Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Autism is a poorly understood developmental disorder characterized by social impairment, communication deficits, and compulsive behavior. The authors review evidence from animal studies demonstrating that the nonapeptides, oxytocin and vasopressin, have unique effects on the normal expression of species-typical social behavior, communication, and rituals. Based on this evidence, they hypothesize that an abnormality in oxytocin or vasopressin neurotransmission may account for several features of autism. As autism appears to be a genetic disorder, mutations in the various peptide, peptide receptor, or lineage-specific developmental genes could lead to altered oxytocin or vasopressin neurotransmission. Many of these genes have been cloned and sequenced, and several polymorphisms have been identified. Recent gene targeting studies that alter expression of either the peptides or their receptors in the rodent brain partially support the autism hypothesis. While previous experience suggests caution in hypothesizing a cause or suggesting a treatment for autism, the available preclinical evidence with oxytocin and vasopressin recommends the need for clinical studies using gene scanning, pharmacological and neurobiological approaches.
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PMID:Oxytocin, vasopressin, and autism: is there a connection? 995 61

The etiology of autism is complex, and in most cases the underlying pathologic mechanisms are unknown. Autism is a hetereogeneous disorder, diagnosed subjectively on the basis of a large number of criteria. Recent research has investigated genetics, in utero insults and brain function as well as neurochemical and immunological factors. On the basis of family and twin studies, there appears to be a genetic basis for a wide "autistic syndrome." About a quarter of cases of autism are associated with genetic disorders such as fragile X syndrome or with infectious diseases such as congenital rubella. Genetic studies have shown an association between autism markers of brain development such as 3 markers of the c-Harvey-ros oncogene and the homeobox gene EN2. In some cases, autism is associated with insults early in gestation, including thalidomide embryopathy. Autism may arise from abnormal central nervous system functioning, since most autistic patients have indications of brain dysfunction, and about half of them have abnormal electroencephalograms. Similarly, the pattern of evoked response potentials and conduction time is altered in autistic children. There is substantial evidence from neuroimaging studies that dysfunctions in the cerebellum and possibly the temporal lobe and association cortex occur in autistic symptoms. Neurochemical studies have investigated the role of serotonin, epinephrine and norepinephrine, since levels of these neurotransmitters are altered in autism, although other hypotheses implicate overactive brain opioid systems and changes in oxytocin neurotransmission. Autoimmunity may also play a role; antibodies against myelin basic protein are often found in children with autism, who also have increased eosinophil and basophil response to IgE-mediated reactions. In summary, the prevailing view is that autism is caused by a pathophysiologic process arising from the interaction of an early environmental insult and a genetic predisposition.
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PMID:Etiology of infantile autism: a review of recent advances in genetic and neurobiological research. 1021 50

Autism is a neurodevelopmental disorder characterized by dysfunction in three core behavioral domains: repetitive behaviors, social deficits, and language abnormalities. There is evidence that abnormalities exist in peptide systems, particularly the oxytocin system, in autism spectrum patients. Furthermore, oxytocin and the closely related peptide vasopressin are known to play a role in social and repetitive behaviors. This study examined the impact of oxytocin on repetitive behaviors in 15 adults with autism or Asperger's disorder via randomized double-blind oxytocin and placebo challenges. The primary outcome measure was an instrument rating six repetitive behaviors: need to know, repeating, ordering, need to tell/ask, self-injury, and touching. Patients with autism spectrum disorders showed a significant reduction in repetitive behaviors following oxytocin infusion in comparison to placebo infusion. Repetitive behavior in autism spectrum disorders may be related to abnormalities in the oxytocin system, and may be partially ameliorated by synthetic oxytocin infusion.
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PMID:Oxytocin infusion reduces repetitive behaviors in adults with autistic and Asperger's disorders. 1249 56

Oxytocin plays an important role in social-affiliative behaviors. It has been proposed that exposure to high levels of exogenous oxytocin at birth, via pitocin induction of delivery, might increase susceptibility to autism by causing a downregulation of oxytocin receptors in the developing brain. This study examined the rates of labor induction using pitocin in children with autism and matched controls with either typical development or mental retardation. Birth histories of 41 boys meeting the criteria for autistic disorder were compared to 25 age- and IQ-matched boys without autism (15 typically developing and 10 with mental retardation). There were no differences in pitocin induction rates as a function of either diagnostic group (autism vs. control) or IQ level (average vs. subaverage range), failing to support an association between exogenous exposure to oxytocin and neurodevelopmental abnormalities.
J Autism Dev Disord 2003 Apr
PMID:Brief report: pitocin induction in autistic and nonautistic individuals. 1275 61

Objective of the study was to replicate in adults our previous findings of decreased heart rate and normal endocrine responses to stress in autistic children and to elucidate the discrepancy between autonomic and endocrine stress responses by including epinephrine, norepinephrine, oxytocin and vasopressin measurements. Ten autistic spectrum disorder (ASD) adults were compared to 14 healthy controls in their response to a psychosocial stressor (public speaking). ASD patients showed decreased heart rate, but normal cortisol responses, consistent with our prior findings in children. No differences in norepinephrine, epinephrine, oxytocin or vasopressin responses to stress were found. However, in contrast to previous findings in low functioning autistic children, ASD adults showed increased basal oxytocin levels, which may be related to developmental factors.
J Autism Dev Disord 2006 Oct
PMID:Autonomic and neuroendocrine responses to a psychosocial stressor in adults with autistic spectrum disorder. 1686 50

Autism spectrum disorders (ASD) are male-biased and characterized by deficits in social behavior and social communication, excessive anxiety or hyperreactivity to stressful experiences, and a tendency toward repetitiveness. The purpose of this review is to consider evidence for a role for two sexually dimorphic neuropeptides, oxytocin (OT) and arginine vasopressin (VP), in these features of ASD. Both VP and OT play a role in normal development. VP is androgen-dependent and of particular importance to male behavior. Excess VP or disruptions in the VP system could contribute to the male vulnerability to ASD. Alternatively, protective processes mediated via OT or the OT receptor might help to explain the relatively rare occurrence of ASD in females. Disruptions in either OT or VP or their receptors could result from genetic variation or epigenetic modifications of gene expression, especially during early development. Deficits in other developmental growth factors, such as reelin, which may in turn regulate or be regulated by OT or VP, are additional candidates for a role in ASD.
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PMID:Sex differences in oxytocin and vasopressin: implications for autism spectrum disorders? 1700 15

Autism is a developmental disorder characterized by three core symptom domains: speech and communication abnormalities, social functioning impairments and repetitive behaviours and restricted interests. Oxytocin (OXT) is a nine-amino-acid peptide that is synthesized in the paraventricular and supraoptic nucleus of the hypothalamus and released into the bloodstream by axon terminals in the posterior pituitary where it plays an important role in facilitating uterine contractions during parturition and in milk let-down. In addition, OXT and the structurally similar peptide arginine vasopressin (AVP) are released within the brain where they play a key role in regulating affiliative behaviours, including sexual behaviour, mother-infant and adult-adult pair-bond formation and social memory/recognition. Finally, OXT has been implicated in repetitive behaviours and stress reactivity. Given that OXT is involved in the regulation of repetitive and affiliative behaviours, and that these are key features of autism, it is believed that OXT may play a role in autism and that OXT may be an effective treatment for these two core symptom domains. In this chapter we review evidence to date supporting a relationship between OXT and autism; we then discuss research looking at the functional role of OXT in autism, as well as a pilot study investigating the therapeutic efficacy of OXT in treating core autism symptom domains. Finally, we conclude with a discussion of directions for future research.
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PMID:Oxytocin and experimental therapeutics in autism spectrum disorders. 1865 1

Genetic studies of autism spectrum conditions (ASC) have mostly focused on the "low functioning" severe clinical subgroup, treating it as a rare disorder. However, ASC is now thought to be relatively common ( approximately 1%), and representing one end of a quasi-normal distribution of autistic traits in the general population. Here we report a study of common genetic variation in candidate genes associated with autistic traits and Asperger syndrome (AS). We tested single nucleotide polymorphisms in 68 candidate genes in three functional groups (sex steroid synthesis/transport, neural connectivity, and social-emotional responsivity) in two experiments. These were (a) an association study of relevant behavioral traits (the Empathy Quotient (EQ), the Autism Spectrum Quotient (AQ)) in a population sample (n=349); and (b) a case-control association study on a sample of people with AS, a "high-functioning" subgroup of ASC (n=174). 27 genes showed a nominally significant association with autistic traits and/or ASC diagnosis. Of these, 19 genes showed nominally significant association with AQ/EQ. In the sex steroid group, this included ESR2 and CYP11B1. In the neural connectivity group, this included HOXA1, NTRK1, and NLGN4X. In the socio-responsivity behavior group, this included MAOB, AVPR1B, and WFS1. Fourteen genes showed nominally significant association with AS. In the sex steroid group, this included CYP17A1 and CYP19A1. In the socio-emotional behavior group, this included OXT. Six genes were nominally associated in both experiments, providing a partial replication. Eleven genes survived family wise error rate (FWER) correction using permutations across both experiments, which is greater than would be expected by chance. CYP11B1 and NTRK1 emerged as significantly associated genes in both experiments, after FWER correction (P<0.05). This is the first candidate-gene association study of AS and of autistic traits. The most promising candidate genes require independent replication and fine mapping.
Autism Res 2009 Jun
PMID:Genes related to sex steroids, neural growth, and social-emotional behavior are associated with autistic traits, empathy, and Asperger syndrome. 1959 35

An increasing number of animal studies advert to a substantial role of the neuropeptide oxytocin in the regulation of social attachment and affiliation. Furthermore, animal studies showed anxiety and stress-reduced effects of oxytocin. First human studies confirm these findings in animal studies and implicate a crucial role of oxytocin in human social attachment behavior and in social interactions. Thus, the oxytocin system might be involved in the impairment of social interaction and attachment in autism spectrum disorders (ASD). The human oxytocin receptor gene (OXTR) represents a plausible candidate gene for the etiology of ASD. To analyze whether genetic variants in the OXTR gene are associated with ASD we performed family-based single-marker and haplotype association analyses with 22 single nucleotide polymorphisms (SNPs) in the OXTR and its 5' region in 100 families with autistic disorders on high-functioning level (Asperger syndrome (AS), high-functioning autism (HFA), and atypical autism (AA)). Single-marker and haplotype association analyses revealed nominally significant associations of one single SNP and one haplotype with autism, respectively. Furthermore, employing a "reverse phenotyping" approach, patients carrying the haplotype associated with autism showed nominally significant impairments in comparison to noncarriers of the haplotype in items of the Autism Diagnostic Interview-Revised algorithm describing aspects of social interaction and communication. In conclusion, our results implicate that genetic variation in the OXTR gene might be relevant in the etiology of autism on high-functioning level.
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PMID:Evidence for the involvement of genetic variation in the oxytocin receptor gene (OXTR) in the etiology of autistic disorders on high-functioning level. 1977 62

The neurobiological basis of autism spectrum disorder (ASD) remains poorly understood. Given the role of CD38 in social recognition through oxytocin (OT) release, we hypothesized that CD38 may play a role in the etiology of ASD. Here, we first examined the immunohistochemical expression of CD38 in the hypothalamus of post-mortem brains of non-ASD subjects and found that CD38 was colocalized with OT in secretory neurons. In studies of the association between CD38 and autism, we analyzed 10 single nucleotide polymorphisms (SNPs) and mutations of CD38 by re-sequencing DNAs mainly from a case-control study in Japan, and Caucasian cases mainly recruited to the Autism Genetic Resource Exchange (AGRE). The SNPs of CD38, rs6449197 (p<0.040) and rs3796863 (p<0.005) showed significant associations with a subset of ASD (IQ>70; designated as high-functioning autism (HFA)) in the U.S. 104 AGRE family trios, but not with Japanese 188 HFA subjects. A mutation that caused tryptophan to replace arginine at amino acid residue 140 (R140W; (rs1800561, 4693C>T)) was found in 0.6-4.6% of the Japanese population and was associated with ASD in the smaller case-control study. The SNP was clustered in pedigrees in which the fathers and brothers of T-allele-carrier probands had ASD or ASD traits. In this cohort OT plasma levels were lower in subjects with the T allele than in those without. One proband with the T allele who was taking nasal OT spray showed relief of symptoms. The two variant CD38 poloymorphysms tested may be of interest with regard of the pathophysiology of ASD.
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PMID:Two genetic variants of CD38 in subjects with autism spectrum disorder and controls. 2043 66


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