months, when language and motor milestones regress, purposeful hand use is lost, and acquired deceleration in the rate of head growth (resulting in microcephaly in some) is seen. Hand stereotypes are typical, and breathing irregularities such as hyperventilation, breathholding, or sighing are seen in many. Early on, autistic-like behavior may be seen. The infant with Rett syndrome often avoids detection until 6–18 months, owing to a relatively normal appearance and some developmental progress. However, closer scrutiny reveals disturbance of the normal spontaneous limb and body movements that are thought to be regulated in the brainstem. The brief period of developmental progress is followed by stagnation and regression of previously acquired skills.
Currently there is no cure for Rett syndrome, but studies have shown that restoring MECP2 function may lead to a cure.