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.
Moreover, a reduction of the tyrosine hydroxylase (Th) mRNA level, the rate-limiting enzyme in catecholamine synthesis, was detected in the whole pons of MECP2-null male as well as in adult heterozygous (MECP2+/-) female mice. Using immunoquantitative techniques, a decrease of Th protein staining level, number of locus coeruleus TH-expressing neurons and density of dendritic arborization surrounding the structure was shown in symptomatic MeCP2-deficient mice. However, locus coeruleus cells are not dying, but are more likely losing their fully mature phenotype, since no apoptotic neurons in the pons were detected.Researchers have concluded that "Because these neurons are a pivotal source of norepinephrine throughout the brainstem and forebrain and are involved in the regulation of diverse functions disrupted in Rett syndrome, such as respiration and cognition, we hypothesize that the locus coeruleus is a critical site at which loss of MECP2 results in CNS dysfunction." The restoration of normal locus coeruleus function may therefore be of potential therapeutic value in the treatment of Rett syndrome. Midbrain dopaminergic disturbances
The majority of dopamine in the mammalian brain is synthesized by nuclei located in the mesencephalon. The substantia nigra pars compacta (SNpc), the ventral tegmental area (VTA) and the retrorubral field (RRF) contains dopaminergic neurons expressing tyrosine hydroxylase (Th, i.e. the rate-limiting enzyme in catecholamine synthesis).The nigro-striatal pathway originates from SNpc and irradiate its principal rostral target, the Caudate-Putamen (CPu) through the median forebrain bundle (MFB).