RESUMO
Heterotrimeric G proteins are immediate transducers of G protein-coupled receptors-the biggest receptor family in metazoans-and play innumerate functions in health and disease. A set of de novo point mutations in GNAO1 and GNAI1, the genes encoding the α-subunits (Gαo and Gαi1, respectively) of the heterotrimeric G proteins, have been described to cause pediatric encephalopathies represented by epileptic seizures, movement disorders, developmental delay, intellectual disability, and signs of neurodegeneration. Among such mutations, the Gln52Pro substitutions have been previously identified in GNAO1 and GNAI1. Here, we describe the case of an infant with another mutation in the same site, Gln52Arg. The patient manifested epileptic and movement disorders and a developmental delay, at the onset of 1.5 weeks after birth. We have analyzed biochemical and cellular properties of the three types of dominant pathogenic mutants in the Gln52 position described so far: Gαo[Gln52Pro], Gαi1[Gln52Pro], and the novel Gαo[Gln52Arg]. At the biochemical level, the three mutant proteins are deficient in binding and hydrolyzing GTP, which is the fundamental function of the healthy G proteins. At the cellular level, the mutants are defective in the interaction with partner proteins recognizing either the GDP-loaded or the GTP-loaded forms of Gαo. Further, of the two intracellular sites of Gαo localization, plasma membrane and Golgi, the former is strongly reduced for the mutant proteins. We conclude that the point mutations at Gln52 inactivate the Gαo and Gαi1 proteins leading to aberrant intracellular localization and partner protein interactions. These features likely lie at the core of the molecular etiology of pediatric encephalopathies associated with the codon 52 mutations in GNAO1/GNAI1.
Assuntos
Encefalopatias/genética , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Glutamina/genética , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Membrana Celular/metabolismo , Pré-Escolar , Eletroencefalografia , Complexo de Golgi/metabolismo , Guanosina Trifosfato/metabolismo , Humanos , Hidrólise , Lactente , Imageamento por Ressonância Magnética , Masculino , Proteínas Mutantes/metabolismo , Ligação Proteica , Relação Estrutura-Atividade , Frações Subcelulares/metabolismoRESUMO
Approximately 30% of individuals with autism spectrum disorder (ASD) experience developmental regression, the etiology of which remains largely unknown. We performed a complete literature search and identified 47 genes that had been implicated in such cases. We sequenced these genes in a preselected cohort of 134 individuals with regressive autism. In total, 16 variants in 12 genes with evidence supportive of pathogenicity were identified. They were classified as variants of uncertain significance based on ACMG standards and guidelines. Among these were recurring variants in GRIN2A and PLXNB2, variants in genes that were linked to syndromic forms of ASD (GRIN2A, MECP2, CDKL5, SCN1A,PCDH19, UBE3A, and SLC9A6), and variants in the form of oligogenic heterozygosity (EHMT1, SLC9A6, and MFSD8).
Assuntos
Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/patologia , Regulação da Expressão Gênica , Marcadores Genéticos , Predisposição Genética para Doença , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mutação , Criança , Pré-Escolar , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Lactente , MasculinoRESUMO
Non-nutritive sucking behaviors such as finger- and tongue-sucking, tongue thrust, lips- or cheek-sucking, nail-, lip- or tongue-biting and other pressure habits represent risk factors for malocclusion. The association between psycho-neurological disorders and different types of malocclusion in children with sucking habits was long studied. During neurological examination, many children with sucking habits are diagnosed as Minimal Cerebral Dysfunction or Attention Deficit Hyperactivity Disorder (ADHD) bearers. The aim of this study is to assess the psycho-neurological status and motor disorders in children with malocclusion and normal occlusion. 135 children, aged between 8 and 12 years old, were examined, 42 children with normal occlusion and 93 children with different types of malocclusion. Besides clinical examination, all children were studied by the following psychoneurological methods: 1) Parent's Questionnaire, 2) Diagnostic interview Kiddie-Sads 3) Physical and Neurological Exam for Subtle Signs and 4) stabilometric tests. This study shows as in presence of dentofacial anomalies, pressure habits, ADHD reports significant effects on the functional state of the motor system: increases are noted in all basic parameters of statokinesiograms (crossed distance, sway area and ellipse surface), which lead to increased physiologic energy costs to maintain the vertical position of the body.
Assuntos
Comportamento Infantil , Hábitos , Má Oclusão/psicologia , Comportamento de Sucção/fisiologia , Ansiedade/psicologia , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Estudos de Casos e Controles , Criança , Linguagem Infantil , Oclusão Dentária , Feminino , Sucção de Dedo/psicologia , Marcha/fisiologia , Humanos , Hipercinese/fisiopatologia , Hipercinese/psicologia , Masculino , Má Oclusão/fisiopatologia , Destreza Motora/fisiologia , Hábito de Roer Unhas/psicologia , Exame Neurológico , Exame Físico , Postura/fisiologia , Hábitos Linguais/psicologiaRESUMO
The objective of the study was to compare the efficacy and tolerability of once-daily atomoxetine (< or =1.8 mg/(kg day) with those of placebo in children and adolescents (aged 6-16 years) with attention-deficit/hyperactivity disorder [ADHD (DSM-IV)]. This randomized, placebo-controlled, double-blind trial was conducted in Russia. The primary efficacy measure was baseline-to-end point changes in Attention-Deficit/Hyperactivity Disorder Rating Scale-IV-Parent Version: Investigator-Administered and Scored (ADHDRS-IV-Parent:Inv) total score. Tolerability measures included treatment-emergent signs and symptoms (TESS), laboratory values and weight. Compared with patients in the placebo group (n = 33), patients treated with atomoxetine (n = 72) with a mean final dose of 1.4 mg/kg showed significantly greater improvement in ADHDRS-IV-Parent:Inv total score (least-squares mean: atomoxetine, -15.8; placebo, -11.4; p = 0.013). The most common TESS in the atomoxetine group included anorexia [atomoxetine, n = 13 (18.1%); placebo, n = 2 (6.1%)], somnolence, n = 11 versus n = 3 (15.3% vs. 9.1%, respectively), abdominal pain n = 9 versus n = 1 (12.5% vs. 3.0%, respectively) and nausea, n = 8 versus n = 1 (11.1% vs. 3.0%, respectively). Seven patients in the atomoxetine group and two in the placebo group experienced clinically important weight loss during the study (> or =7% from baseline; mean change, kg: atomoxetine, -0.6; placebo, 0.1; p = 0.032). Atomoxetine is efficacious in improving ADHD symptoms in children and adolescents. Atomoxetine treatment may be associated with a numerically higher incidence of anorexia, somnolence, abdominal pain and nausea, as well as statistically greater losses in body weight.