Atypical Rett syndrome

Atypical Rett syndrome refers to a group of neurodevelopmental disorders that share features with classic Rett syndrome but do not meet all of its diagnostic criteria. Also known as Rett syndrome variants, these forms include several recognized subtypes: the preserved speech variant (Zappella variant), the early seizure onset variant (Hanefeld variant), and the congenital variant (Rolando variant). While classic Rett syndrome is caused by mutations in the MECP2 gene, atypical forms may be associated with mutations in MECP2, CDKL5 (particularly the early seizure variant), or FOXG1 (particularly the congenital variant). The condition predominantly affects females, though rare male cases have been reported. Atypical Rett syndrome primarily affects the central nervous system, leading to a wide spectrum of neurological and developmental impairments. Key clinical features vary by subtype but may include intellectual disability, stereotypic hand movements (such as hand wringing or washing), loss of purposeful hand skills, impaired or absent speech (though some variants retain speech ability), gait abnormalities, breathing irregularities (hyperventilation, breath-holding, air swallowing), seizures, autonomic dysfunction, scoliosis, and growth retardation. The congenital variant tends to present earlier and more severely, with developmental delays apparent from birth, while the preserved speech variant may have a milder course with some language recovery. There is currently no cure for atypical Rett syndrome, and management is primarily supportive and symptomatic. Treatment strategies include antiepileptic medications for seizure control, physical therapy and occupational therapy to maintain mobility and hand function, speech therapy, nutritional support, and orthopedic management for scoliosis. Multidisciplinary care involving neurologists, rehabilitation specialists, and other healthcare providers is essential. Research into targeted therapies, including gene therapy approaches, is ongoing but remains largely in experimental stages.

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