Writing in the Journal of the Federation of American Societies for Experimental Biology under the title “The Complex of TFII-I, PARP1, and SFPQ Proteins Regulates the DYX1C1 Gene Implicated in Neuronal Migration and Dyslexia,” Isabel Tapia-Páez and colleagues revealed that they have discovered a group of proteins that apparently act together to control the transcription of DNA (deoxyribonucleic acid that forms genetic material) code into RNA (ribonucleic acid which controls synthesis of proteins) code. Although the gene DYX1C1 has been implicated in only a small proportion of cases of dyslexia, it is important in general because the finding moves researchers closer to understanding how genes can influence behavior as complex as reading.
Continue reading ‘How genes may affect dyslexia’
Tag Archive for 'genetics'
Although perceptual explanations for reading problems were common in the early discussions of Learning Disabilities, educators now mostly agree that the language factors have far greater influence on reading problems. A recent study by Nicole Halaar and colleagues underscores this idea and, especially importantly, points to the importance of early childhood language development in later reading competence. In fact, although genetic factors play a role in later reading competence, environmental exert substantial influence.
Of course, given the extensive work on them over the past 20 years, educators understand the importance of phonemic awareness and decoding in reading. But these factors do not completely explain the variation in outcomes for children learning to read. The contributions of semantic and syntactic factors must be included to move closer to explaining why children differ in their reading outcomes, especially when the outcome of concern is facility in comprehending what one has read.
Continue reading ‘Preschool language factors affecting reading achievement’
Dr. M. Romanos and colleagues examined the genetic make-up of several families and found that there are common elements that appear to be associated with ADHD. Although these findings point toward a genetic contribution to ADHD, it is important to note the caveat implied by the final sentence of the abstract: So many factors contribute to ADHD, that these results should not be construed as identifying the precise cause of the disorder. In the full article, the authors are circumspect about this: “The identification [in this study] of several novel linkage regions as well as replication of previously reported loci provides further evidence for the highly heterogeneous genetic etiology of ADHD.”
Sphere: Related ContentGenome-wide linkage analysis of ADHD using high-density SNP arrays: Novel loci at 5q13.1 and 14q12
M Romanos, C. Freitag, C. Jacob, D. W Craig, A. Dempfle, T. T. Nguyen, R. Halperin, S. Walitza, T. J Renner, C. Seitz, J. Romanos, H. Palmason, A. Reif, M. Heine, C. Windemuth-Kieselbach, C. Vogler, J. Sigmund, A. Warnke, H. Schäfer, J. Meyer, D. A. Stephan, & K. P. Lesch
Molecular Psychiatry (2008) 13, 522–530; doi:10.1038/mp.2008.12; published online 26 February 2008
Abstract
Previous genome-wide linkage studies applied the affected sib-pair design; one investigated extended pedigrees of a. genetic isolate. Here, results of a. genome-wide high-density linkage scan of attention-deficit/hyperactivity disorder (ADHD) using an array-based genotyping of approx ~50 K. single nucleotide polymorphism (SNPs) markers are presented. We investigated eight extended pedigrees of German origin that were non-related, not part of a. genetic isolate and ascertained on the basis of clinical referral. Two parametric analyses maximizing LOD scores (MOD) and a. non-parametric analysis for both a. broad and a. narrow phenotype approach were conducted. Novel linkage loci across all families were detected at 2q35, 5q13.1, 6q22-23 and 14q12, within individual families at 18q11.2-12.3. Further linkage regions at 7q21.11, 9q22 and 16q24.1 in all families, and at 1q25.1, 1q25.3, 9q31.1-33.1, 9q33, 12p13.33, 15q11.2-13.3 and 16p12.3-12.2 in individual families replicate previous findings. High-resolution linkage mapping points to several novel candidate genes characterized by dense expression in the brain and potential impact on disorder-relevant synaptic transmission. Our study provides further evidence for common gene effects throughout different populations despite the complex multifactorial etiology of ADHD.
Latest Comments
RSS