1. Hovde J, Kutscher EC. {{Autism and vaccinations: is there a correlation?}} {S D Med};2008 (Dec);61(12):456-457.
2. Luder AS, Mamet R, Farbstein I, Schoenfeld N. {{Awareness is the name of the game: clinical and biochemical evaluation of a case of a girl diagnosed with acute intermittent porphyria associated with autism}}. {Cell Mol Biol} (Noisy-le-grand);2009;55(1):19-22.
Neuroporphyrias, a heterogeneous group of metabolic diseases, are diagnosed less often than their true prevalence justifies. Lack of awareness of porphyrias and their protean clinical and biochemical manifestations, is the most significant hurdle to their recognition and diagnosis. These points are reflected in the unusual case reported here, which highlights the potential damage that inappropriate management may cause when the diagnosis is missed over a long period. We diagnosed heterozygous Acute Intermittent Porphyria (AIP) in a 15 yr old girl, who first presented with autism at the age of 4 years. This phenotypic association has not been previously reported. In addition to the unrecognized phenotype, her normal urinary aminolevulinic acid and porphobilinogen, findings which are not compatible with symptomatic porphyria according to well established criteria, could also have led to a missed diagnosis of neuroporphyria. However, the diagnosis of AIP was established on the basis of a 64% reduction in erythrocyte hydroxymethylbilane synthase (HMBS) activity and the finding of a known causative AIP mutation (p.D178N). We therefore recommend that porphyria should be considered in autistic children especially when there is an atypical course or unexpected abreaction to medications. The biochemical and genetic data should be carefully evaluated in a specialized porphyria center.
3. Newbury DF, Warburton PC, Wilson N, Bacchelli E, Carone S, Lamb JA, Maestrini E, Volpi EV, Mohammed S, Baird G, Monaco AP. {{Mapping of partially overlapping de novo deletions across an autism susceptibility region (AUTS5) in two unrelated individuals affected by developmental delays with communication impairment}}. {Am J Med Genet A};2009 (Mar 6)The International Molecular Genetic Study of Autism Consortium (IMGSAC)
Autism is a neurodevelopmental disorder characterized by deficits in reciprocal social interaction and communication, and repetitive and stereotyped behaviors and interests. Previous genetic studies of autism have shown evidence of linkage to chromosomes 2q, 3q, 7q, 11p, 16p, and 17q. However, the complexity and heterogeneity of the disorder have limited the success of candidate gene studies. It is estimated that 5% of the autistic population carry structural chromosome abnormalities. This article describes the molecular cytogenetic characterization of two chromosome 2q deletions in unrelated individuals, one of whom lies in the autistic spectrum. Both patients are affected by developmental disorders with language delay and communication difficulties. Previous karyotype analyses described the deletions as [46,XX,del(2)(q24.1q24.2)dn]. Breakpoint refinement by FISH mapping revealed the two deletions to overlap by approximately 1.1Mb of chromosome 2q24.1, a region which contains just one gene-potassium inwardly rectifying channel, subfamily J, member 3 (KCNJ3). However, a mutation screen of this gene in 47 autistic probands indicated that coding variants in this gene are unlikely to underlie the linkage between autism and chromosome 2q. Nevertheless, it remains possible that variants in the flanking genes may underlie evidence of linkage at this locus. (c) 2009 Wiley-Liss, Inc.
4. Olson CD. {{Does prenatal ultrasound increase risk of autism?}} {J Am Osteopath Assoc};2009 (Feb);109(2):71-72.
5. Pasca SP, Dronca E, Kaucsar T, Craciun EC, Endreffy E, Ferencz BK, Iftene F, Benga I, Cornean R, Banerjee R, Dronca M. {{One Carbon Metabolism Disturbances and the C667T MTHFR Gene Polymorphism in Children with Autism Spectrum Disorders}}. {J Cell Mol Med};2008 (Aug 9)
Autism spectrum disorders (ASDs), which include the prototypic autistic disorder (AD), Asperger’s syndrome (AS), and pervasive developmental disorders not otherwise specified (PDD-NOS) are complex neurodevelopmental conditions of unknown etiology. The current study investigated the metabolites in the methionine cycle, the transsulfuration pathway, folate, vitamin B(12) and the C677T polymorphism of the MTHFR gene in three groups of children diagnosed with AD (n=15), AS (n=5) and PDD-NOS (n=19) and their age and sex matched controls (n=25). No metabolic disturbances were seen in the AS patients, while in the AD and PDD-NOS groups, lower plasma levels of methionine (P=0.01 and P=0.03, respectively) and alpha-aminobutyrate were observed (P=0.01 and P=0.001, respectively). Only in the AD group, plasma cysteine (P=0.02) and total blood glutathione (P=0.02) were found to be reduced. Although there was a trend towards lower levels of serine, glycine, N, N-dimethylglycine in AD patients, the plasma levels of these metabolites as well as the levels of homocysteine and cystathionine were not statistically different in any of the ASDs groups. The serum levels of vitamin B(12) and folate were in the normal range. The results of the MTHFR gene analysis showed a normal distribution of the C677T polymorphism in children with ASDs, but the frequency of the 677T allele was slightly more prevalent in AD patients. Our study indicates a possible role for the alterations in one carbon metabolism in the pathophysiology of ASDs and provides, for the first time, preliminary evidence for metabolic and genetic differences between clinical subtypes of ASDs.
6. Sahyoun CP, Soulieres I, Belliveau JW, Mottron L, Mody M. {{Cognitive Differences in Pictorial Reasoning Between High-Functioning Autism and Asperger’s Syndrome}}. {J Autism Dev Disord};2009 (Mar 7)
We investigated linguistic and visuospatial processing during pictorial reasoning in high-functioning autism (HFA), Asperger’s syndrome (ASP), and age and IQ-matched typically developing participants (CTRL), using three conditions designed to differentially engage linguistic mediation or visuospatial processing (visuospatial, V; semantic, S; visuospatial + semantic, V + S). The three groups did not differ in accuracy, but showed different response time profiles. ASP and CTRL participants were fastest on V + S, amenable to both linguistic and nonlinguistic mediation, whereas HFA participants were equally fast on V and V + S, where visuospatial strategies were available, and slowest on S. HFA participants appeared to favor visuospatial over linguistic mediation. The results support the use of linguistic versus visuospatial tasks for characterizing subtypes on the autism spectrum.
7. Zecavati N, Spence SJ. {{Neurometabolic disorders and dysfunction in autism spectrum disorders}}. {Curr Neurol Neurosci Rep};2009 (Mar);9(2):129-136.
The cause of autism remains largely unknown because it is likely multifactorial, arising from the interaction of biologic, genetic, and environmental factors. The specific role of metabolic abnormalities also is largely unknown, but current research may provide insight into the pathophysiologic underpinnings of autism, at least in some patients. We review a number of known neurometabolic disorders identified as having an autistic phenotype. We also discuss the possible involvement of mitochondrial disorders and dysfunction as well as a theory regarding an increased vulnerability to oxidative stress, by which various environmental toxins produce metabolic alterations that impair normal cellular function. Finally, we review various strategies for metabolic work-up and treatment. Accurate diagnosis of neurometabolic disorders and a broader understanding of underlying metabolic disturbance even in the absence of known disease have important implications both for individual patients and for research into the etiology of autism.
