Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004352 (autism)
 32,579 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A previous report suggested that plasma dopamine-beta-hydroxylase (DBH) is elevated in childhood autism. We measured plasma DBH in 15 Children with functional psychosis and in 10 psychotic children with known organic etiology. DBH activity was significantly elevated in the children with functional psychoses and showed a significant correlation with age that is not reported for this age range in normals. It is possible that children with functional psychoses show an abnormal continuation of the rise in plasma DBH activity characteristic of infancy. No differences between children with functional psychoses and children with organic psychoses were found for red blood cell catechol-O-methyl-transferase, plasma monoamine oxidase, or plasma cyclic AMP.
J Autism Child Schizophr 1978 Sep
PMID:Plasma dopamine-beta-hydroxylase in childhood psychosis. 21 Nov 13

In order to evaluate the possible abnormality in monoamine oxidase (MAO) activity in early infantile autism, blood platelet samples were obtained from 20 autistic children, aged 2--12 years. MAO activity, measured fluorometrically using serotonin as substrate, was 5.24 +/- 1.65 (Mean +/- Standard Deviation) nM/MG protein/hour in these autistic children. This value was not significantly different from either that in 30 age-matched normal children or that in 39 nonautistic children with various psychiatric and neurological disorders, although autistic children had higher platelet serotonin concentration than these nonautistic individuals.
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PMID:Monoamine oxidase activity in blood platelets from autistic children. 60 61

Platelet monoamine oxidase (MAO) activity was studied in 31 individuals suffering from early childhood autism and was not significantly different from that found in normal children or adults. In the autistic children, MAO activity decreased with age, and there was a trend toward greater platelet MAO activity in prepubertal and pubertal male autistic children relative to normal male children. Total platelet counts were not elevated in autistic children.
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PMID:Platelet monoamine oxidase in early childhood autism. 87 Dec 32

Platelet monoamine oxidase activity was measured in 9 autistic subjects and 9 controls. There were no significant differences in the rates of metabolism of 5-hydroxytryptamine, dopamine or tyramine between the two groups, although the rate of metabolism of tyramine was more rapid than 5-hydroxytryptamine or dopamine within each group. It is concluded that the data presented do not support the view that measurement of platelet monoamine oxidase can be used as a biochemical index to aid in the clinical diagnosis of infantile autism.
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PMID:Platelet monoamine oxidase in children with infantile autism. 118 19

The serotonin metabolism was extensively studied in 22 couples of autistic children and age- and sex-matched controls. Histamine, calcium, and uric acid were also measured in urine and whole blood or plasma. Autistics and controls did not differ in histamine, and only minor changes were noticed in calcium content. According to previous reports, serotonin levels were often, but not always, elevated in the blood of autistic children. Based on data including urinary serotonin and 5-hydroxyindoleacetic acid, platelet serotonin uptake and efflux, platelet monoamine oxidase and glutathione peroxidase activities, and uric acid and plasma tryptophan, the origin(s) of such hyperserotonemia in autism appear(s) to be of metabolic origin, i.e., a decreased catabolism and/or an increased biosynthesis of serotonin.
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PMID:Serotonin metabolism and other biochemical parameters in infantile autism. A controlled study of 22 autistic children. 246 21

In this controlled study of 22 autistic children and 22 normal controls matched for age and sex, the frequency of hyperserotonemia in infantile autism was confirmed. Platelet serotonin was elevated in patients. Comparative to controls, serotonin was also high in urine of autistic patients, while, on the contrary there was no difference for the urinary excretion of 5-HIAA. No difference was observed either for serotonin uptake and efflux or for MAO activity, in isolated platelets. The elevation of plasma free tryptophan - significant only with the Kolmogorov Smirnov test - suggests that 5-HT biosynthesis might be enhanced. In the group of patient reported in this study, disorders of serotonin metabolism are associated with disturbances of platelet catecholamines, and also with elevated immunoglobulins and enhanced cellular immunity reactions.
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PMID:[Metabolism of serotonin in autism in children]. 306 46

The author reviews some of the neurophysiological and biochemical date more relevant on the autism. Making emphasis in the EEG, evoked potentials and some metabolical determinations: MAO, HVA, 5-HIAA, COMT.
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PMID:[Neurophysiological and biochemical criteria in the diagnosis of infantile autism]. 667 99

Autism is one of a group of pervasive developmental disorders (PDD) characterized by qualitative impairments in reciprocal social communication and by a preference for repetitive, stereotyped activities, interests, and behaviors. The disorder is caused in large part by genetic mechanisms, though no disease genes have yet been identified. The objective of this study was to investigate three markers, two in the DBH gene and one in the MAO-A gene, for maternal or fetal modifier effects on level of functioning (IQ). At the same time, the possibility of maternal or fetal susceptibility effects was also examined. We assembled 67 affected sibpairs and 45 singletons and determined allele frequencies at the three markers among the affected children and first degree relatives. Sizeable and significant modifier effects were found at the MAO locus and, to a lesser extent, at the DBH locus. Susceptibility effects were also found but not without qualification. We conclude that maternal genotypes at the MAO-A locus, and possibly at the DBH one, may modify IQ in children with autism through the intrauterine environment.
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PMID:Modifier effects in autism at the MAO-A and DBH loci. 1504 49

Serotonin (5HT) is a biologically active amine present in mammals in the brain and the peripheral tissues. Autism is a neurodevelopmental disorder in which 5HT homeostasis is disturbed both centrally and peripherally, but the relationship between the 5HT disturbances in the two compartments is not understood. In an attempt to explore the relationship between the disturbed peripheral 5HT homeostasis and central 5HT functioning, we exposed the developing rat brain to increased 5HT concentrations, by treatment of rats with subcutaneous injections of the immediate 5HT precursor 5-hydroxy-L-tryptophan (5HTP, 25 mg/kg), or the non-selective MAO inhibitor tranylcypromine (TCP, 2 mg/kg), during the period of the most intensive development of 5HT neurons--from gestational day 13 to post-natal day 21. The effects of the mentioned treatments on peripheral and central 5HT levels were then studied in adult rats. Platelet and plasma 5HT concentrations (measured by ELISA), as well as cortical and midbrain 5HT, tryptophan and 5-hydroxyindoleacetic acid levels (measured by HPLC) were determined in twelve 5HTP treated and eight TCP treated rats, and compared with the values measured in 10 control, saline treated rats. Treatment with 5HTP significantly raised peripheral but not central 5HT concentrations. At adult age, peripheral 5HT homeostasis was re-established, while modest decrease in 5HT concentration was observed in frontal cortex, presumably due to hyperserotonemia-induced loss of 5HT terminals during brain development. Treatment with TCP induced significant 5HT elevations in both compartments. At adult age, permanent changes in 5HT homeostasis were observed, both peripherally (as hyperserotonemia) and centrally (as altered 5HT metabolism with decreased 5HT concentrations). Further studies are planned in order to explore the nature of the different disturbances of 5HT homeostasis induced by the two compounds, and their results are expected to shed some light on the role of hyperserotonemia in autism.
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PMID:The effects of the perinatal treatment with 5-hydroxytryptophan or tranylcypromine on the peripheral and central serotonin homeostasis in adult rats. 2167 93

Converging lines of evidence show that a sizable subset of autism-spectrum disorders (ASDs) is characterized by increased blood levels of serotonin (5-hydroxytryptamine, 5-HT), yet the mechanistic link between these two phenomena remains unclear. The enzymatic degradation of brain 5-HT is mainly mediated by monoamine oxidase (MAO)A and, in the absence of this enzyme, by its cognate isoenzyme MAOB. MAOA and A/B knockout (KO) mice display high 5-HT levels, particularly during early developmental stages. Here we show that both mutant lines exhibit numerous behavioural hallmarks of ASDs, such as social and communication impairments, perseverative and stereotypical responses, behavioural inflexibility, as well as subtle tactile and motor deficits. Furthermore, both MAOA and A/B KO mice displayed neuropathological alterations reminiscent of typical ASD features, including reduced thickness of the corpus callosum, increased dendritic arborization of pyramidal neurons in the prefrontal cortex and disrupted microarchitecture of the cerebellum. The severity of repetitive responses and neuropathological aberrances was generally greater in MAOA/B KO animals. These findings suggest that the neurochemical imbalances induced by MAOA deficiency (either by itself or in conjunction with lack of MAOB) may result in an array of abnormalities similar to those observed in ASDs. Thus, MAOA and A/B KO mice may afford valuable models to help elucidate the neurobiological bases of these disorders and related neurodevelopmental problems.
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PMID:Monoamine oxidase A and A/B knockout mice display autistic-like features. 2285 Apr 64


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