In this form of Rett syndrome, the patients have epilepsy before 5 months of age.The definition itself of the Rett syndrome has been refined over the years: as the atypical forms subsist near to the classical form (Hagberg & Gillgerg, 1993), the "Rett Complex" terminology has been introduced. Cause
Genetically, Rett syndrome (RTT) is caused by mutations in the gene MECP2 located on the X chromosome (which is involved in transcriptional silencing and epigenetic regulation of methylated DNA), and can arise sporadically or from germline mutations. In less than 10% of RTT cases, mutations in the genes CDKL5 or FOXG1 have also been found to resemble it. Rett syndrome is initially diagnosed by clinical observation, but the diagnosis is definitive when there is a genetic defect in the MECP2 gene. It has been argued that Rett syndrome is in fact a neurodevelopmental condition as opposed to a neurodegenerative condition. One piece of evidence for this is that mice with induced Rett Syndrome show no neuronal death, and some studies have suggested that their phenotypes can be partially rescued by adding functional MECP2 gene back when they are adults. This information has also helped lead to further studies aiming to treat the disorder. Sporadic mutations
In at least 95% of Rett syndrome cases, the cause is a de novo mutation in the child. That is, it is not inherited from either parent.
DSM-5 has taken out the "culture–bound syndrome" language and replaced it with more "sensitive" language, and the glossary where the now shortened list of previously recognized culture–bound syndromes is titled "Other Specified" and "Unspecified" dissociative disorders. A more general discussion, involving the formation of a cultural identity, explanation, and assessment, has been added. In popular culture
William S. Burroughs mentions latah several times in his 1959 novel Naked Lunch, "a parody of modern mass man under modern conditioning programmes of advertising and public[ly] induced morality", according to Eric Mottram. Burroughs described latah as involving echopraxia, as well as being forcibly induced rather than spontaneously occurring. Latah is also mentioned in Burroughs 1963 novel The Yage Letters. Possible causes
The onset of latah is often associated with stress. In a study done by Tanner and Chamberland in 2001, a significant number of research participants had experienced a life stressor (such as a child or husband dying) just before becoming latah. Additionally, a large number of participants from many research studies have reported strange dreams occurring just before the onset of latah. These dreams usually had a sexual element to them, often involving penises. According to Tanner and Chamberland, perhaps the dreams, although with variation, indicate some sort of dysfunction in a specific anatomical area. Exploring this further might lead to more insights as to the cause and/or cure of latah. : 526–529  Osborne (2001) states that latah is a possible emotional outlet in a stifling culture.