Expanding the phenotype of Kleefstra syndrome: speech, language and cognition in 103 individuals.

OBJECTIVES: Speech and language impairments are core features of the neurodevelopmental genetic condition Kleefstra syndrome. Communication has not been systematically examined to guide intervention recommendations. We define the speech, language and cognitive phenotypic spectrum in a large cohort of individuals with Kleefstra syndrome. METHOD: 103 individuals with Kleefstra syndrome (40 males, median age 9.5 years, range 1-43 years) with pathogenic variants (52 9q34.3 deletions, 50 intragenic variants, 1 balanced translocation) were included. Speech, language and non-verbal communication were assessed. Cognitive, health and neurodevelopmental data were obtained. RESULTS: The cognitive spectrum ranged from average intelligence (12/79, 15%) to severe intellectual disability (12/79, 15%). Language ability also ranged from average intelligence (10/90, 11%) to severe intellectual disability (53/90, 59%). Speech disorders occurred in 48/49 (98%) verbal individuals and even occurred alongside average language and cognition. Developmental regression occurred in 11/80 (14%) individuals across motor, language and psychosocial domains. Communication aids, such as sign and speech-generating devices, were crucial for 61/103 (59%) individuals including those who were minimally verbal, had a speech disorder or following regression. CONCLUSIONS: The speech, language and cognitive profile of Kleefstra syndrome is broad, ranging from severe impairment to average ability. Genotype and age do not explain the phenotypic variability. Early access to communication aids may improve communication and quality of life.

Mendelian randomization: causal inference leveraging genetic data.

Mendelian randomization (MR) leverages genetic information to examine the causal relationship between phenotypes allowing for the presence of unmeasured confounders. MR has been widely applied to unresolved questions in epidemiology, making use of summary statistics from genome-wide association studies on an increasing number of human traits. However, an understanding of essential concepts is necessary for the appropriate application and interpretation of MR. This review aims to provide a non-technical overview of MR and demonstrate its relevance to psychiatric research. We begin with the origins of MR and the reasons for its recent expansion, followed by an overview of its statistical methodology. We then describe the limitations of MR, and how these are being addressed by recent methodological advances. We showcase the practical use of MR in psychiatry through three illustrative examples - the connection between cannabis use and psychosis, the link between intelligence and schizophrenia, and the search for modifiable risk factors for depression. The review concludes with a discussion of the prospects of MR, focusing on the integration of multi-omics data and its extension to delineating complex causal networks.

Are Genetic and Environmental Risk Factors for Psychopathology Amplified in Children with Below-Average Intelligence? A Population-Based Twin Study.

There is a negative association between intelligence and psychopathology. We analyzed data on intelligence and psychopathology to assess this association in seven-year-old Dutch twin pairs (ranging from 616 to 14,150 depending on the phenotype) and estimated the degree to which genetic and environmental factors common to intelligence and psychopathology explain the association. Secondly, we examined whether genetic and environmental effects on psychopathology are moderated by intelligence. We found that intelligence, as assessed by psychometric IQ tests, correlated negatively with childhood psychopathology, as assessed by the DSM-oriented scales of the Child Behavior Check List (CBCL). The correlations ranged between - .09 and - .15 and were mainly explained by common genetic factors. Intelligence moderated genetic and environmental effects on anxiety and negative affect, but not those on ADHD, ODD, and autism. The heritability of anxiety and negative affect was greatest in individuals with below-average intelligence. We discuss mechanisms through which this effect could arise, and we end with some recommendations for future research.

Evolutionary Trends of Polygenic Scores in European Populations From the Paleolithic to Modern Times.

This study examines the temporal and geographical evolution of polygenic scores (PGSs) across cognitive measures (Educational Attainment [EA], Intelligence Quotient [IQ]), Socioeconomic Status (SES), and psychiatric conditions (Autism Spectrum Disorder [ASD], schizophrenia [SCZ]) in various populations. Our findings indicate positive directional selection for EA, IQ, and SES traits over the past 12,000 years. Schizophrenia and autism, while similar, showed different temporal patterns, aligning with theories suggesting they are psychological opposites. We observed a decline in PGS for neuroticism and depression, likely due to their genetic correlations and pleiotropic effects on intelligence. Significant PGS shifts from the Upper Paleolithic to the Neolithic periods suggest lifestyle and cognitive demand changes, particularly during the Neolithic Revolution. The study supports a mild hypothesis of Gregory Clark's model, showing a noticeable rise in genetic propensities for intelligence, academic achievement and professional status across Europe from the Middle Ages to the present. While latitude strongly influenced height, its impact on schizophrenia and autism was smaller and varied. Contrary to the cold winters theory, the study found no significant correlation between latitude and intelligence.

Gene-environment pathways to cognitive intelligence and psychotic-like experiences in children.

In children, psychotic-like experiences (PLEs) are related to risk of psychosis, schizophrenia, and other mental disorders. Maladaptive cognitive functioning, influenced by genetic and environmental factors, is hypothesized to mediate the relationship between these factors and childhood PLEs. Using large-scale longitudinal data, we tested the relationships of genetic and environmental factors (such as familial and neighborhood environment) with cognitive intelligence and their relationships with current and future PLEs in children. We leveraged large-scale multimodal data of 6,602 children from the Adolescent Brain and Cognitive Development Study. Linear mixed model and a novel structural equation modeling (SEM) method that allows estimation of both components and factors were used to estimate the joint effects of cognitive phenotypes polygenic scores (PGSs), familial and neighborhood socioeconomic status (SES), and supportive environment on NIH Toolbox cognitive intelligence and PLEs. We adjusted for ethnicity (genetically defined), schizophrenia PGS, and additionally unobserved confounders (using computational confound modeling). Our findings indicate that lower cognitive intelligence and higher PLEs are significantly associated with lower PGSs for cognitive phenotypes, lower familial SES, lower neighborhood SES, and less supportive environments. Specifically, cognitive intelligence mediates the effects of these factors on PLEs, with supportive parenting and positive school environments showing the strongest impact on reducing PLEs. This study underscores the influence of genetic and environmental factors on PLEs through their effects on cognitive intelligence. Our findings have policy implications in that improving school and family environments and promoting local economic development may enhance cognitive and mental health in children.

Childhood is a critical period for brain development. Difficult experiences during this developmental phase may contribute to reduced intelligence and poorer mental health later in life. Genetics and environmental factors also play roles. For example, having family support or a higher family income has been linked to better brain health outcomes for children. Delusions or hallucinations, or other psychotic-like experiences during childhood, are linked with poor mental health later in life. Children who experience psychotic-like episodes between the ages of nine and eleven have a higher risk of developing schizophrenia or related conditions. Environmental circumstances during childhood also appear to play a crucial role in shaping the risk of schizophrenia or related conditions. Park, Lee et al. show that positive parenting and supportive school and neighborhood environments boost child intelligence and mental health. In the experiments, Park, Lee et al. analyzed data on 6,602 children to determine how genetics and environmental factors shaped their intelligence and mental health. The models show that children with higher intelligence have a lower risk of psychosis. Both genetics and supportive environments contribute to higher intelligence. Complex interactions between biology and social factors shape children's intelligence and mental health. Beneficial genetics and coming from a family with more financial resources are helpful. Yet, social environments, such as having parents who use positive child-rearing practices, or having supportive schools or neighborhoods, have protective effects that can offset other disadvantages. Policies that help parents, encourage supportive school environments, and strengthen neighborhoods may boost children's intelligence and mental health later in life.

Evaluation of genomic factors and early childhood stimulation on intelligence in children from a Brazilian birth cohort: The primary role of independent factors.

BACKGROUND: Childhood cognitive abilities are a predictor of health outcomes and adult income potential. Identifying factors associated with childhood intelligence and their interactions is essential in behavioral research. We assessed the impact of genetic variants and early child stimulation (ECS) on child intelligence and examined their possible interaction as potential modifiers of IQ in a population-based longitudinal study. METHODS: Participants of the 2004 Pelotas Birth Cohort study (N = 4231) underwent intelligent quotient (IQ) by WISC-III assessment at 6 years of age. At 24 and 48-months, mothers answered five ECS marker questions, whose sum was used to create a score. The polygenic score for intelligence (IQ-PGS) was constructed from the GWAS-weighted estimate of cognition. Association was assessed using multiple linear regression models adjusted for maternal, family, and child confounding variables. To explore the possible influence of skin color and ethnoracial classification, the regression models were stratified according to the skin color variable, as a sensitivity analysis. RESULTS: In the adjusted analysis, IQ-PGS (ß = 0.79, 95% confidence interval [95% CI] 0.26;1.31) as well as ECS (ß = 2.34; 95% CI: 1.76;2.92) were associated with IQ in this sample. The association between IQ-PGS and IQ was significant only in the white Brazilian group in the sensitivity analysis. However, there was no interaction between IQ-PGS and ECS on IQ (p(IQ-PGS x ECS) = 0.46). CONCLUSIONS: ECS did not modify the impact of genetic potential on intellectual development during childhood, suggesting that genetic factors and ECS exert independent effects on the IQ levels of children.

Irritability in young people with copy number variants associated with neurodevelopmental disorders (ND-CNVs).

A range of rare mutations involving micro-deletion or -duplication of genetic material (copy number variants (CNVs)) have been associated with high neurodevelopmental and psychiatric risk (ND-CNVs). Irritability is frequently observed in childhood neurodevelopmental conditions, yet its aetiology is largely unknown. Genetic variation may play a role, but there is a sparsity of studies investigating the presentation of irritability in young people with ND-CNVs. This study aimed to investigate whether there is a difference in irritability in young people with rare ND-CNVs compared to those without ND-CNVs, and to what extent irritability is associated with psychiatric diagnoses and cognitive ability (IQ). Irritability and broader psychopathology were assessed in 485 young people with ND-CNVs and 164 sibling controls, using the child and adolescent psychiatric assessment. Autism was assessed using the social communication questionnaire, and intelligence quotient (IQ) by the Wechsler abbreviated scale of intelligence. Fifty four percent of young people with ND-CNVs met the threshold for irritability; significantly more than controls (OR = 3.77, CI = 3.07-7.90, p = 5.31 × 10-11). When controlling for the presence of other psychiatric comorbidities, ND-CNV status was still associated with irritability. There was no evidence for a relationship between irritability and IQ. Irritability is an important aspect of the clinical picture in young people with ND-CNVs. This work shows that genetic variation is associated with irritability in young people with ND-CNVs, independent of psychiatric comorbidities or IQ impairment. Clinicians should be aware of this increased risk to inform management and interventions.

Associations of childhood, adolescence, and midlife cognitive function with DNA methylation age acceleration in midlife.

Prior studies showed increased age acceleration (AgeAccel) is associated with worse cognitive function among old adults. We examine the associations of childhood, adolescence and midlife cognition with AgeAccel based on DNA methylation (DNAm) in midlife. Data are from 359 participants who had cognition measured in childhood and adolescence in the Child Health and Development study, and had cognition, blood based DNAm measured during midlife in the Disparities study. Childhood cognition was measured by Raven's Progressive Matrices and Peabody Picture Vocabulary Test (PPVT). Adolescent cognition was measured only by PPVT. Midlife cognition included Wechsler Test of Adult Reading (WTAR), Verbal Fluency (VF), Digit Symbol (DS). AgeAccel measures including Horvath, Hannum, PhenoAge, GrimAge and DunedinPACE were calculated from DNAm. Linear regressions adjusted for potential confounders were utilized to examine the association between each cognitive measure in relation to each AgeAccel. There are no significant associations between childhood cognition and midlife AgeAccel. A 1-unit increase in adolescent PPVT, which measures crystalized intelligence, is associated with 0.048-year decrease of aging measured by GrimAge and this association is attenuated after adjustment for adult socioeconomic status. Midlife crystalized intelligence measure WTAR is negatively associated with PhenoAge and DunedinPACE, and midlife fluid intelligence measure (DS) is negatively associated with GrimAge, PhenoAge and DunedinPACE. AgeAccel is not associated with VF in midlife. In conclusion, our study showed the potential role of cognitive functions at younger ages in the process of biological aging. We also showed a potential relationship of both crystalized and fluid intelligence with aging acceleration.

Studying the relationship between intelligence quotient and schizophrenia polygenic scores in a family design with first-episode psychosis population.

BACKGROUND: The intelligence quotient (IQ) of patients with first-episode psychosis (FEP) and their unaffected relatives may be related to the genetic burden of schizophrenia (SCZ). The polygenic score approach can be useful for testing this question. AIM: To assess the contribution of the polygenic risk scores for SCZ (PGS-SCZ) and polygenic scores for IQ (PGS-IQ) to the individual IQ and its difference from the mean IQ of the family (named family-IQ) through a family-based design in an FEP sample. METHODS: The PAFIP-FAMILIES sample (Spain) consists of 122 FEP patients, 131 parents, 94 siblings, and 176 controls. They all completed the WAIS Vocabulary subtest for IQ estimation and provided a DNA sample. We calculated PGS-SCZ and PGS-IQ using the continuous shrinkage method. To account for relatedness in our sample, we performed linear mixed models. We controlled for covariates potentially related to IQ, including age, years of education, sex, and ancestry principal components. RESULTS: FEP patients significantly deviated from their family-IQ. FEP patients had higher PGS-SCZ than other groups, whereas the relatives had intermediate scores between patients and controls. PGS-IQ did not differ between groups. PGS-SCZ significantly predicted the deviation from family-IQ, whereas PGS-IQ significantly predicted individual IQ. CONCLUSIONS: PGS-SCZ discriminated between different levels of genetic risk for the disorder and was specifically related to patients' lower IQ in relation to family-IQ. The genetic background of the disorder may affect neurocognition through complex pathological processes interacting with environmental factors that prevent the individual from reaching their familial cognitive potential.

FMR1 Protein Expression Correlates with Intelligence Quotient in Both Peripheral Blood Mononuclear Cells and Fibroblasts from Individuals with an FMR1 Mutation.

Fragile X syndrome (FXS) is the most common heritable form of intellectual disability and is caused by CGG repeat expansions exceeding 200 (full mutation). Such expansions lead to hypermethylation and transcriptional silencing of the fragile X messenger ribonucleoprotein 1 (FMR1) gene. As a consequence, little or no FMR1 protein (FMRP) is produced; absence of the protein, which normally is responsible for neuronal development and maintenance, causes the syndrome. Previous studies have demonstrated the causal relationship between FMRP levels and cognitive abilities in peripheral blood mononuclear cells (PBMCs) and dermal fibroblast cell lines of patients with FXS. However, it is arguable whether PBMCs or fibroblasts would be the preferred surrogate for measuring molecular markers, particularly FMRP, to represent the cognitive impairment, a core symptom of FXS. To address this concern, CGG repeats, methylation status, FMR1 mRNA, and FMRP levels were measured in both PBMCs and fibroblasts derived from 66 individuals. The findings indicated a strong association between FMR1 mRNA expression levels and CGG repeat numbers in PBMCs of premutation males after correcting for methylation status. Moreover, FMRP expression levels from both PBMCs and fibroblasts of male participants with a hypermethylated full mutation and with mosaicism demonstrated significant association between the intelligence quotient levels and FMRP levels, suggesting that PBMCs may be preferable for FXS clinical studies, because of their greater accessibility.

Thyroid function variations within the reference range and cognitive function: A two-sample Mendelian randomization study.

BACKGROUND: The causal relationship between thyroid function variations within the reference range and cognitive function remains unknown. We aimed to explore this causal relationship using a Mendelian randomization (MR) approach. METHODS: Summary statistics of a thyroid function genome-wide association study (GWAS) were obtained from the ThyroidOmics consortium, including reference range thyroid stimulating hormone (TSH) (N = 54,288) and reference range free thyroxine (FT4) (N = 49,269). GWAS summary statistics on cognitive function were obtained from the Social Science Genetic Association Consortium (SSGAC) and the UK Biobank, including cognitive performance (N = 257,841), prospective memory (N = 152,605), reaction time (N = 459,523), and fluid intelligence (N = 149,051). The primary method used was inverse-variance weighted (IVW), supplemented with weighted median, Mr-Egger regression, and MR-Pleiotropy Residual Sum and Outlier. Several sensitivity analyses were conducted to identify heterogeneity and pleiotropy. RESULTS: An increase in genetically associated TSH within the reference range was suggestively associated with a decline in cognitive performance (ß = -0.019; 95%CI: -0.034 to -0.003; P = 0.017) and significantly associated with longer reaction time (ß = 0.016; 95 % CI: 0.005 to 0.027; P = 0.004). Genetically associated FT4 levels within the reference range had a significant negative relationship with reaction time (ß = -0.030; 95%CI:-0.044 to -0.015; P = 4.85 × 10-5). These findings remained robust in the sensitivity analyses. CONCLUSIONS: Low thyroid function within the reference range may have a negative effect on cognitive function, but further research is needed to fully understand the nature of this relationship. LIMITATIONS: This study only used GWAS data from individuals of European descent, so the findings may not apply to other ethnic groups.

Inteligencia intrapersonal y desarrollo en las personas con síndrome de Down / No disponible

La inteligencia intrapersonal, una de las siete inteligencias formuladas por Howard Gardner, tiene que ver con conocerse a sí mismo; reconocer y gestionar el mundo de las emociones y los sentimientos; y gestionar y orientar la propia conducta. Las personas con discapacidad intelectual disponen de inteligencia intrapersonal en niveles muy diversos; y son capaces de desplegar esta inteligencia en contextos variados. En cualquier caso, la inteligencia intrapersonal es susceptible de ejercitarse desde edades tempranas, mejorando por tanto de manera gradual las competencias personales vinculadas a dicha inteligencia. Para establecer la relación entre los tres componentes de la inteligencia intrapersonal (autoconocimiento, autogestión de emociones y autocontrol de la conducta) y el desarrollo personal nos hemos apoyado en tres metáforas: el desarrollo personal como construcción, como ascensión y como viaje. Se muestran experiencias y programas que contribuyen a mejorar las competencias relacionadas con la inteligencia intrapersonal

Intrapersonal intelligence, one of the seven intelligences formulated by Howard Gardner, has to do with knowing yourself; recognizing and coping with emotions and feelings; and managing own behavior. People with intellectual disabilities have intrapersonal intelligence on many different levels; and they are able to deploy this intelligence in different contexts. Intrapersonal intelligence is able to exercise since early age, thereby improving gradually personal skills linked to that intelligence. To establish the relationship between the three components of intrapersonal intelligence (self-awareness, self-management of emotions and self-control of behavior) and personal development, we have relied on three metaphors: personal development such as construction, as ascension and as a journey. Experiences and programs that improve the skills related to intrapersonal intelligence are described

Inteligencia humana: un acercamiento teórico desde dimensiones filosóficas y psicológicas / Human intelligence: a theoretical approach from philosophical and psychological dimensions

Se ofrecen algunas concepciones y criterios que orienten y estimulen a los estudiantes y profesionales a pensar en la temática de la inteligencia humana, necesariamente polémica y que requiere la discusión y la investigación colectivas. Por ello no se propone decir la última palabra, sino promover el pensamiento y la discusión en torno a esta temática que tan importante para todos los seres humanos en general y en particular para los profesionales de la Psicología, Defectología entre otros. Para la realización de este trabajo se tienen en cuenta los criterios de varios autores en el empleo del método cualitativo de la teoría fundamentada que se encarga de describir teorías, conceptos, hipótesis y proposiciones con vista a desarrollar una perspectiva teórica en un solo estudio, en este caso sobre determinantes psicológicos de la automedicación en el adulto mayor por medio de la revisión bibliográfica según los métodos del nivel teórico de investigación: análisis-síntesis, inducción-educción, modelación y enfoque sistémico que permitieron hacer las valoraciones pertinentes y tener en cuenta los enfoques de otros investigadores(AU)

Some concepts and criteria are offered to guide and encourage students and professionals to consider the issue of human intelligence, necessarily controversial and require collective discussion and research. Therefore we propose not the last word, but to promote thought and discussion on this subject which is so important for all human beings in general and in particular for professionals in psychology, Defectology among others. To carry out this work we had on the criteria of several authors in the use of qualitative method of grounded theory that handles describe the theories, concepts, hypotheses and propositions with a view to developing a theoretical perspective in a single study, our case on psychological determinants of self-medication in the elderly through the literature review by the methods of theoretical research: analysis-synthesis, induction, deduction, modeling and systemic approach that allowed us to make appropriate assessments and consider the approach of other researchers(AU)

Psicobiología de las altas capacidades intelectuales. Una revisión actualizada / Psychobiology of giftedness. An updated review

Las personas con altas capacidades intelectuales están dotadas de un sistema cognitivo más eficiente, capaz de lograr objetivos con menos recursos. El desarrollo adecuado de este potencial es un determinante importante para la salud y el bienestar social y personal. El objetivo de este trabajo es recopilar y sintetizar los últimos hallazgos sobre los mecanismos neurobiológicos subyacentes. Los estudios de asociaciones genéticas han identificado genes y loci genéticos que generan propiedades celulares asociadas con la inteligencia. La aparición de la transcriptómica y la neurociencia celular proporcionan datos sobre el desarrollo diferencial de las células cerebrales asociadas con la alta capacidad. Los estudios de imágenes cerebrales aportan una visión macroscópica, estructural y funcional, de las áreas involucradas en la manifestación de la inteligencia. Los modelos neurocomputacionales del desarrollo cognitivo intentan explicar las trayectorias del desarrollo en función de la poligenicidad y las variaciones en el nivel de estimulación ambiental

Gifted people are endowed with a more efficient cognitive system, and capable of achieving objectives with fewer resources. The proper development of this potential is an important determinant for health and social and personal well-being. The aim of this work is to collect and analyse the latest findings on the underlying neurobiological mechanisms. Studies of genetic associations have identified genes and genetic loci that generate cellular properties associated with intelligence. The appearance of transcriptomics and cellular neuroscience provide data on the differential development of brain cells associated with giftedness. Brain imaging studies provide us with a macroscopic, structural, and functional vision of the areas involved in intelligence. The neuro-computational models of cognitive development try to explain the trajectories of development in terms of polygenicity and variations in the level of environmental stimulation

El autismo en personas con síndrome de Down / No disponible

No disponible

O sujeito na epistemologia genética / The subject in genetic epistemology

Sugere-se neste ensaio que, na epistemologia genética, o sujeito se dirige ao mundo, se interessa por ele e é um princípio de auto-organização. Ontologicamente, seu modo de existência é o do encontro: encontro com o mundo. Epistemologicamente, seu modo de conhecimento é o da presença: presença do mundo. O construtivismo, a tese de que o conhecimento é construção de relações, começa como presença, o que exclui a noção de conhecimento como representação. Destaca-se a centralidade da noção de auto-organização na elucidação do conceito de sujeito, bem como um limite dessa noção, quando se trata de transformar o mundo. Na conclusão, são feitas algumas sugestões para superá-lo(AU)

Algunas ideas sobre la verdad, el amor, la voluntad y la ética del libro del desasosiego de Bernardo Soares, de Fernando Pessoa / Some ideas on the truth, the love, the will and the ethics of the book of the uneasiness or Bernardine Soares, Fernando Pessoa

Fernando Pessoa (1888-1935) es uno de los escritores más famosos del siglo XX, en lengua portuguesa, ampliamente leído en varios idiomas y cada vez más estudiado. A través de su legado literario, con ocasión del análisis de algunos de sus textos, redactados con reconocida maestría y estética, se intenta entrever algo de su realidad más íntima en lo referente a temas relacionados con la verdad, el amor, la voluntad y la ética. Se recogen algunas ideas de un hombre cuya vida parece marcada por la tristeza de no hallar un sentido para existir, que a su vez sea referencia para desplegar todas las dimensiones de su ser

La esquisencefalia: malformación cerebral infrecuente / Schizencephaly: a rare congenital brain malformation

Introducción: La esquisencefalia (ESQ) es un raro trastorno de la migración neuronal que se caracteriza por la presencia de hendiduras que, atravesando el hemisferio cerebral, se extienden desde los ventrículos laterales hasta la superficie cortical. Caso clínico: Mujer de 11 años con discapacidad intelectual y crisis convulsivas parciales que progresan hacia un síndrome de Lennox-Gastaut de difícil control. La resonancia magnética (RM) cerebral muestra una ESQ parietooccipital bilateral de labio abierto en el lado derecho. Discusión: Clínicamente, la ESQ se caracteriza por diversas discapacidades del desarrollo, entre las que destacan la hemiparesia y las crisis convulsivas. La RM es la modalidad de imagen de elección para el diagnóstico de ESQ. La gravedad del trastorno motor se ve muy influenciada en función de la extensión, la apertura labial, la bilateralidad y el tamaño de la malformación (AU)

Introduction: Schizencephaly is a rare congenital brain anomaly characterized by gray matter-lined clefts in the cerebral mantle, extending from the pial surface to the lateral ventricles, which are lined by heterotopic gray matter. Case report: We report the case of an 11-year-old girl with mental retardation and partial seizures who developed Lennox-Gastaut syndrome. Magnetic resonance imaging (MRI) showed bilateral parietal and occipital schizencephaly (right open-lip schizencephaly).Discussion: Schizencephaly can present with a broad range of developmental disabilities and neurological symptoms, the most frequent of which are seizures and hemiparesis. MRI is the modality of choice for the diagnosis of schizencephaly. The severity of the symptoms usually correlates with the extent of brain involvement (AU)

Intelligence and genetic markers in Chilean children

Genetic markers and total intelligence quotient (IQ) assessed by WISC (Wechsler Intelligence Scale for Children) were studied in children of both sexes from Santiago, Chile. Heterozygous boys for phosphoglucomutase 1 (PGM) and heterozygous girls for haptoglobin (Hp) had lower IQ than homozygoytes. For ABO system, B girls had lower and B boys had higher IQ than children with other ABO phenotypes. These differences were highly significant with the two tailed t'-test (Student's t-test with the Welch-Satterthwaite correction for degrees of freedom), and most of them remained significant after the correction for multiple comparisons. Girls had greater variance of IQ than boys. Relationships between homozygotes and heterozygotes were found in two independent studies. Thus, the genetic relationship found here seems likely to be a true biotic effect.