The invasive twospot livebearer's biology, and its current and potential global distribution.

Poeciliids are widely recognized as successful invaders, possessing traits associated with invasion success. Native to Central America and south-eastern Mexico, the twospot livebearer (Pseudoxiphophorus bimaculatus) is a species recently recognized as invasive in both Central and northern Mexico. Despite its invasive status, limited research exists on its invasion process and the potential threats it poses to native species. In this study, we conducted a comprehensive review of the current knowledge on the twospot livebearer and mapped its current and potential distribution worldwide. The twospot livebearer shares similar traits with other successful invaders within the same family. Notably, it exhibits high fecundity throughout the year and demonstrates resilience to highly polluted and oxygen-deprived water conditions. This fish serves as a host for several parasites, including generalists, and has been extensively translocated for commercial purposes. Recently, it has also been used for biocontrol within its native range. Apart from existing outside its native range, the twospot livebearer, under current climate conditions and if transported there, could readily colonize biodiversity hotspots in tropical zones worldwide, including the Caribbean Islands, the Horn of Africa, North of Madagascar Island, south-eastern Brazil, and others located in southern and eastern Asia. Given that this fish is highly plastic and our Species Distribution Model, we consider that all areas with a habitat suitability >0.2 should prevent its arrival and establishment. Our findings underscore the urgent need to recognize this species as a threat to freshwater native topminnows and prevent its introduction and spread.

Asperger syndrome: can the disorder be diagnosed in the adult age?

INTRODUCTION: Asperger Syndrome (AS) is characterized by a qualitative disorder of social interaction, a pattern of restrictive, repetitive and stereotyped behavior, interests and activities, with normal intellectual capacity and normal language skills in the areas of grammar and vocabulary. Since its inclusion in international taxonomies, there has been much controversy regarding its nosological validity. CLINICAL CASE: A patient with a diagnosis of AS in adulthood is described. Results from the psychopathological, personality and cognitive functioning assessment are included. CONCLUSIONS: Asperger Syndrome can also be diagnosed in adulthood and should be suspected whenever retrospective information and clinical assessment point to this diagnosis.

Increased subcortical neural responses to repeating auditory stimulation in children with autism spectrum disorder.

Recent research has highlighted atypical reactivity to sensory stimulation as a core symptom in children with autism spectrum disorder (ASD). However, little is known about the dysfunctional neurological mechanisms underlying these aberrant sensitivities. Here we tested the hypothesis that the ability to filter out auditory repeated information is deficient in children with ASD already from subcortical levels, yielding to auditory sensitivities. We recorded the frequency-following response (FFR), a non-invasive measure of the neural tracking of the periodic characteristics of a sound in the subcortical auditory system, to compare repetition-related effects in children with ASD and typically developing children. Results revealed an increase of the FFR with stimulus repetition in children with ASD compared to their peers. Moreover, such defective early sensory encoding of stimulus redundancy was associated with sensory overload. These results highlight that auditory sensitivities in ASD emerge already at the level of the subcortical auditory system.

Involvement of the 14-3-3 Gene Family in Autism Spectrum Disorder and Schizophrenia: Genetics, Transcriptomics and Functional Analyses.

The 14-3-3 protein family are molecular chaperones involved in several biological functions and neurological diseases. We previously pinpointed YWHAZ (encoding 14-3-3ζ) as a candidate gene for autism spectrum disorder (ASD) through a whole-exome sequencing study, which identified a frameshift variant within the gene (c.659-660insT, p.L220Ffs*18). Here, we explored the contribution of the seven human 14-3-3 family members in ASD and other psychiatric disorders by investigating the: (i) functional impact of the 14-3-3ζ mutation p.L220Ffs*18 by assessing solubility, target binding and dimerization; (ii) contribution of common risk variants in 14-3-3 genes to ASD and additional psychiatric disorders; (iii) burden of rare variants in ASD and schizophrenia; and iv) 14-3-3 gene expression using ASD and schizophrenia transcriptomic data. We found that the mutant 14-3-3ζ protein had decreased solubility and lost its ability to form heterodimers and bind to its target tyrosine hydroxylase. Gene-based analyses using publicly available datasets revealed that common variants in YWHAE contribute to schizophrenia (p = 6.6 × 10-7), whereas ultra-rare variants were found enriched in ASD across the 14-3-3 genes (p = 0.017) and in schizophrenia for YWHAZ (meta-p = 0.017). Furthermore, expression of 14-3-3 genes was altered in post-mortem brains of ASD and schizophrenia patients. Our study supports a role for the 14-3-3 family in ASD and schizophrenia.

Paternally inherited cis-regulatory structural variants are associated with autism.

The genetic basis of autism spectrum disorder (ASD) is known to consist of contributions from de novo mutations in variant-intolerant genes. We hypothesize that rare inherited structural variants in cis-regulatory elements (CRE-SVs) of these genes also contribute to ASD. We investigated this by assessing the evidence for natural selection and transmission distortion of CRE-SVs in whole genomes of 9274 subjects from 2600 families affected by ASD. In a discovery cohort of 829 families, structural variants were depleted within promoters and untranslated regions, and paternally inherited CRE-SVs were preferentially transmitted to affected offspring and not to their unaffected siblings. The association of paternal CRE-SVs was replicated in an independent sample of 1771 families. Our results suggest that rare inherited noncoding variants predispose children to ASD, with differing contributions from each parent.

Common and rare variants of microRNA genes in autism spectrum disorders.

OBJECTIVES: MicroRNAs (miRNAs) are post-transcriptional regulators that have been shown to be involved in disease susceptibility. Here we explore the possible contribution of common and rare variants in miRNA genes in autism spectrum disorders (ASD). METHODS: A total of 350 tag SNPs from 163 miRNA genes were genotyped in 636 ASD cases and 673 controls. A replication study was performed in a sample of 449 ASD cases and 415 controls. Additionally, rare variants in 701 miRNA genes of 41 ASD patients were examined using whole-exome sequencing. RESULTS: The most significant association in the discovery sample was obtained for the miR-133b/miR-206 cluster (rs16882131, P = 0.00037). The replication study did not reach significance. However, the pooled analysis (1,085 cases and 1,088 controls) showed association with two miRNA clusters: miR-133b/miR-206 (rs16882131, permP = 0.037) and miR-17/miR-18a/miR-19a/miR-20a/miR-19b-1/miR92a-1 (rs6492538, permP = 0.019). Both miR-133b and miR-206 regulate the MET gene, previously associated with ASD. Rare variant analysis identified mutations in several miRNA genes, among them miR-541, a brain-specific miRNA that regulates SYN1, found mutated in ASD. CONCLUSIONS: Although our results do not establish a clear role for miRNAs in ASD, we pinpointed a few candidate genes. Further exome and GWAS studies are warranted to get more insight into their potential contribution to the disorder.

Contribution of common and rare variants of the PTCHD1 gene to autism spectrum disorders and intellectual disability.

Recent findings revealed rare copy number variants and missense changes in the X-linked gene PTCHD1 in autism spectrum disorder (ASD) and intellectual disability (ID). Here, we aim to explore the contribution of common PTCHD1 variants in ASD and gain additional evidence for the role of rare variants of this gene in ASD and ID. A two-stage case-control association study investigated 28 tag single nucleotide polymorphisms (SNPs) in 994 ASD cases and 1035 controls from four European populations. Mutation screening was performed in 673 individuals who included 240 ASD cases, 183 ID patients and 250 controls. The case-control association study showed a significant association with rs7052177 (P=6.13E-4) in the ASD discovery sample that was replicated in an independent sample (P=0.03). A Mantel-Haenszel meta-analysis for rs7052177T considering the four European populations showed an odds ratio of 0.58 (P=7E-05). This SNP is predicted to be located in a transcription factor binding site. No rare missense PTCHD1 variants were found in our ASD cohort and only one was identified in the ID sample. A duplication (27 bp) in the promoter region, absent from 590 controls, was found in three ASD patients (Fisher exact test, P=0.024). A gene reporter assay showed a significant decrease in the transcriptional activity (26%) driven by this variant. Moreover, we found that the longest allele of a trinucleotide repeat located upstream from PTCHD1 was associated with ASD (P=0.003, permP=0.0186). Our results further support the involvement of PTCHD1 in ASD, suggesting that both common and rare variants contribute to the disorder.