Clinical Studies | Autism Disorders


CLINICAL STUDY 1 — A Case of Autism with an Interstitial Deletion on 4q Leading to Hemizygosity for Genes Encoding for Glutamine and Glycine Neurotransmitter Receptor Sub-units (AMPA 2, GLRA3, GLRB) and Neuropeptide Receptors NPY1R, NPY5R

—Ramanathan S, Woodroffe A, Flodman PL, Mays LZ, Hanouni M, Modahl CB, Steinberg-Epstein R, Bocian ME, Spence MA, Smith M. – Department of Pediatrics, University of California, Irvine, Irvine, CA, USA

BACKGROUND: Autism is a pervasive developmental disorder characterized by a triad of deficits: qualitative impairments in social interactions, communication deficits, and repetitive and stereotyped patterns of behavior. Although autism is etiologically heterogeneous, family and twin studies have established a definite genetic basis. The inheritance of idiopathic autism is presumed to be complex, with many genes involved; environmental factors are also possibly contributory. The analysis of chromosome abnormalities associated with autism contributes greatly to the identification of autism candidate genes. CASE PRESENTATION: We describe a child with autistic disorder and an interstitial deletion on chromosome 4q. This child first presented at 12 months of age with developmental delay and minor dysmorphic features. At 4 years of age a diagnosis of Pervasive Developmental Disorder was made. At 11 years of age he met diagnostic criteria for autism. Cytogenetic studies revealed a chromosome 4q deletion. The karyotype was 46, XY del 4 (q31.3-q33). Here we report the clinical phenotype of the child and the molecular characterization of the deletion using molecular cytogenetic techniques and analysis of polymorphic markers. These studies revealed a 19 megabase deletion spanning 4q32 to 4q34. Analysis of existing polymorphic markers and new markers developed in this study revealed that the deletion arose on a paternally derived chromosome. To date 33 genes of known or inferred function are deleted as a consequence of the deletion. Among these are the AMPA 2 gene that encodes the glutamate receptor GluR2 sub-unit, GLRA3 and GLRB genes that encode glycine receptor subunits and neuropeptide Y receptor genes NPY1R and NPY5R. CONCLUSIONS: The deletion in this autistic subject serves to highlight specific autism candidate genes. He is hemizygous for AMPA 2, GLRA3, GLRB, NPY1R and NPY5R. GluR2 is the major determinant of AMPA receptor structure. Glutamate receptors maintain structural and functional plasticity of synapses. Neuropeptide Y and its receptors NPY1R and NPY5R play a role in hippocampal learning and memory. Glycine receptors are expressed in very early cortical development. Molecular cytogenetic studies and DNA sequence analysis in other patients with autism will be necessary to confirm that these genes are involved in autism. PMID: 15090072

CLINICAL STUDY 2 — Decreased Beta-Phenylethylamine in Urine of Children with Attention Deficit Hyperactivity Disorder and Autistic Disorder

—Kusaga A. – Department of Pediatrics and Child Health, Kurume University School of Medicine, Kurume, Fukuoka

Beta-phenylethylamine (PEA), a biogenic trace amine, acts as a neuromodulator in the nigrostriatal dopaminergic pathway and stimulates the release of dopamine. To clarify the mechanism of neurochemical metabolism in attention deficit hyperactivity disorder (ADHD), we measured the urine levels of PEA using gas chromatography-chemical ionization-mass spectrometry. The urinary levels of 3-methoxy-4-hydroxyphenyl glycol (MHPG), homovanillic acid (HVA), and 5-hydroxy-indoleacetic acid (5-HIAA) were determined by high performance liquid chromatography. Urine samples were collected in a 24 hour period. Findings were compared with those obtained from controls (N = 15), children with ADHD (N = 15), and children with autistic disorder (AD) (N = 5). The mean urinary levels of MHPG, HVA, and 5-HIAA in the children with ADHD were not significantly different from those of the controls or those with AD, whereas PEA levels were significantly lower in children with ADHD (11.23 +/- 13.40 micrograms/g creatinine) compared with controls (56.01 +/- 52.18 micrograms/g creatinine). PEA and MHPG levels in children with AD (14.75 +/- 14.37 micrograms/g creatine, 1.10 +/- 0.61 micrograms/mg creatine, respectively) were significantly decreased compared to controls (MHPG, 2.2 +/- 0.9 micrograms/mg creatine). The decreased urine PEA in children with ADHD and AD may suggest a common underlying pathophysiology. The decreased urine MHPG in children with AD might indicate the existence of an alteration in central and peripheral noradrenergic function. PMID: 12030014

CLINICAL STUDY 3 — Substitutive and Dietetic Approaches in Childhood Autistic Disorder: Interests and Limits

—Hjiej H, Doyen C, Couprie C, Kaye K, Contejean Y. – Service de psychopathologie de l’enfant et de l’adolescent, centre hospitalier Sainte-Anne, Paris, France

INTRODUCTION: Autism is a developmental disorder that requires specialized therapeutic approaches. Influenced by various theoretical hypotheses, therapeutic programs are typically structured on a psychodynamic, biological or educative basis. Presently, educational strategies are recommended in the treatment of autism, without excluding other approaches when they are necessary. Some authors recommend dietetic or complementary approaches to the treatment of autism, which often stimulates great interest in the parents but also provokes controversy for professionals. Nevertheless, professionals must be informed about this approach because parents are actively in demand of it. LITERATURE FINDINGS: First of all, enzymatic disorders and metabolic errors are those most frequently evoked in the literature. The well-known phenylalanine hydroxylase deficit responsible for phenylketonuria has been described as being associated with autism. In this case, adapted diet prevents mental retardation and autistic symptoms. Some enzymatic errors are also corrected by supplementation with uridine or ribose for example, but these supplementations are the responsibility of specialized medical teams in the domain of neurology and cannot be applied by parents alone. Secondly, increased opoid activity due to an excess of peptides is also supposed to be at the origin of some autistic symptoms. Gluten-free or casein-free diets have thus been tested in controlled studies, with contradictory results. With such diets, some studies show symp regression but others report negative side effects, essentially protein malnutrition. Methodological bias, small sample sizes, the use of various diagnostic criteria or heterogeneity of evaluation interfere with data analysis and interpretation, which prompted professionals to be cautious with such diets. The third hypothesis emphasized in the literature is the amino acid domain. Some autistic children lack some amino acids such as glutamic or aspartic acids for example and this deficiency would create autistic symptoms. However, for some authors, these deficits are attributed to nutritional deficits caused by the food selectivity of children. A fourth hypothesis concerning metabolic implication in autism is the suspicion that a food allergy phenomenon could interfere with development, and it has been observed that Ig levels are higher in autistic children than in control children. Autistic children with a positive reaction to food Ig would have a more favorable outcome with diet excluding some kinds of food; but most of those diets are drastic and ethically debatable. Fifth, glucidic catabolism could be deleterious with an excess of ketonic products that will initiate comitial seizures. Few studies with ketogenic diet have been conducted but, as it has been described with epileptic subjects, those diets would diminish autistic symptoms. Not enough studies have been conducted that would allow one to draw any firm conclusions. The sixth hypothesis is linked with vitamin deficiencies that are a notably important area of research in the treatment of autism. Vitamin B12 or B6 deficiencies have been studied in several articles, and many of them were controlled studies. French teams also emphasize an interest in supplementation with B12 or B6. The two last hypotheses concern auto-immune patterns and the toxic effects of heavy metals like mercury. There is a paucity of methodologically satisfying studies that support these two hypotheses and diet recommendations. Following these assumptions, some dietetic approaches have been recommended, even though the methodological aspects of supporting studies are poor. The most famous diet is the gluten-free and/or casein-free diet. Only two controlled studies attracted our attention. Even if for some autistic children such a diet was positive, for others, gluten-free or casein-free diets were poorly tolerated and, for some authors, not without considerable side effects, the more prejudicial of which was the Kwashiorkor risk. Ketogenic diets have been studied in

one non controlled study, but even if positive results have been noted by the authors, the ketogenic diet is very restricting and the long term effects have not been evaluated. Vitamin supplementation is the one and only diet domain where there have been many repeated and placebo-controlled studies. Side effects are rare and mild even if high doses of vitamin B6 are advocated in these studies. In total, as evoked by Rimland, 11 controlled placebo-blind studies have been conducted and 50% of autistic children with this supplementation had improved autistic signs. However, these results still remain debated. Finally, more rarely, enzymatic abnormalities need specific diets which have some positive consequences, but such diets could not be applied by parents alone and are the responsibility of specialized teams. For discussion purposes we can emphasize that, in spite of the amount of studies concerning the effects of specialized diets, few are methodologically satisfying. We cannot ignore that some side effects are possible with such approaches and parents need to be informed of them. Some are even potentially serious, such as diets with metal chelators. In spite of those results, vitamin supplementation seems to be the only one that some specialized teams in autism could apply, always with parent agreement. In conclusion, within this scientific field, studies on eating habits of autistic children should be conducted because of their food selectivity or avoidance. PMID: 19068339

CLINICAL STUDY 4 — Combined Vitamin B6-Magnesium Treatment in Autism Spectrum Disorder

—Nye C, Brice A. – UCF Center for Autism & Related Disabilities, Orlando, Florida, USA

BACKGROUND: The use of mega-vitamin intervention began in the 1950s with the treatment of schizophrenic patients. Pyroxidine (vitamin B6) was first used with children diagnosed with “autism syndrome” when speech and language improvement was observed in some children as a result of large doses of B6. A number of studies attempted to assess the effects of vitamin B6-magnesium (Mg) was found to reduce undesirable side effects from B6) on characteristics such as verbal communication, non-verbal communication, interpersonal skills, and physiological function, in individuals with autism. OBJECTIVES: To determine the efficacy of vitamin B6 and magnesium (B6-Mg) for treating social, communication, and behavioural responses of children and adults with autism. SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register (Cochrane Library, Issue 2, 2002), MEDLINE (1966 to January 2002), EMBASE (1980 to January 2002), PsycINFO (1887 to January 2002), and Dissertation Abstracts International (1861 to January 2002). The search engine FirstSearch was also used (January 2002). All searches were updated in April 2005. Reference lists for all the obtained studies and other review articles were examined for additional studies. SELECTION CRITERIA: All studies in which the participants had been diagnosed with autistic spectrum disorder were randomly allocated prior to intervention and in which outcomes were compared to either a placebo or non-treated group were included. DATA COLLECTION AND ANALYSIS: Two reviewer’s independently evaluated and extracted data from all potential studies identified for inclusion. MAIN RESULTS: This update includes a new trial (Kuriyama 2002) to bring the total of included studies to three (total n=33). One study, which used a cross-over design (Tolbert 1993), provided insufficient data to conduct an analysis. Another crossover study (Findling 1997) yielded no significant differences between treatment and placebo group performances following the B6 intervention on measures of social interaction, communication, compulsivity, impulsivity, or hyperactivity. The latest study (Kuriyama 2002) was motivated by evidence from epilepsy research and was focused on a subgroup of children with pervasive developmental disorders (PDDs) who exhibited clinical features similar to those with pyroxidine-dependent epilepsy. This small study (n=8) only measured IQ and ‘Social Quotient’ and found a statistically significant benefit for IQ (5.2, 95% CI = [0.2 to 10.3]) when in the treated group, by using change scores. AUTHORS’ CONCLUSIONS: Due to the small number of studies, the methodological quality of studies, and small sample sizes, no recommendation can be advanced regarding the use of B6-Mg as a treatment for autism PMID: 16235322

CLINICAL STUDY 5 — Increased Presynaptic Dopamine Function in Asperger Syndrome

—Nieminen-von Wendt TS, Metsähonkala L, Kulomäki TA, Aalto S, Autti TH, Vanhala R, Eskola O, Bergman J, Hietala JA, von Wendt LO. – Department of Child Neurology, Hospital for Children and Adolescents, Helsinki University Central Hospital, PL 280, FIN-00029 HYKS, Helsinki, Finland

The etiology of Asperger syndrome is essentially unknown, but abnormality of the dopamine system has been shown in clinically overlapping disorders. The present study was designed to investigate the presynaptic dopamine function in Asperger syndrome. Eight healthy, drug-free males with Asperger syndrome and five healthy male controls were examined with positron emission ography using 6 – fluoro-l-dopa (f-dopa) as a tracer. In the Asperger syndrome group, the f-dopa influx (Ki) values were increased in the striatum, i.e. in the putamen and caudate nucleus and in the frontal cortex. The results indicate that the dopamine system is affected in subjects with Asperger syndrome. Partially similar results have also been obtained in schizophrenia, suggesting an overlap not only of the clinical features but also of pathogenesis. PMID: 15073509

(phenylalanine is the precursor to tyrosine, which in turn is the precursor to l-dopa)

CLINICAL STUDY 6 — Neuroimaging and Neurochemical Studies of Rett Syndrome

—Matuishi T, Yamashita Y. – Department of Pediatrics and Child Health, Kurume University School of Medicine, Kurume

We review here the current status of neuroimaging and neurochemical research on Rett syndrome (RTT), with reference to neurophysiological, neuropathological, and immuno-histochemical changes previously described. Abnormalities have been reported in the intermediates of the biogenic amine neurotransmitters/receptor systems, and of beta-phenylethylamine (PEA), an endogenous amine synthesized by the decarboxylation of phenylalanine in dopaminergic neurons of the nigrostratal system. We also discuss the roles of other neurotransmitters including beta-endrophin, substance P and neurotrophic factors including nerve growth factors. Recently, mutations in the gene encoding methyl-CpG binding protein 2 (MeCP2), mapped to Xq28, have been identified in patients with RTT. Multiple abnormalities in various neurotransmitter/receptor systems may accounts for the pervasive defects in RTT. PMID: 12030008

CLINICAL STUDY 7 — Micronutrients versus standard medication management in autism

—Mehl-Madrona, L., Leung, B., Kennedy, C., Paul, S., Kaplan, B.J. (2010). Journal of Child and Adolescent Psychopharmacology. 20(2): 95-103

Autism spectrum disorder (ASD) is often accompanied by self-injurious behavior (SIB), aggression, and tantrums, symptoms that have reportedly improved with micronutrient (vitamins and minerals) treatment. The current study took advantage of naturally occurring differences in parental preferences for treatment approaches. The micronutrient group asked for treatment without pharmaceuticals (n = 44, aged 2-28 years at entry [M = 8.39 +/- 5.58]). Their records were matched with those of 44 similar children whose families requested conventional treatment (medication group). Both groups improved on both the Childhood Autism Rating Scale and the Childhood Psychiatric Rating Scale (all p values <0.0001). Both groups also exhibited significant decreases in total Aberrant Behavior Checklist scores, but the micronutrient group’s improvement was significantly greater (p < 0.0001). SIB Intensity was lower in the micronutrient group at the end of the study (p = 0.005), and improvement on the Clinical Global Impressions scale was greater for the micronutrient group (p = 0.0029). It is difficult to determine whether the observed changes were exerted through improvement in mood disorder or through an independent effect on autistic disorder. There were some advantages to treatment with micronutrients-lower activity level, less social withdrawal, less anger, better spontaneity with the examiner, less irritability, lower intensity SIB, markedly fewer adverse events, and less weight gain. Advantages of medication management were insurance coverage, fewer pills, and less frequent dosing. PMID: 20415604

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