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Biomedical subjects

Elena L Grigorenko

Publications and source records attributed to Elena L Grigorenko.

15 recordsLinked to original sources
PubMed2007

Hyperlexia in children with autism spectrum disorders.

We compared the reading-related skills of children with Autism Spectrum Disorders who have hyperlexia (ASD + HPL) with age-matched children with ASD without HPL (ASD - HPL) and with single-word reading-matched typically developing children (TYP). Children with ASD + HPL performed (1) better than did children with ASD - HPL on tasks of single-word reading and pseudoword decoding and (2) equivalently well compared to word-reading-matched TYP children on all reading-related tasks except reading comprehension. It appears that the general underlying model of single-word reading is the same in principle for "typical" and hyperlexic reading. Yet, the study revealed some dissimilarities between these two types of reading when more fine-grained cognitive and linguistic abilities were considered; these dissimilarities warrant further investigations.

Adolescent↗
PubMed2006

Long-term impact of malaria chemoprophylaxis on cognitive abilities and educational attainment: follow-up of a controlled trial.

OBJECTIVES: We investigated the long-term impact of early childhood malaria prophylaxis on cognitive and educational outcomes. DESIGN: This was a household-based cluster-controlled intervention trial. SETTING: The study was conducted in 15 villages situated between 32 km to the east and 22 km to the west of the town of Farafenni, the Gambia, on the north bank of the River Gambia. PARTICIPANTS: A total of 1,190 children aged 3-59 mo took part in the trial. We traced 579 trial participants (291 in the prophylaxis group and 288 in the placebo group) in 2001, when their median age was 17 y 1 mo (range 14 y 9 mo to 19 y 6 mo). INTERVENTIONS: Participants received malaria chemoprophylaxis (dapsone/pyrimethamine) or placebo for between one and three malaria transmission seasons from 1985 to 1987 during the controlled trial. At the end of the trial, prophylaxis was provided for all children under 5 y of age living in the study villages. OUTCOME MEASURES: The outcome measures were cognitive abilities, school enrolment, and educational attainment (highest grade reached at school). RESULTS: There was no significant overall intervention effect on cognitive abilities, but there was a significant interaction between intervention group and the duration of post-trial prophylaxis (p = 0.034), with cognitive ability somewhat higher in the intervention group among children who received no post-trial prophylaxis (treatment effect = 0.2 standard deviations [SD], 95% confidence interval [CI] -0.03 to 0.5) and among children who received less than 1 y of post-trial prophylaxis (treatment effect = 0.4 SD, 95% CI 0.1 to 0.8). The intervention group had higher educational attainment by 0.52 grades (95% CI = -0.041 to 1.089; p = 0.069). School enrolment was similar in the two groups. CONCLUSIONS: The results are suggestive of a long-term effect of malaria prophylaxis on cognitive function and educational attainment, but confirmatory studies are needed.

Journal Article↗
PubMed2006

Learning disabilities in juvenile offenders.

The article briefly reviews the literature on the association between learning disabilities and conduct problems across correctional communities and clinical settings. It first reviews the literature on the prevalence of learning deficiencies among criminal offenders. It then discusses a number of relevant points from studies of the association between low academic achievement and conduct problems in nonincarcerated population samples. Third, it discusses studies of postrelease academic profiles of juvenile offenders. The article closes with a comment on possible future directions of the research linking reduced levels of academic achievement and delinquency.

Adolescent↗
PubMed2005

Developing a SNP panel for forensic identification of individuals.

Single nucleotide polymorphisms (SNPs) are likely in the near future to have a fundamental role in forensics in both human identification and description. However, considerable research is necessary to establish adequate scientific foundations for these applications. In the case of identification, because allele frequencies can vary greatly among populations, the population genetics of match probabilities is a critical issue. Some SNPs, however, show little allele frequency variation among populations while remaining highly informative. We describe here both an efficient strategy for identifying and characterizing such SNPs, and test that strategy on a broad representation of world populations. Markers with high heterozygosity and little frequency variation among African American, European American, and East Asian populations are selected for additional screening on seven populations that provide a sampling of genetic variation from the world's major geographical regions. Those with little allele frequency variation on the seven populations are then screened on a total of 40 populations ( approximately 2100 individuals) and the most promising retained. The preliminary panel of 19 SNPs, from an initial selection of 195 SNPs, gives an average match probability of <10(-7) in most of 40 populations studied and no greater than 10(-6) in the most isolated, inbred populations. Expansion of this panel to approximately 50 comparable SNPs should give match probabilities of about 10(-15) with a small global range.

DNA Fingerprinting↗
PubMed2005

Intelligence, race, and genetics.

In this article, the authors argue that the overwhelming portion of the literature on intelligence, race, and genetics is based on folk taxonomies rather than scientific analysis. They suggest that because theorists of intelligence disagree as to what it is, any consideration of its relationships to other constructs must be tentative at best. They further argue that race is a social construction with no scientific definition. Thus, studies of the relationship between race and other constructs may serve social ends but cannot serve scientific ends. No gene has yet been conclusively linked to intelligence, so attempts to provide a compelling genetic link of race to intelligence are not feasible at this time. The authors also show that heritability, a behavior-genetic concept, is inadequate in regard to providing such a link.

Genetics, Population↗
PubMed2005

Platelet MAO-B, personality, and psychopathology.

The article investigates the relationships between platelet monoamine oxidase-B (MAO-B) activity, personality, and psychopathology (Diagnostic and Statistical Manual of Mental Disorders [4th ed.; American Psychiatric Association, 1994] diagnoses. These relationships were assessed in 178 incarcerated male juvenile delinquents. Even after controlling for smoking, the authors found that both Internalizing and Externalizing Psychopathology were negatively related to MAO-B activity. In the final reduced model, novelty seeking fully mediated the relationships between MAO-B and Externalizing Psychopathology but not between MAO-B and Internalizing Psychopathology. It was hypothesized that low platelet MAO-B activity does not directly predispose individuals to psychopathology but is related to specific personality traits, which in turn represent a vulnerability factor for psychopathology. Future studies should help clarify the nature of the relationships between personality, biological markers, and psychopathology.

Adolescent↗
PubMed2005

The inherent complexities of gene-environment interactions.

The article outlines the complexities of gene-environment interactions in the determination of human disease, especially as they relate to aging, and stresses the importance of continuing such studies, in spite of their inherent difficulties. First, a capsule review of the literature pertaining to studies of gene-environment interactions is presented, and designs and methodologies used to detect these interactions are briefly discussed. Second, research questions and problems that can be addressed as outcomes of gene-environment interaction studies are exemplified. Third, a number of illustrative examples of gene-environment interactions are presented. Fourth, various types of gene-environment interactions are briefly discussed. Fifth, concluding remarks are offered, and possibilities of studying gene-environment interaction within social and biological research on aging are outlined.

Aging↗
PubMed2004

Intelligence and culture: how culture shapes what intelligence means, and the implications for a science of well-being.

This paper discusses the relationship between culture and intelligence. The main message of the paper is that intelligence cannot fully or even meaningfully be understood outside its cultural context. Behaviour that is considered intelligent in one culture may be considered unintelligent in another culture, and vice versa. Moreover, people in different cultures have different implicit (folk) theories of intelligence, so may not even mean the same thing by the word. The relationships between different aspects of intelligence can vary across cultures, with correlations that are positive in one setting proving to be negative in another. The paper opens with a general discussion of issues regarding the relationship between the two concepts. It then describes the theory of successful intelligence, which motivates our work on the interface between culture and intelligence. Finally, the article draws some conclusions.

Cognition↗
PubMed2004

Alleles of a reelin CGG repeat do not convey liability to autism in a sample from the CPEA network.

A recent study by Persico et al. [2001: Mol Psychiatry 6:150-159] suggests alleles of a CGG polymorphism, just 5' of the reelin gene (RELN) initiator codon, confer liability for autism, especially alleles bearing 11 or more CGG repeats (long alleles). The association is consistent across both a case-control and family-based sample. We attempted to replicate their finding using a larger, independent family-based sample from the NIH Collaborative Programs of Excellence in Autism (CPEA) Network. In our data, allele transmissions to individuals with autism versus unaffected individuals are unbiased, both when alleles are classified by repeat length and when they are classified into long/short categories. Because of the apparent linkage of autism to chromosome 7q, particularly related to the development of language, we also evaluate the relationship between Reelin alleles and the age at which autism subjects use their first word or first phrase. Neither is significantly associated with Reelin alleles. Our results are not consistent with a major role for Reelin alleles in liability to autism.

Alleles↗
PubMed2003

Continuing the search for dyslexia genes on 6p.

This study is a continuation and extension of the work with Orton Developmental Dyslexia (DD) pedigrees [Grigorenko et al., 1997; 2000, Grigorenko et al., 2001]. This study utilized an extended sample (N = 176) and a well-saturated map of chromosome 6p (30 markers). Six phenotypes were constructed to span a range of dyslexia-related cognitive processes. These phenotypes were: (1) Phonemic Awareness (of spoken words); (2) Phonological Decoding (of printed nonwords); (3) Rapid Automatized Naming (of colored squares or object drawings); (4) Single Word Reading (orally, of printed real words); (5) Phonemic Awareness/Decoding/Single-Word Reading pathway; and (6) Phonemic Awareness/Rapid Naming/Single-Word Reading pathway. The study resulted in two major findings. First, considering the distributions of the genetic linkage indicators across all phenotypes examined, there appear to be three regions of interest (around markers D6S109, D6S1261, and in the D6S105-D6S265 region). Any of these regions could serve as a starting point in the search for specific gene candidates contributing to the manifestation of DD, yet they all might be echo peaks of a single peak, the boundary of which is difficult to establish due to the limited power of this sample. Second, the DD-related linkage in 6p21.3 appears to be most closely related to the manifestations of DD through phonemic awareness and single-word reading deficits.

Adolescent↗
PubMed2003

Annotation: Hyperlexia: disability or superability?

BACKGROUND: Hyperlexia is the phenomenon of spontaneous and precocious mastery of single-word reading that has been of interest to clinicians and researchers since the beginning of the last century. METHODS: An extensive search of publications on the subject of hyperlexia was undertaken and all available publications were reviewed. RESULTS: The literature can be subdivided into discussions of the following issues: (1) whether hyperlexia is a phenomenon that is characteristic only of specific clinical populations (e.g., children with developmental delays) or whether it can also be observed in the general population; (2) whether hyperlexia is a distinct syndrome comorbid with a number of different disorders or whether it is a part of the spectrum of some other clinical condition(s); (3) whether hyperlexia should be defined through single-word reading superiority with regard to reading comprehension, vocabulary, general intelligence, any combination of the three, or all three characteristics; (4) whether there is a specific neuropsychological profile associated with hyperlexia; (5) whether hyperlexia is characterized by a particular developmental profile; and (6) whether hyperlexia should be viewed as a disability (deficit) or superability (talent). CONCLUSIONS: We interpret the literature as supporting the view that hyperlexia is a superability demonstrated by a very specific group of individuals with developmental disorders (defined through unexpected single-word reading in the context of otherwise suppressed intellectual functioning) rather than as a disability exhibited by a portion of the general population (defined through a discrepancy between levels of single-word reading and comprehension). We simultaneously argue, however, that multifaceted and multi-methodological approaches to studying the phenomenon of hyperlexia, defined within the research framework of understanding single-word reading, are warranted and encouraged.

Adolescent↗
PubMed2002

No evidence for linkage of liability to autism to HOXA1 in a sample from the CPEA network.

A recent study by Ingram et al. [2000b: Teratology 62:393-405] suggests a (His)73(Arg) polymorphism (A:G) in HOXA1 contributes substantially to a liability for autism. Using 68 individuals diagnosed with Autism Spectrum Disorders, they found a significant dearth of G homozygotes and biased transmission of G alleles from parents to affected offspring, especially from mothers. Because the connection between HOXA1 and liability to autism is compelling, we attempted to replicate their finding using a larger, independent sample from the Collaborative Programs of Excellence in Autism (CPEA) network. In our data, genotype frequencies conform to Hardy-Weinberg equilibrium; allele transmissions meet Mendelian expectations; and there is no obvious sex-biased allele transmission. Based on our sample size, calculations suggest that we would have at least 95% power to detect linkage and association even if the A:G polymorphism were to account for only 1% of the heritability of autism. Therefore, although we cannot exclude the possibility that the samples in the two studies are intrinsically different, our data from our sample argue against a major role for HOXA1 (His)73(Arg) in liability to autism.

Asperger Syndrome↗
PubMed2002

A descriptive study of hyperlexia in a clinically referred sample of children with developmental delays.

In this study, we evaluated the incidence of hyperlexia in a clinically referred sample of 80 children with developmental delays. Based on hypotheses previously formulated in the literature, the study investigated the frequency of hyperlexia among boys and girls, the incidence of hyperlexia in children with Pervasive Developmental Disorders (PDD)-spectrum compared with non-PDD diagnoses, the range of IQ and of various cognitive skills in children with and without hyperlexia, and the developmental outcomes of children with and without hyperlexia. The results revealed no significant differences in the frequency of hyperlexia in girls compared with boys. However, the frequency of hyperlexia was significantly elevated among children with PDD compared with children with non-PDD diagnoses. The range of IQ and other cognitive skills and the developmental outcomes of children with hyperlexia were comparable to those of children without hyperlexia.

Child↗