Rett syndrome is a progressive neurodevelopmental disorder, primarily affecting females. Rett syndrome is characterized by acquired microcephaly, loss of purposeful hand movements, and autistic behaviors, following a period of normal growth and development. Sequence mutations are present in 80% of girls with classic Rett syndrome and 20% of girls with a variant diagnosis. MECP2 mutations are also found in:
• Females with atypical Rett syndrome (preserved speech variant or congenital onset)
• Males with moderate to severe, non-specific mental retardation and encephalopathy
• Males with features similar to classic Rett syndrome
• Families with X-linked mental retardation: ~2% of males with X-linked mental retardation have mutations in MeCP2.
• Approximately 10% of children with Angelman syndrome-like phenotype but normal methylation and UBE3A studies have a MeCP2 mutation.
MECP2 sequencing is available as an individual test, or as part of the following panels: Rett/Atypical Rett syndrome panel, Angelman syndrome tier 2 panel, and X-Linked and Comprehensive Intellectual Disability Panels. Please see our information sheets for more details.