1. El-Ansary A, Al-Ayadhi L. {{Relative abundance of short chain and polyunsaturated fatty acids in propionic acid-induced autistic features in rat pups as potential markers in autism}}. {Lipids in health and disease}. 2014 Aug 31;13(1):140.
BACKGROUND: Fatty acids are essential dietary nutrients, and one of their important roles is providing polyunsaturated fatty acids (PUFAs) for the growth and function of nervous tissue. Short chain fatty acids (SCFAs) are a group of compounds derived from the host microbiome that were recently linked to effects on the gut, the brain, and behavior. They are therefore linked to neurodevelopmental disorders such as autism. Reduced levels of PUFAs are associated with impairments in cognitive and behavioral performance, which are particularly important during brain development. Recent studies suggest that omega -3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are involved in neurogenesis, neurotransmission, and protection from oxidative stress. Omega-3 PUFAs mediate some of these effects by antagonizing Omega-6 PUFA (arachidonic acid, AA)-induced proinflammatory prostaglandin E2 (PGE2) formation. METHODS: In this work, the absolute and relative concentrations of propionic (PPA), butyric and acetic acids, as well as PUFAs and their precursors (alpha-Linolenic and linoleic), were measured in the brain tissue of PPA-neurointoxicated rat pups (receiving 250 mg PPA/Kg body weight for 3 consecutive days) as a rodent model with persistent autistic features compared with healthy controls. RESULTS: The data revealed remarkably lower levels of omega6/omega3, alpha-Linolenic/Linoleic, alpha-Linolenic/EPA, alpha-Linolenic/DHA, EPA / DHA, and AA/Linoleic acid ratios in PPA-intoxicated rats. The role of these impaired ratios is discussed in relation to the activity of desaturases and elongases, which are the two enzymatic groups involved in the synthesis of PUFAs from their precursors. The relationship between the abnormal relative concentrations of the studied fatty acids and oxidative stress, neurotransmission, and neuroinflammation is also discussed in detail. CONCLUSIONS: This study demonstrates that fatty acid ratios are useful for understanding the mechanism of PPA neurotoxicity in a rodent model of autism. Therefore, it is possible to use these ratios for predictions in patients with this disorder.
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2. Handt M, Epplen A, Hoffjan S, Mese K, Epplen JT, Dekomien G. {{Point mutation frequency in the FMR1 gene as revealed by fragile X syndrome screening}}. {Molecular and cellular probes}. 2014 Aug 27.
Fragile X syndrome (FXS) is a common cause of intellectual disability, developmental delay and autism spectrum disorders. This syndrome is due to a functional loss of the FMR1 gene product FMRP, and, in most cases, it is caused by CGG repeat expansion in the FMR1 promoter. Yet, also other FMR1 mutations may cause a FXS-like phenotype. Since standard molecular testing does not include the analysis of the FMR1 coding region, the prevalence of point mutations causing FXS is not well known. Here, high resolution melting (HRM) was used to screen for FMR1 gene mutations in 508 males with clinical signs of mental retardation and developmental delay, but without CGG and GCC repeat expansions in the FMR1 gene and AFF2 genes, respectively. Sequence variations were identified by HRM analysis and verified by direct DNA sequencing. Two novel missense mutations (p.Gly482Ser in one patient and p.Arg534His in two unrelated patients), one intronic and two 3′-untranslated region (UTR) variations were identified in the FMR1 gene. Missense mutations in the FMR1 gene might account for a considerable proportion of cases in male patients with FXS-related symptoms, such as those linked to mental retardation and developmental delay.
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3. Oerlemans AM, Hartman CA, De Bruijn YG, Van Steijn DJ, Franke B, Buitelaar JK, Rommelse NN. {{Simplex and Multiplex Stratification in ASD and ADHD Families: A Promising Approach for Identifying Overlapping and Unique Underpinnings of ASD and ADHD?}}. {J Autism Dev Disord}. 2014 Aug 31.
Autism spectrum disorders (ASD) and attention-deficit/hyperactivity disorder (ADHD) are highly heterogeneous neuropsychiatric disorders, that frequently co-occur. This study examined whether stratification into single-incidence (SPX) and multi-incidence (MPX) is helpful in (a) parsing heterogeneity and (b) detecting overlapping and unique underpinnings of the disorders. ASD and ADHD traits were measured in 56 ASD/31 ADHD SPX families, 59 ASD/171 ADHD MPX families and 203 control families. In ASD but not ADHD, behavioral traits were less elevated in SPX than MPX unaffected relatives, suggesting that SPX-MPX stratification may thus help parse ASD, but not ADHD heterogeneity. Particularly unaffected relatives from MPX ASD/ADHD families displayed elevated trait levels of both disorders, indicating shared (multifactorial) underpinnings underlying ASD and ADHD in these families. Cross-disorder traits were highest in MPX ASD unaffected siblings.
