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Zinc inhibits Hedgehog autoprocessing: linking zinc deficiency with Hedgehog activation.

July 17, 2015 - 7:50am
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Zinc inhibits Hedgehog autoprocessing: linking zinc deficiency with Hedgehog activation.

J Biol Chem. 2015 May 1;290(18):11591-600

Authors: Xie J, Owen T, Xia K, Singh AV, Tou E, Li L, Arduini B, Li H, Wan LQ, Callahan B, Wang C

Abstract
Zinc is an essential trace element with wide-ranging biological functions, whereas the Hedgehog (Hh) signaling pathway plays crucial roles in both development and disease. Here we show that there is a mechanistic link between zinc and Hh signaling. The upstream activator of Hh signaling, the Hh ligand, originates from Hh autoprocessing, which converts the Hh precursor protein to the Hh ligand. In an in vitro Hh autoprocessing assay we show that zinc inhibits Hh autoprocessing with a Ki of 2 μm. We then demonstrate that zinc inhibits Hh autoprocessing in a cellular environment with experiments in primary rat astrocyte culture. Solution NMR reveals that zinc binds the active site residues of the Hh autoprocessing domain to inhibit autoprocessing, and isothermal titration calorimetry provided the thermodynamics of the binding. In normal physiology, zinc likely acts as a negative regulator of Hh autoprocessing and inhibits the generation of Hh ligand and Hh signaling. In many diseases, zinc deficiency and elevated level of Hh ligand co-exist, including prostate cancer, lung cancer, ovarian cancer, and autism. Our data suggest a causal relationship between zinc deficiency and the overproduction of Hh ligand.

PMID: 25787080 [PubMed - indexed for MEDLINE]

Folinic acid treatment for schizophrenia associated with folate receptor autoantibodies.

July 17, 2015 - 7:50am
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Folinic acid treatment for schizophrenia associated with folate receptor autoantibodies.

Mol Genet Metab. 2014 Dec;113(4):307-14

Authors: Ramaekers VT, Thöny B, Sequeira JM, Ansseau M, Philippe P, Boemer F, Bours V, Quadros EV

Abstract
BACKGROUND: Auto-antibodies against folate receptor alpha (FRα) at the choroid plexus that block N(5)-methyltetrahydrofolate (MTHF) transfer to the brain were identified in catatonic schizophrenia. Acoustic hallucinations disappeared following folinic acid treatment. Folate transport to the CNS prevents homocysteine accumulation and delivers one-carbon units for methyl-transfer reactions and synthesis of purines. The guanosine derivative tetrahydrobiopterin acts as common co-factor for the enzymes producing dopamine, serotonin and nitric oxide.
METHODS: Our study selected patients with schizophrenia unresponsive to conventional treatment. Serum from these patients with normal plasma homocysteine, folate and vitamin B12 was tested for FR autoantibodies of the blocking type on serial samples each week. Spinal fluid was analyzed for MTHF and the metabolites of pterins, dopamine and serotonin. The clinical response to folinic acid treatment was evaluated.
RESULTS: Fifteen of 18 patients (83.3%) had positive serum FR auto-antibodies compared to only 1 in 30 controls (3.3%) (χ(2)=21.6; p<0.0001). FRα antibody titers in patients fluctuated over time varying between negative and high titers, modulating folate flux to the CNS, which explained low CSF folate values in 6 and normal values in 7 patients. The mean±SD for CSF MTHF was diminished compared to previously established controls (t-test: 3.90; p=0.0002). A positive linear correlation existed between CSF MTHF and biopterin levels. CSF dopamine and serotonin metabolites were low or in the lower normal range. Administration of folinic acid (0.3-1mg/kg/day) to 7 participating patients during at least six months resulted in clinical improvement.
CONCLUSION: Assessment of FR auto-antibodies in serum is recommended for schizophrenic patients. Clinical negative or positive symptoms are speculated to be influenced by the level and evolution of FRα antibody titers which determine folate flux to the brain with up- or down-regulation of brain folate intermediates linked to metabolic processes affecting homocysteine levels, synthesis of tetrahydrobiopterin and neurotransmitters. Folinic acid intervention appears to stabilize the disease process.

PMID: 25456743 [PubMed - indexed for MEDLINE]

Extending the phenotypic spectrum of RBFOX1 deletions: Sporadic focal epilepsy.

July 16, 2015 - 6:24am
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Extending the phenotypic spectrum of RBFOX1 deletions: Sporadic focal epilepsy.

Epilepsia. 2015 Jul 15;

Authors: Lal D, Pernhorst K, Klein KM, Reif P, Tozzi R, Toliat MR, Winterer G, Neubauer B, Nürnberg P, Rosenow F, Becker F, Lerche H, Kunz WS, Kurki MI, Hoffmann P, Becker AJ, Perucca E, Zara F, Sander T, Weber YG

Abstract
Partial deletions of the RBFOX1 gene encoding the neuronal splicing regulator have been reported in a range of neurodevelopmental diseases including idiopathic/genetic generalized epilepsy (IGE/GGE), childhood focal epilepsy, and self-limited childhood benign epilepsy with centrotemporal spikes (BECTS, rolandic epilepsy), and autism. The protein regulates alternative splicing of many neuronal transcripts involved in the homeostatic control of neuronal excitability. Herein, we examined whether structural deletions affecting RBFOX1 exons confer susceptibility to common forms of juvenile and adult focal epilepsy syndromes. We screened 807 unrelated patients with sporadic focal epilepsy, and we identified seven hemizygous exonic RBFOX1 deletions in patients with sporadic focal epilepsy (0.9%) in comparison to one deletion found in 1,502 controls. The phenotypes of the patients carrying RBFOX1 deletions comprise magnetic resonance imaging (MRI)-negative epilepsy of unknown etiology with frontal and temporal origin (n = 5) and two patients with temporal lobe epilepsy with hippocampal sclerosis. The epilepsies were largely pharmacoresistant but not associated with intellectual disability. Our study extends the phenotypic spectrum of RBFOX1 deletions as a risk factor for focal epilepsy and suggests that exonic RBFOX1 deletions are involved in the broad spectrum of focal and generalized epilepsies.

PMID: 26174448 [PubMed - as supplied by publisher]

Genetic Testing for Developmental Disabilities, Intellectual Disability, and Autism Spectrum Disorder

July 10, 2015 - 6:45pm

Genetic Testing for Developmental Disabilities, Intellectual Disability, and Autism Spectrum Disorder

Book. 2015 06

Authors: Sun F, Oristaglio J, Levy SE, Hakonarson H, Sullivan N, Fontanarosa J, Schoelles KM

Abstract
BACKGROUND: Genetics research in recent decades has discovered numerous genetic variants that help explain the etiology of developmental disabilities (DDs). Genetic tests (e.g., array comparative genomic hybridization, sequencing) are rapidly diffusing into clinical practice for diagnosing DDs or, more often, for determining their genetic etiology. An urgent need exists for a better understanding of these tests and their clinical utility.
PURPOSE: This Technical Brief collects and summarizes information on genetic tests clinically available in the United States to detect genetic markers that predispose to DDs. It also identifies, but does not systematically review, existing evidence addressing the tests' clinical utility. This Brief primarily focuses on patients with idiopathic or unexplained DDs, particularly intellectual disability, global developmental delay, and autism spectrum disorder. Several better-defined DD syndromes, including Angelman syndrome, fragile X syndrome, Prader-Willi syndrome, Rett syndrome, Rubinstein-Taybi syndrome, Smith-Magenis syndrome, velocardiofacial syndrome, and Williams syndrome are also included. Patient-centered health outcomes (e.g., functional or symptomatic improvement) and intermediate outcomes (e.g., changes in clinical decisions or family reproductive decisions, the tests' diagnostic accuracy and analytic validity) are examined.
METHODS: We sought input from nine Key Informants to identify important clinical, technology, and policy issues from different perspectives. We searched the National Center for Biotechnology Information's Genetic Testing Registry (GTR) to identify genetic tests. A structured search of studies published since 2000 was performed to identify available evidence that addresses genetic tests' clinical utility.
FINDINGS: Our search of the GTR database identified 672 laboratory-developed tests offered by 63 providers in 29 States. We also identified one test cleared by the U.S. Food and Drug Administration. Common genetic testing methods used include array comparative genomic hybridization, microarray, DNA sequencing (the Sanger method or next-generation sequencing), and polymerase chain reaction. We did not identify any studies that directly assessed the impact of genetic testing on health outcomes. Most of the clinical studies identified for indirect assessment of clinical utility are case series reporting on a test's diagnostic yield.


PMID: 26158183

An ontology for Autism Spectrum Disorder (ASD) to infer ASD phenotypes from Autism Diagnostic Interview-Revised data.

July 8, 2015 - 7:33am

An ontology for Autism Spectrum Disorder (ASD) to infer ASD phenotypes from Autism Diagnostic Interview-Revised data.

J Biomed Inform. 2015 Jul 4;

Authors: Mugzach O, Peleg M, Bagley SC, Guter SJ, Cook EH, Altman RB

Abstract
OBJECTIVE: Our goal is to create an ontology that will allow data integration and reasoning with subject data to classify subjects, and based on this classification, to infer new knowledge on Autism Spectrum Disorder (ASD) and related neurodevelopmental disorders (NDD). We take a first step toward this goal by extending an existing autism ontology to allow automatic inference of ASD phenotypes and Diagnostic & Statistical Manual of Mental Disorders (DSM) criteria based on subjects' Autism Diagnostic Interview-Revised (ADI-R) assessment data.
MATERIALS AND METHODS: Knowledge regarding diagnostic instruments, ASD phenotypes and risk factors was added to augment an existing autism ontology via Ontology Web Language class definitions and semantic web rules. We developed a custom Protégé plugin for enumerating combinatorial OWL axioms to support the many-to-many relations of ADI-R items to diagnostic categories in the DSM. We utilized a reasoner to infer whether 2642 subjects, whose data was obtained from the Simons Foundation Autism Research Initiative, meet DSM-IV-TR (DSM-IV) and DSM-5 diagnostic criteria based on their ADI-R data.
RESULTS: We extended the ontology by adding 443 classes and 632 rules that represent phenotypes, along with their synonyms, environmental risk factors, and frequency of comorbidities. Applying the rules on the data set showed that the method produced accurate results: the true positive and true negative rates for inferring autistic disorder diagnosis according to DSM-IV criteria were 1 and 0.065, respectively; the true positive rate for inferring ASD based on DSM-5 criteria was 0.94.
DISCUSSION: The ontology allows automatic inference of subjects' disease phenotypes and diagnosis with high accuracy.
CONCLUSION: The ontology may benefit future studies by serving as a knowledge base for ASD. In addition, by adding knowledge of related NDDs, commonalities and differences in manifestations and risk factors could be automatically inferred, contributing to the understanding of ASD pathophysiology.

PMID: 26151311 [PubMed - as supplied by publisher]

Systems biology and gene networks in neurodevelopmental and neurodegenerative disorders.

July 8, 2015 - 7:33am

Systems biology and gene networks in neurodevelopmental and neurodegenerative disorders.

Nat Rev Genet. 2015 Jul 7;

Authors: Parikshak NN, Gandal MJ, Geschwind DH

Abstract
Genetic and genomic approaches have implicated hundreds of genetic loci in neurodevelopmental disorders and neurodegeneration, but mechanistic understanding continues to lag behind the pace of gene discovery. Understanding the role of specific genetic variants in the brain involves dissecting a functional hierarchy that encompasses molecular pathways, diverse cell types, neural circuits and, ultimately, cognition and behaviour. With a focus on transcriptomics, this Review discusses how high-throughput molecular, integrative and network approaches inform disease biology by placing human genetics in a molecular systems and neurobiological context. We provide a framework for interpreting network biology studies and leveraging big genomics data sets in neurobiology.

PMID: 26149713 [PubMed - as supplied by publisher]

Do large purine repeat sequences play a role in transcriptional regulation of genes associated with neurological disorders?

July 8, 2015 - 7:33am

Do large purine repeat sequences play a role in transcriptional regulation of genes associated with neurological disorders?

Gene. 2015 Jul 3;

Authors: Singh HN, Rajeswari MR

Abstract
Purine repeat sequences present in genome are known to act as hotspots for mutations leading to chromosomal imbalances. It is established that large purine repeats (PRs) form stable DNA triplex structure which can inhibit gene expression. Friedreich's ataxia (FRDA), the autosomal neurodegenerative disorder is the only human disease known so far, where large purine (GAA) repeat in FXN gene is known to inhibit the expression of frataxin protein. We explored the hidden purine repeats (PRn with n≥200) if any, in the human genome to find out their association with neurological disorders. The results showed 28 PRs, which are mostly restricted to the intronic regions. Interestingly, the transcriptome expression analysis of PR-carrying genes (PR-genes) revealed that most of them are down-regulated in neurological disorders (Autism, Alzheimer's disease, schizophrenia, epilepsy, mental retardation, Parkinson's disease, brain tumor) as compared to that in healthy controls. The altered gene expression in brain disorders can be interpreted in terms of a possible expansion of purine repeats leading to formation of very stable DNA-triplex and/or alleviation of the repair enzymes and/or other unknown cellular factors. Interactome analysis identified four PR-genes in signaling pathways whose dysregulation is correlated directly with pathogenesis: GRK5 and KLK6 in Alzheimer's disease; FGF14 in craniosynostosis, mental retardation and FLT1 in neuroferritinopathy. By virtue of being mutational hotspots and their ability to form DNA-triplex, purine repeats in genome disturb the genome integrity and interfere with the transcriptional regulation. However, validation of the disease linkage of PR-genes can be validated using knock-out techniques.

PMID: 26149656 [PubMed - as supplied by publisher]

DNA Methylation Analysis of HTR2A Regulatory Region in Leukocytes of Autistic Subjects.

July 8, 2015 - 7:33am

DNA Methylation Analysis of HTR2A Regulatory Region in Leukocytes of Autistic Subjects.

Autism Res. 2015 Jul 7;

Authors: Hranilovic D, Blazevic S, Stefulj J, Zill P

Abstract
Disturbed brain and peripheral serotonin homeostasis is often found in subjects with autism spectrum disorder (ASD). The role of the serotonin receptor 2A (HTR2A) in the regulation of central and peripheral serotonin homeostasis, as well as its altered expression in autistic subjects, have implicated the HTR2A gene as a major candidate for the serotonin disturbance seen in autism. Several studies, yielding so far inconclusive results, have attempted to associate autism with a functional SNP -1438 G/A (rs6311) in the HTR2A promoter region, while possible contribution of epigenetic mechanisms, such as DNA methylation, to HTR2A dysregulation in autism has not yet been investigated. In this study, we compared the mean DNA methylation within the regulatory region of the HTR2A gene between autistic and control subjects. DNA methylation was analysed in peripheral blood leukocytes using bisulfite conversion and sequencing of the HTR2A region containing rs6311 polymorphism. Autistic subjects of rs6311 AG genotype displayed higher mean methylation levels within the analysed region than the corresponding controls (P < 0.05), while there was no statistically significant difference for AA and GG carriers. Our study provides preliminary evidence for increased HTR2A promoter methylation in leukocytes of a portion of adult autistic subjects, indicating that epigenetic mechanisms might contribute to HTR2A dysregulation observed in individuals with ASD. Autism Res 2015. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

PMID: 26149086 [PubMed - as supplied by publisher]

Autism phenotype versus registered diagnosis in Swedish children: prevalence trends over 10 years in general population samples.

July 8, 2015 - 7:33am
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Autism phenotype versus registered diagnosis in Swedish children: prevalence trends over 10 years in general population samples.

BMJ. 2015;350:h1961

Authors: Lundström S, Reichenberg A, Anckarsäter H, Lichtenstein P, Gillberg C

Abstract
OBJECTIVE: To compare the annual prevalence of the autism symptom phenotype and of registered diagnoses for autism spectrum disorder during a 10 year period in children.
DESIGN: Population based study.
SETTING: Child and Adolescent Twin Study and national patient register, Sweden.
PARTICIPANTS: 19, 993 twins (190 with autism spectrum disorder) and all children (n=1,078,975; 4620 with autism spectrum disorder) born in Sweden over a 10 year period from 1993 to 2002.
MAIN OUTCOME MEASURES: Annual prevalence of the autism symptom phenotype (that is, symptoms on which the diagnostic criteria are based) assessed by a validated parental telephone interview (the Autism-Tics, ADHD and other Comorbidities inventory), and annual prevalence of reported diagnoses of autism spectrum disorder in the national patient register.
RESULTS: The annual prevalence of the autism symptom phenotype was stable during the 10 year period (P=0.87 for linear time trend). In contrast, there was a monotonic significant increase in prevalence of registered diagnoses of autism spectrum disorder in the national patient register (P<0.001 for linear trend).
CONCLUSIONS: The prevalence of the autism symptom phenotype has remained stable in children in Sweden while the official prevalence for registered, clinically diagnosed, autism spectrum disorder has increased substantially. This suggests that administrative changes, affecting the registered prevalence, rather than secular factors affecting the pathogenesis, are important for the increase in reported prevalence of autism spectrum disorder.

PMID: 25922345 [PubMed - indexed for MEDLINE]

Haploinsufficiency of XPO1 and USP34 by a de novo 230 kb deletion in 2p15, in a patient with mild intellectual disability and cranio-facial dysmorphisms.

July 7, 2015 - 9:03am
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Haploinsufficiency of XPO1 and USP34 by a de novo 230 kb deletion in 2p15, in a patient with mild intellectual disability and cranio-facial dysmorphisms.

Eur J Med Genet. 2014 Sep;57(9):513-9

Authors: Fannemel M, Barøy T, Holmgren A, Rødningen OK, Haugsand TM, Hansen B, Frengen E, Misceo D

Abstract
2p15p16.1-deletion syndrome was first described in 2007 based on the clinical presentation of two patients. The syndrome is characterized by intellectual disability, autism spectrum disorders, microcephaly, dysmorphic facial features and a variety of congenital organ defects. The precise genotype-phenotype correlation in 2p15-deletion syndrome is not understood. However, greater insight can be obtained by thorough clinical investigation of patients carrying deletions, especially those of small size. We report a 21-year-old male patient with features overlapping the clinical spectrum of the 2p15p16.1-deletion syndrome, such as intellectual disability, dysmorphic facial features, and congenital defects. He carried a 230 kb de novo deletion (chr2:61500346-61733075 bp, hg19), which affects the genes USP34, SNORA70B and XPO1. While there is a lack of functional data on SNORA70B, the involvement of USP34 and XPO1 in the regulation of fundamental developmental processes is well known. We suggest that haploinsufficiency of one or both of these genes is likely to be responsible for the disease in our patient.

PMID: 24911659 [PubMed - indexed for MEDLINE]

Potential benefits and limits of psychopharmacological therapies in pervasive developmental disorders.

July 7, 2015 - 9:03am
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Potential benefits and limits of psychopharmacological therapies in pervasive developmental disorders.

Curr Clin Pharmacol. 2014;9(4):365-76

Authors: Molteni M, Nobile M, Cattaneo D, Radice S, Clementi E

Abstract
The core symptoms of Autistic Spectrum Disorder (ASD) are impairment in reciprocal social interaction, communication, narrow interests, and stereotyped behaviour. These are frequently severe and persistent, although their severity may change over the course of life. Furthermore, the frequently associated symptoms of self-injury, aggressive behaviour, impulsivity, poor attention, anxiety, depression, and sleep disruption, can become a major source of additional distress and interference in functioning. The causes of autism are not yet known, but there is a general consensus that ASDs are highly heritable. Comprehension of the neurobiological basis for autism-spectrum disorders is still in its initial stages: a large body of research, however, has established ASD signs and symptoms are of neurological origin, and suggest that autism is a distributed neural system disorder, which disproportionately impairs many higher order abilities. Currently available medical treatments, primarily address co-morbid symptoms, rather than core symptoms. Thus, in spite of recent advances in psychopharmacology, the treatment approach still has important limits and shows poor efficacy on global outcomes. A potential pathway for improving clinical outcomes is that of the personalised treatment for autism, by using therapeutic drug monitoring (TDM) - a valuable tool for drugs with narrow therapeutic index - as well as systematic genetic background assessment, foreseen in future applications. However, it is already possible to implement an active surveillance programme to address safety concerns and to optimise therapeutic drug interventions in ASD.

PMID: 24050744 [PubMed - indexed for MEDLINE]

Monogenic and chromosomal causes of isolated speech and language impairment.

July 4, 2015 - 8:26am

Monogenic and chromosomal causes of isolated speech and language impairment.

J Med Genet. 2015 Jul 2;

Authors: Barnett CP, van Bon BW

Abstract
The importance of a precise molecular diagnosis for children with intellectual disability, autism spectrum disorder and epilepsy has become widely accepted and genetic testing is an integral part of the diagnostic evaluation of these children. In contrast, children with an isolated speech or language disorder are not often genetically evaluated, despite recent evidence supporting a role for genetic factors in the aetiology of these disorders. Several chromosomal copy number variants and single gene disorders associated with abnormalities of speech and language have been identified. Individuals without a precise genetic diagnosis will not receive optimal management including interventions such as early testosterone replacement in Klinefelter syndrome, otorhinolaryngological and audiometric evaluation in 22q11.2 deletion syndrome, cardiovascular surveillance in 7q11.23 duplications and early dietary management to prevent obesity in proximal 16p11.2 deletions. This review summarises the clinical features, aetiology and management options of known chromosomal and single gene disorders that are associated with speech and language pathology in the setting of normal or only mildly impaired cognitive function.

PMID: 26139234 [PubMed - as supplied by publisher]

Dietary supplementation of omega-3 fatty acids rescues fragile X phenotypes in Fmr1-Ko mice.

July 4, 2015 - 8:26am
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Dietary supplementation of omega-3 fatty acids rescues fragile X phenotypes in Fmr1-Ko mice.

Psychoneuroendocrinology. 2014 Nov;49:119-29

Authors: Pietropaolo S, Goubran MG, Joffre C, Aubert A, Lemaire-Mayo V, Crusio WE, Layé S

Abstract
Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are known to critically influence brain development and functions. Dietary supplementation with n-3 PUFAs has been suggested as a non-pharmacological therapy for a number of developmental disorders, e.g., autistic spectrum disorders (ASD), but human studies so far have led to conflicting results. Furthermore, it has been hypothesized that the therapeutic impact of n-3 PUFAs on these disorders might be explained by their anti-inflammatory properties and their promoting effects on synaptic function and plasticity, but no clear evidence has been produced in this direction. We evaluated the impact of n-3 PUFA dietary supplementation in a mouse model of fragile X syndrome (FXS), i.e., a major developmental disease and the most frequent monogenic cause of ASD. Fmr1-KO and wild-type mice were provided with a diet enriched or not with n-3 PUFAs from weaning until adulthood when they were tested for multiple FXS-like behaviors. The brain expression of several cytokines and of brain-derived neurotrophic factor (BDNF) was concomitantly assessed as inflammatory and synaptic markers. n-3 PUFA supplementation rescued most of the behavioral abnormalities displayed by Fmr1-KO mice, including alterations in emotionality, social interaction and non-spatial memory, although not their deficits in social recognition and spatial memory. n-3 PUFAs also rescued most of the neuroinflammatory imbalances of KOs, but had a limited impact on their BDNF deficits. These results demonstrate that n-3 PUFAs dietary supplementation, although not a panacea, has a considerable therapeutic value for FXS and potentially for ASD, suggesting a major mediating role of neuroinflammatory mechanisms.

PMID: 25080404 [PubMed - indexed for MEDLINE]

Ultrastructural analyses in the hippocampus CA1 field in Shank3-deficient mice.

July 3, 2015 - 6:59am

Ultrastructural analyses in the hippocampus CA1 field in Shank3-deficient mice.

Mol Autism. 2015;6:41

Authors: Uppal N, Puri R, Yuk F, Janssen WG, Bozdagi-Gunal O, Harony-Nicolas H, Dickstein DL, Buxbaum JD, Hof PR

Abstract
BACKGROUND: The genetics of autism spectrum disorder (hereafter referred to as "autism") are rapidly unfolding, with a significant increase in the identification of genes implicated in the disorder. Many of these genes are part of a complex landscape of genetic variants that are thought to act together to cause the behavioral phenotype associated with autism. One of the few single-locus causes of autism involves a mutation in the SH3 and multiple ankyrin repeat domains 3 (SHANK3) gene. Previous electrophysiological studies in mice with Shank3 mutations demonstrated impairment in synaptic long-term potentiation, suggesting a potential disruption at the synapse.
METHODS: To understand how variants in SHANK3 would lead to such impairments and manifest in the brain of patients with autism, we assessed the presence of synaptic pathology in Shank3-deficient mice at 5 weeks and 3 months of age, focusing on the stratum radiatum of the CA1 field. This study analyzed both Shank3 heterozygous and homozygous mice using an electron microscopy approach to determine whether there is a morphological correlate to the synaptic functional impairment.
RESULTS: As both synaptic strength and plasticity are affected in Shank3-deficient mice, we hypothesized that there would be a reduction in synapse density, postsynaptic density length, and perforated synapse density. No differences were found in most parameters assessed. However, Shank3 heterozygotes had significantly higher numbers of perforated synapses at 5 weeks compared to 3 months of age and significantly higher numbers of perforated synapses compared to 5-week-old wildtype and Shank3 homozygous mice.
CONCLUSIONS: Although this finding represents preliminary evidence for ultrastructural alterations, it suggests that while major structural changes seem to be compensated for in Shank3-deficient mice, more subtle morphological alterations, affecting synaptic structure, may take place in an age-dependent manner.

PMID: 26137200 [PubMed - as supplied by publisher]

DNA typing of HLA-A, -C, -B, AND -DRB1 in the children with autism in the Republic of Macedonia.

July 3, 2015 - 6:59am
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DNA typing of HLA-A, -C, -B, AND -DRB1 in the children with autism in the Republic of Macedonia.

Bratisl Lek Listy. 2015;116(1):14-9

Authors: Trajkovski V, Spiroski M

Abstract
In the present study, we report the first DNA analysis of HLA class I and class II alleles in Macedonian autistic subjects. We have analyzed the HLA-A, -C, -B, DRB1 genotypes of 35 autistic patients, and 98 healthy unrelated Macedonians (control group). HLA DNA typing of class I genes was performed using a Reverse Line Strip method (RLS), and the Sequencing Based Typing method (SBT) was used for typing of class II genes. In the autistic subjects for HLA-A locus 14 alleles have been identified with 2 being predominant *02 (25.7 %), and *24 (18.6 %). Among the 11 identified HLA-C alleles, 3 were predominant such as *12 (20.0 %), *07 (17.1 %), and *03 (12.9 %). Among the 18 identified HLA-B alleles, 2 were predominant: *51 (18.6 %), and *18 (11.4 %). For HLA-DRB1 locus, 10 alleles have been identified with 2 of them predominant such as: *11 (21.4 %), and *01 (14.3 %). The allele and haplotype frequencies in the patients group were compared to those of 98 control subjects. Our results showed significantly increased frequencies of HLA-C*03 (OR = 2.74*; χ2 = 4.68; p = 0.03), and HLA-DRB1*01 (OR = 3.10*; χ2 = 6.26; p = 0.012) alleles in autistic patients when compared to the controls. The most frequent haplotype frequencies in autistic sample were A*11-C*12-B*52-DRB1*15 (2.9 %), A*24-C*03-B*55-DRB1*16 (2.9 %), and A*24-C*03-B*55-DRB1*16 (2.9 %), but they were not statistically significant when compared to the control group. None of our patients carried allele or haplotype, which were protective in our population. Hardy-Weinberg equilibrium in autistic group showed that HLA-A (p < 0.03), HLA-C (p < 0.04), and HLA-DRB1 (p < 0.002) loci were in linkage disequilibria. In the control group, we found only for the HLA-DRB1 locus linkage disequilibrium (p < 0.002). Our results demonstrated the association of HLA-C*03 and HLA-DRB1*01 alleles with Macedonian autistic patients (Tab. 7, Ref. 37).

PMID: 25666956 [PubMed - indexed for MEDLINE]

Complex phenotype with social communication disorder caused by mosaic supernumerary ring chromosome 19p.

July 3, 2015 - 6:59am
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Complex phenotype with social communication disorder caused by mosaic supernumerary ring chromosome 19p.

BMC Med Genet. 2014;15:132

Authors: Demily C, Rossi M, Chesnoy-Servanin G, Martin B, Poisson A, Sanlaville D, Edery P

Abstract
BACKGROUND: Deletions or duplications of chromosome 19 are rare and there is no previous report in the literature of a ring chromosome derived from proximal 19p. Copy Number Variants (CNVs) responsible for complex phenotypes with Social Communication Disorder (SCD), may contribute to improve knowledge about the distinction between intellectual deficiency and autism spectrum disorders.
CASE PRESENTATION: We report the clinical and cytogenetic characterization of a patient (male, 33 years-old, first child of healthy Portuguese non-consanguineous parents) presenting with a complex phenotype including SCD without intellectual deficiency and carrying a mosaic supernumerary ring chromosome 19p. Microarray-Based Comparative Genomic Hybridization and Fluorescence in situ Hybridization were performed. Genetic analysis showed a large mosaic interstitial duplication 19p13.12p12 of the short arm of chromosome 19, spanning 8.35 Mb. Our data suggested a putative association between psychosocial dysfunction and mosaic pure trisomy 19p13.2p12.
CONCLUSION: This clinical report demonstrated the need to analyze more discreet trait-based subsets of complex phenotypes to improve the ability to detect genetic effects. To address this question and the broader issue of deciphering the yet unknown genetic contributors to complex phenotype with SCD, we suggest performing systematic psychological and psychiatric assessments in patients with chromosomal abnormalities.

PMID: 25496186 [PubMed - indexed for MEDLINE]

Molecular and clinical analyses of 16q24.1 duplications involving FOXF1 identify an evolutionarily unstable large minisatellite.

July 3, 2015 - 6:59am
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Molecular and clinical analyses of 16q24.1 duplications involving FOXF1 identify an evolutionarily unstable large minisatellite.

BMC Med Genet. 2014;15:128

Authors: Dharmadhikari AV, Gambin T, Szafranski P, Cao W, Probst FJ, Jin W, Fang P, Gogolewski K, Gambin A, George-Abraham JK, Golla S, Boidein F, Duban-Bedu B, Delobel B, Andrieux J, Becker K, Holinski-Feder E, Cheung SW, Stankiewicz P

Abstract
BACKGROUND: Point mutations or genomic deletions of FOXF1 result in a lethal developmental lung disease Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins. However, the clinical consequences of the constitutively increased dosage of FOXF1 are unknown.
METHODS: Copy-number variations and their parental origin were identified using a combination of array CGH, long-range PCR, DNA sequencing, and microsatellite analyses. Minisatellite sequences across different species were compared using a gready clustering algorithm and genome-wide analysis of the distribution of minisatellite sequences was performed using R statistical software.
RESULTS: We report four unrelated families with 16q24.1 duplications encompassing entire FOXF1. In a 4-year-old boy with speech delay and a café-au-lait macule, we identified an ~15 kb 16q24.1 duplication inherited from the reportedly healthy father, in addition to a de novo ~1.09 Mb mosaic 17q11.2 NF1 deletion. In a 13-year-old patient with autism and mood disorder, we found an ~0.3 Mb duplication harboring FOXF1 and an ~0.5 Mb 16q23.3 duplication, both inherited from the father with bipolar disorder. In a 47-year old patient with pyloric stenosis, mesenterium commune, and aplasia of the appendix, we identified an ~0.4 Mb duplication in 16q24.1 encompassing 16 genes including FOXF1. The patient transmitted the duplication to her daughter, who presented with similar symptoms. In a fourth patient with speech and motor delay, and borderline intellectual disability, we identified an ~1.7 Mb FOXF1 duplication adjacent to a large minisatellite. This duplication has a complex structure and arose de novo on the maternal chromosome, likely as a result of a DNA replication error initiated by the adjacent large tandem repeat. Using bioinformatic and array CGH analyses of the minisatellite, we found a large variation of its size in several different species and individuals, demonstrating both its evolutionarily instability and population polymorphism.
CONCLUSIONS: Our data indicate that constitutional duplication of FOXF1 in humans is not associated with any pediatric lung abnormalities. We propose that patients with gut malrotation, pyloric or duodenal stenosis, and gall bladder agenesis should be tested for FOXF1 alterations. We suggest that instability of minisatellites greater than 1 kb can lead to structural variation due to DNA replication errors.

PMID: 25472632 [PubMed - indexed for MEDLINE]

A rare duplication on chromosome 16p11.2 is identified in patients with psychosis in Alzheimer's disease.

July 3, 2015 - 6:59am
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A rare duplication on chromosome 16p11.2 is identified in patients with psychosis in Alzheimer's disease.

PLoS One. 2014;9(11):e111462

Authors: Zheng X, Demirci FY, Barmada MM, Richardson GA, Lopez OL, Sweet RA, Kamboh MI, Feingold E

Abstract
Epidemiological and genetic studies suggest that schizophrenia and autism may share genetic links. Besides common single nucleotide polymorphisms, recent data suggest that some rare copy number variants (CNVs) are risk factors for both disorders. Because we have previously found that schizophrenia and psychosis in Alzheimer's disease (AD+P) share some genetic risk, we investigated whether CNVs reported in schizophrenia and autism are also linked to AD+P. We searched for CNVs associated with AD+P in 7 recurrent CNV regions that have been previously identified across autism and schizophrenia, using the Illumina HumanOmni1-Quad BeadChip. A chromosome 16p11.2 duplication CNV (chr16: 29,554,843-30,105,652) was identified in 2 of 440 AD+P subjects, but not in 136 AD subjects without psychosis, or in 593 AD subjects with intermediate psychosis status, or in 855 non-AD individuals. The frequency of this duplication CNV in AD+P (0.46%) was similar to that reported previously in schizophrenia (0.46%). This duplication CNV was further validated using the NanoString nCounter CNV Custom CodeSets. The 16p11.2 duplication has been associated with developmental delay, intellectual disability, behavioral problems, autism, schizophrenia (SCZ), and bipolar disorder. These two AD+P patients had no personal of, nor any identified family history of, SCZ, bipolar disorder and autism. To the best of our knowledge, our case report is the first suggestion that 16p11.2 duplication is also linked to AD+P. Although rare, this CNV may have an important role in the development of psychosis.

PMID: 25379732 [PubMed - indexed for MEDLINE]

A girl with West syndrome and autistic features harboring a de novo TBL1XR1 mutation.

July 3, 2015 - 6:59am
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A girl with West syndrome and autistic features harboring a de novo TBL1XR1 mutation.

J Hum Genet. 2014 Oct;59(10):581-3

Authors: Saitsu H, Tohyama J, Walsh T, Kato M, Kobayashi Y, Lee M, Tsurusaki Y, Miyake N, Goto Y, Nishino I, Ohtake A, King MC, Matsumoto N

Abstract
Recently, de novo mutations in TBL1XR1 were found in two patients with autism spectrum disorders. Here, we report on a Japanese girl presenting with West syndrome, Rett syndrome-like and autistic features. Her initial development was normal until she developed a series of spasms at 5 months of age. Electroencephalogram at 7 months showed a pattern of hypsarrhythmia, which led to a diagnosis of West syndrome. Stereotypic hand movements appeared at 8 months of age, and autistic features such as deficits in communication, hyperactivity and excitability were observed later, at 4 years and 9 months. Whole exome sequencing of the patient and her parents revealed a de novo TBL1XR1 mutation [c.209 G>A (p.Gly70Asp)] occurring at an evolutionarily conserved amino acid in an F-box-like domain. Our report expands the clinical spectrum of TBL1XR1 mutations to West syndrome with Rett-like features, together with autistic features.

PMID: 25102098 [PubMed - indexed for MEDLINE]

CNVs in neuropsychiatric disorders.

July 2, 2015 - 8:52am
Related Articles

CNVs in neuropsychiatric disorders.

Hum Mol Genet. 2015 Jun 30;

Authors: Kirov G

Abstract
Over the last few years at least 11 copy number variations (CNVs) have been shown convincingly to increase risk to developing schizophrenia: deletions at 1q21.1, NRXN1, 3q29, 15q11.2, 15q13.3 and 22q11.2, and duplications at 1q21.1, 7q11.23, 15q11.2-q13.1, 16p13.1 and proximal 16p11.2. They are very rare, found cumulatively in 2.4% of patients with schizophrenia and in only 0.5% of controls. They all increase risk for other neurodevelopmental disorders, such as developmental delay and autism spectrum disorders, where they are found at higher rates (3.3%). Their involvement in bipolar affective disorder is much less prominent. All of them affect multiple genes (apart from NRXN1) and cause substantial increases in risk to develop schizophrenia (odds ratios of 2 to over 50). Their penetrance for any neurodevelopmental disorder is high, from ∼10% to nearly 100%. Carriers of these CNVs display cognitive deficits, even when free of neuropsychiatric disorders.

PMID: 26130694 [PubMed - as supplied by publisher]

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