Mutations in MECP2 gene account for approximately 80% of cases of Rett syndrome (RTT), an X-linked severe developmental disorder affecting young girls, as well as for most cases of Preserved Speech Variant (PSV), a mild RTT variant in which autistic behavior is common.
Point mutations and genomic rearrangements in the MECP2 gene are the major cause of Rett syndrome (RTT), a pervasive developmental disorder affecting almost exclusively females.
CARS scores increased slowly, yet significantly, over time, and low levels of FMRP were associated with higher mean levels of autistic behavior as measured by the CARS.
Longitudinal analyzes of Leiter scores consisted primarily of hierarchical linear modeling, with the impact of chronological age, maternal education, fragile X mental retardation 1 protein (FMRP), autistic behaviors also being assessed.
When deficient, Fragile X Mental Retardation Protein (FMRP) causes developmental deficits and autistic behaviors while TAR-DNA Binding Protein (TDP-43) dysregulation causes age dependent neuronal degeneration.
Fragile X syndrome, caused by mutations in a single gene of the X chromosome (FMR1), is associated with neurobehavioral characteristics including social deficits with peers, social withdrawal, gaze aversion, inattention, hyperactivity, anxiety, depression, and autistic behavior.
Although abnormal regulation of neuronal genes due to mutant MeCP2 is thought to induce autistic behavior and impaired development in RTT patients, precise cellular mechanisms underlying the aberrant neural progression remain unclear.
Patients exhibit a variety of symptoms predominantly linked to the function of FMRP protein in the nervous system like autistic behavior and mild-to-severe intellectual disability.
We used a battery of standardised measures of behaviour and functioning to test the following hypotheses: (1) autistic behaviour is prominent throughout childhood in RTT; (2) autistic features are more salient in individuals with milder presentation; (3) severity of autistic behaviour is associated with a wider range of behavioural problems; and (4) specific MECP2 mutations are linked to more severe autistic behaviour.