Publications by authors named "J G Halldorsson"
Article Synopsis
- Several copy number variants have been linked to neuropsychiatric disorders and cognitive abilities, with a focus on the 15q11.2(BP1-BP2) deletion that is tied to learning disabilities and brain structure changes.
- This study expands the sample size to explore how the 15q11.2 deletion impacts dyslexia and dyscalculia, revealing it heightens the risk of these conditions and is associated with a smaller left fusiform gyrus.
- Through neuropsychological testing and brain imaging techniques, the research shows that this deletion significantly alters cognitive and neurological processes related to both dyslexia and dyscalculia.
Only a few common variants in the sequence of the genome have been shown to impact cognitive traits. Here we demonstrate that polygenic scores of educational attainment predict specific aspects of childhood cognition, as measured with IQ. Recently, three sequence variants were shown to associate with educational attainment, a confluence phenotype of genetic and environmental factors contributing to academic success.
View Article and Find Full Text PDFIn a small fraction of patients with schizophrenia or autism, alleles of copy-number variants (CNVs) in their genomes are probably the strongest factors contributing to the pathogenesis of the disease. These CNVs may provide an entry point for investigations into the mechanisms of brain function and dysfunction alike. They are not fully penetrant and offer an opportunity to study their effects separate from that of manifest disease.
View Article and Find Full Text PDFPrimary Objectives: To assess long-term effects of early traumatic brain injury (TBI) on mental health, cognition, behaviour and adjustment and to identify prognostic factors.
Methods And Procedures: A 1-year nationwide cohort of all 0-19 year old Icelandic children and adolescents diagnosed with TBI in 1992-1993 (n = 550) received a questionnaire with clinical outcome scales and questions on TBI and socio-economic status (SES) by mail ∼16 years post-injury. A control group (n = 1232), newly selected from the National Registry, received the same questionnaire.