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.
The methyl-CpG binding protein 2 (MeCP2) gene has recently been identified as the gene responsible for Rett syndrome (RS), a pervasive developmental disorder considered by many to be one of the autism spectrum disorders.
Silencing of fragile X mental retardation 1 (FMR1) gene and loss of fragile X mental retardation protein (FMRP) cause fragile X syndrome (FXS), a genetic disorder characterized by intellectual disability and autistic behaviors.
In addition, emerging data suggest that PTEN mutation can synergize with mutations in other autism susceptibility genes to contribute to the development of autistic behaviors.
We review the scanty literature data on the association of Cowden syndrome and autism and emphasize that the association of progressive macrocephaly and pervasive developmental disorder seems to be an indication for screening for PTEN mutations.
Haploinsufficiency of the SHANK3 gene causes a developmental disorder, 22q13.3 deletion syndrome (known as Phelan-McDermid syndrome), that is characterized by severe expressive language and speech delay, hypotonia, global developmental delay, and autistic behavior.
Here, we present the first report of a female patient with RTT-like phenotype caused by SHANK3 (SH3 and multiple ankylin repeat domain 3) mutation, indicating that the clinical spectrum of SHANK3 mutations may extend to RTT-like phenotype in addition to (severe) developmental delay, absence of expressive speech, autistic behaviors and intellectual disability.
In humans, loss of function of Tcf4 leads to the rare neurodevelopmental disorder Pitt-Hopkins syndrome, which is characterized by intellectual disability, developmental delay and autistic behavior.
COG5-CDG (COG5 subunit deficiency) is a multisystem disease with dysmorphic features, intellectual disability of variable degree, seizures, acquired microcephaly, sensory defects and autistic behavior.
Our findings suggest that hemizygous PTCHD1 loss of function causes an X-linked neurodevelopmental disorder with a strong propensity to autistic behaviors.
A case of autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) coexisting with pervasive developmental disorder harboring SCN1A mutation in addition to CHRNB2 mutation.
We now identified homozygous and compound-heterozygous deletions and mutations via molecular karyotyping and mutational screening in CNTNAP2 and NRXN1 in four patients with severe mental retardation (MR) and variable features, such as autistic behavior, epilepsy, and breathing anomalies, phenotypically overlapping with Pitt-Hopkins syndrome.