The incidence of Rett syndrome in males is unknown, partly owing to the low survival of male fetuses with the Rett syndrome-associated MECP2 mutations, and partly to differences between signs caused by MECP2 mutations and those caused by Retts.Females can live up to 40 years or more. Laboratory studies on Rett syndrome may show abnormalities such as:

EEG abnormalities from 2 years of age
atypical brain glycolipids
elevated CSF levels of beta-endorphin and glutamate
reduction of substance P
decreased levels of CSF nerve growth factorsA high proportion of deaths are abrupt, but most have no identifiable cause; in some instances death is the result most likely of:

spontaneous brainstem dysfunction
cardiac arrest, likely due to long QT syndrome, ventricular tachycardia or other arrhythmias
seizures
gastric perforation

History
Andreas Rett, a pediatrician in Vienna, first described the condition in 1966. As his writings were in German, they did not become widely known in the English-speaking world. Bengt Hagberg, a Swedish pediatrician, published an English article in 1983 and named the condition after Rett. In 1999, Lebanese-American physician Huda Zoghbi discovered the mutation that causes the condition. Research
Gene therapy is under study in animal models to achieve regulated expression of a normal MECP2 gene. In March 2022, Taysha Gene Therapies announced that they had received Clinical Trial Application (CTA) approval from Health Canada for a clinical trial of their investigational gene therapy for adult females with Rett Syndrome. In fiction
In August 2021, a novel by British author Victoria Scott, Patience, was published by Head of Zeus.
Consciousness will quickly be lost and the skeletal muscles will suddenly tense, often causing the extremities to be pulled towards the body or rigidly pushed away from it, which will cause the patient to fall if standing or sitting. There may also be upward deviation of the eyes with the mouth open. The tonic phase is usually the shortest part of the seizure, normally lasting only 10–20 seconds. The patient typically expresses brief vocalizations like a loud moan upon entering the tonic stage, due to air being forcefully expelled from the lungs. This vocalization is commonly referred to as an "ictal cry." Starting in the tonic phase, there may also be bluing of the skin from respiration impairment as well as pooling of saliva in the back of the throat. Increased blood pressure, pupillary size and heart rate (sympathetic response) may also be noted with clenching of the jaw possibly resulting in biting the tongue. The initial tonic phase may be preceded by repetitive rhythmic or arrhythmic jerks or by the absence seizure. Clonic phaseThe clonic phase is an evolution of the tonic phase and is caused by muscle relaxations superimposed on the tonic phase muscle contractions. This phase is longer than the tonic phase with the total ictal period usually lasting no longer than 1 min. Skeletal muscles will start to contract and relax rapidly, causing convulsions. These may range from exaggerated twitches of the limbs to violent shaking or vibrating of the stiffened extremities. The patient may roll and stretch as the seizure spreads.