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Query: UMLS:C0004352 (autism)
 32,579 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe the case of a patient with Rett syndrome, a syndrome characterized by progressive infant encephalopathy, developmental delay, dementia, autism, ataxia, microcephaly, spastic paraparesis, and autonomic neuropathy with constipation. At colonoscopy, multiple foci of tiny white, sessile, polypoid lesions were seen throughout the colon and rectum, mimicking the appearances of small hyperplastic or adenomatous polyps, associated with generalized melanosis coli. This is the first case to our knowledge describing melanosis coli in a patient with Rett syndrome. As melanosis pigment deposition is characteristically not seen in lymphoid tissue, the lymphoid tissue was identifiable at endoscopy as multiple white nodules mimicking generalized colonic polyposis throughout the colon. We discuss the likely mechanisms of lymphoid hyperplasia and coexistent melanosis coli in Rett syndrome.
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PMID:Colonic lymphoid hyperplasia in melanosis coli. 1147 72

Increased central-parietal EEG theta-2 activity (about 6.5 per sec) was found in children with cognitive disorders (in Rett's syndrome, fragile X-syndrome, infantile autism) and in elderly patients with Alzheimer-type dementia (with prevalence of neuropsychological "frontal" disorders) in the presence of suppressed alpha rhythm. This theta-activity was closely associated with cognitive deficits and possessed a specific functional topography, namely it focused in the parietal region and suppressed by both visual stimulation and motor tests. The similar EEG pattern was observed in some patients treated with neuroleptics and/or during hyperventilation. By taking into account the data available in the literature on motor, oculomotor, regional cerebral blood flow and the probability prediction in frontal lobar dysfunction, it is suggested that the theta-activity described appears in the visuomanual coordination system and is a physiological correlate of decreased functional status of frontal lobes.
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PMID:[Quantitative EEG correlates of the human frontal lobe dysfunction]. 1152 30

The paper provides clinical and catamnestic descriptions of 240 children with infantile autism; 160 with atypical autism (of them 100 had schizophrenic attacks, 60 presented with mental retardation concurrent with atypical autism (in phenylketonuria, tuberose sclerosis, Down syndrome, Martin-Bell syndrome), 20 with Asperger's syndrome, 60 with Rett's syndrome, 20 with psychogenic paraautism according the Nissen classification. The similarity of autism-like disorders and atypical autism was considered. Syndromal verifications in accordance with ICD-10 (1994) and ICD-10 (1999) in Russian versions and clinical nosological verifications adopted in Russia were studied in all the examinees. New approaches to treating patients with autistic disorders were developed.
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PMID:[Current approaches to the problem of autism in childhood]. 1152 31

The maturational changes in the brain and spinal cord do not linearly proceed from immature in infants to mature in adults. Dendrites dynamically extend or retract as neurotrophic factors fluctuate. In certain cases mature neurons can be seen soon after birth, and in other cases immature neurons can be identified in the aged brain. Monoamine 'neurotransmitter'; such as serotonin (5-HT), dopamine and norepinephrine appear to function as Maintenance Growth Factors since they must be present in order to produce their maturational actions. Serotonin neurons contain TRK-B receptors and are sensitive to availability of the trophic factor, BDNF. 5-HT also functions by promoting the release of the glial extension factor, S-100beta. 5-HT and S-100beta can provide maturational signals to a variety of neurons, in both cortical and subcortical areas, and appear to be involved in regulating the maturation and release of acetylcholine and dopamine. We have shown that activation of the 5-HT1A receptor is particularly effective in inducing growth of stunted neurons. The mechanism of action of the 5-HT1A receptor involves both a direct inhibition on c-AMP and pCREB formation in postsynaptic neurons and a release of S-100beta from glial cells. Both these events are capable of stabilization and elaboration of the cytoskeleton of the neuron and inhibition of apoptosis. 5-HT1A receptors have been shown to effectively reverse stunted neurons and microencephaly produced in animal models of fetal alcohol syndrome and prenatal cocaine administration. I discuss the implications for regressive disorders such as Rett's syndrome and autism, and the feasibility of treatments with 5-HT1A agonists in children with developmental disorders.
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PMID:Neuronal instability: implications for Rett's syndrome. 1173 34

Recent studies have demonstrated that biogenic amines have a function of facilitating formation and maintenance of synapses in diverse regions of the central nervous system in developing and adult animals. The normal number of synapses maintained by biogenic amines are crucial to acquire learning and memory. The level of biogenic amines was reported to decrease in the brain by several neurodevelopmental disorders associated with mental retardation and developmental disabilities such as Rett syndrome, autism and Down syndrome. Taken into consideration this fact together with the function of biogenic amines for synapses, the density of synapses appears to decrease considerably in the brains of patients suffered from the neurodevelopmental disorders. The synaptic overproduction during the critical period of development especially 1 year after birth has been considered as a background mechanism to provide plasticity for the developing brain. Synaptic overproduction does not appear to occur in the brains of patients suffered from the neurodevelopmental disorders, which they are observed mental retardation occurring in the first 1 year after birth. Along with the neurodevelopmental disorders, environmental factors (stress, drugs and nutrition) during pre- and post-natal critical developmental periods are known to change levels of biogenic amines in the brain. In fact, maternal stress has been shown to decrease the levels of serotonin and the density of synapses in the hippocampus of the offspring, and they showed developmental disabilities in the spatial learning and memory. A cascade appears to exist from either the child neurological disorders or the environmental factors to mental retardation and developmental disabilities by decreases in the levels of biogenic amines and synaptic density.
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PMID:A biogenic amine-synapse mechanism for mental retardation and developmental disabilities. 1173 35

In patients with Rett syndrome (RS), a peculiar type of disturbance in phasic chin muscle activity during rapid-eye-movement sleep (REMS) (e.g. an elevation of phasic inhibition index (PII) without an affection of tonic inhibition index (TII)) has been reported. The similar disturbance in REMS was reported not only in child patients with infantile spasms, severe myoclonic epilepsy in infancy (SMEI), severe nocturnal enuresis, and autism but also in adult patients with Parkinson's disease (PD). Except for SMEI and PD, patients with the other four clinical entities including RS could express autistic tendency. Since the responsible lesion for the occurrence of an elevation of PII with a normal TII value is likely to be in the pontine tegmentum, this subcortical structure is hypothesized to be involved in the appearance of autistic tendency.
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PMID:Disturbance of phasic chin muscle activity during rapid-eye-movement sleep. 1173 53

A possible role for Hoxa1 genotype in susceptibility to autism spectrum disorders was recently proposed. Furthermore, it has been demonstrated that Rett syndrome, which is categorized into pervasive developmental disorders the same as the autism spectrum disorders are, is associated with mutations in MECP2 gene. These findings suggest that the genetic backgrounds of these behavioral conditions may involve genes which also have an important role in the development of skull, because Hoxa1 is a key gene for skull development as well as for brain development and one of the clinical characteristics of Rett syndrome is deceleration in head growth. Together with this evolving knowledge, a series of ethical arguments concerning the indication of surgical treatment in patients with minor forms of trigonocephaly with autistic behaviors and/or hyperactivity leads us to hypothesize the presence of an autism subtype which may frequently be accompanied by specific morphological skull characteristics (autistic skull shape).
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PMID:Minor form of trigonocephaly is an autistic skull shape? A suggestion based on homeobox gene variants and MECP2 mutations. 1202 29

Although MECP2 was initially identified as the causative gene in classic Rett syndrome (RTT), the gene has now been implicated in several phenotypes that extend well beyond the clinically defined disorder. MECP2 mutations have been found in people with various disorders, including neonatal onset encephalopathy, X-linked recessive mental retardation (MRX), classic and atypical RTT, autism, and Angelman syndrome, as well as mildly affected females and normal carrier females. To make matters more complex, in approximately 20% of classic sporadic RTT cases and more than 50% of affected sister pairs, no mutation in MECP2 has been found. X-chromosome inactivation patterns can clearly affect the phenotypic expression in females, while the effect of the type and position of the mutation is more apparent in the broader phenotype than in RTT. Both males and females are at risk, although an excess of paternally derived mutations are found in most cases of classic RTT. Thus, because of the range of disparate phenotypes, the gene may account for a relatively large portion of mental retardation in the population.
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PMID:The phenotypic consequences of MECP2 mutations extend beyond Rett syndrome. 1211 34

Rett syndrome (RTT) is classically defined by meeting certain clinical diagnostic criteria. It affects mostly females, and one possible pathogenic mechanism was considered to involve mitochondrial function. This was based on the finding of ultrastructural alterations in the mitochondria and decreased respiratory chain enzyme activity. However, the principal etiology of RTT has since been found to be mutations in the MECP2 gene, which is located on the X chromosome. Molecular analysis has allowed the phenotype of MECP2 mutations to be broadened beyond RTT to include girls who have mild mental retardation, autism, and an Angelman syndrome phenotype, as well as males with severe encephalopathy. We present a girl with a previously described mutation in the MECP2 gene whose phenotype is of atypical RTT. She presented with hypotonia and developmental delay in infancy without a clear period of normal development. As part of her evaluation for hypotonia, a muscle biopsy and respiratory chain enzyme analysis showed a slight decrease in respiratory chain enzyme activity consistent with previous reports. This report supports broadening the phenotype of patients who should be considered for MECP2 mutation analysis to include cases of developmental delay and hypotonia without evidence of an initial period of normal development. Furthermore, it supports the hypothesis of an underlying secondary defect in energy metabolism contributing to the pathogenesis of RTT.
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PMID:Infantile hypotonia as a presentation of Rett syndrome. 1221 Mar 19

Rett syndrome is a neuro-developmental disorder related to autistic behavior. Persons with autism have previously been found to have hyperpeptiduria. We here report a significantly higher level of peptides in the first fasting morning urine from 53 girls with Rett syndrome (both classical and congenital) compared with 53 healthy girls. This elevation in urinary peptides was similar to that in 35 girls with infantile autism. As in persons with autism, the individual levels of urinary peptides in the Rett syndrome group varied, and about a fifth were within the normal range. Levels of peptides were lower in girls with classic Rett syndrome than in girls with congenital Rett syndrome. This may be due to different etiological causes or to active and stagnant phases of the disease. Urine from girls with Rett syndrome was found to have higher frequency and higher levels of some urinary peptides that may cause inhibition of brain maturation and epilepsy
Autism 2002 Sep
PMID:Urinary peptides in Rett syndrome. 1221 21


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