1
|
Laasonen M, Lahti-Nuuttila P, Leppämäki S, Tani P, Wikgren J, Harno H, Oksanen-Hennah H, Pothos E, Cleeremans A, Dye MWG, Cousineau D, Hokkanen L. Project DyAdd: Non-linguistic Theories of Dyslexia Predict Intelligence. Front Hum Neurosci 2020; 14:316. [PMID: 32922276 PMCID: PMC7456923 DOI: 10.3389/fnhum.2020.00316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 07/16/2020] [Indexed: 11/13/2022] Open
Abstract
Two themes have puzzled the research on developmental and learning disorders for decades. First, some of the risk and protective factors behind developmental challenges are suggested to be shared and some are suggested to be specific for a given condition. Second, language-based learning difficulties like dyslexia are suggested to result from or correlate with non-linguistic aspects of information processing as well. In the current study, we investigated how adults with developmental dyslexia or ADHD as well as healthy controls cluster across various dimensions designed to tap the prominent non-linguistic theories of dyslexia. Participants were 18–55-year-old adults with dyslexia (n = 36), ADHD (n = 22), and controls (n = 35). Non-linguistic theories investigated with experimental designs included temporal processing impairment, abnormal cerebellar functioning, procedural learning difficulties, as well as visual processing and attention deficits. Latent profile analysis (LPA) was used to investigate the emerging groups and patterns of results across these experimental designs. LPA suggested three groups: (1) a large group with average performance in the experimental designs, (2) participants predominantly from the clinical groups but with enhanced conditioning learning, and (3) participants predominantly from the dyslexia group with temporal processing as well as visual processing and attention deficits. Despite the presence of these distinct patterns, participants did not cluster very well based on their original status, nor did the LPA groups differ in their dyslexia or ADHD-related neuropsychological profiles. Remarkably, the LPA groups did differ in their intelligence. These results highlight the continuous and overlapping nature of the observed difficulties and support the multiple deficit model of developmental disorders, which suggests shared risk factors for developmental challenges. It also appears that some of the risk factors suggested by the prominent non-linguistic theories of dyslexia relate to the general level of functioning in tests of intelligence.
Collapse
Affiliation(s)
- Marja Laasonen
- Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland.,Department of Otorhinolaryngology and Phoniatrics - Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Pekka Lahti-Nuuttila
- Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland.,Department of Otorhinolaryngology and Phoniatrics - Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Sami Leppämäki
- Department of Psychiatry, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Pekka Tani
- Department of Psychiatry, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Jan Wikgren
- Department of Psychology, Centre for Interdisciplinary Brain Research, University of Jyväskylä, Jyväskylä, Finland
| | - Hanna Harno
- Clinical Neurosciences, Department of Neurology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Henna Oksanen-Hennah
- Pediatric Neuropsychiatric Unit, Department of Child Psychiatry, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Emmanuel Pothos
- Department of Psychology, City University of London, London, United Kingdom
| | - Axel Cleeremans
- Center for Research in Cognition & Neurosciences, Université libre de Bruxelles, Brussels, Belgium
| | - Matthew W G Dye
- National Technical Institute for the Deaf, Rochester Institute of Technology, Rochester, NY, United States
| | - Denis Cousineau
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Laura Hokkanen
- Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland
| |
Collapse
|
2
|
Price KM, Wigg KG, Feng Y, Blokland K, Wilkinson M, He G, Kerr EN, Carter TC, Guger SL, Lovett MW, Strug LJ, Barr CL. Genome-wide association study of word reading: Overlap with risk genes for neurodevelopmental disorders. GENES BRAIN AND BEHAVIOR 2020; 19:e12648. [PMID: 32108986 DOI: 10.1111/gbb.12648] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 01/28/2020] [Accepted: 02/24/2020] [Indexed: 12/12/2022]
Abstract
Reading disabilities (RD) are the most common neurocognitive disorder, affecting 5% to 17% of children in North America. These children often have comorbid neurodevelopmental/psychiatric disorders, such as attention deficit/hyperactivity disorder (ADHD). The genetics of RD and their overlap with other disorders is incompletely understood. To contribute to this, we performed a genome-wide association study (GWAS) for word reading. Then, using summary statistics from neurodevelopmental/psychiatric disorders, we computed polygenic risk scores (PRS) and used them to predict reading ability in our samples. This enabled us to test the shared aetiology between RD and other disorders. The GWAS consisted of 5.3 million single nucleotide polymorphisms (SNPs) and two samples; a family-based sample recruited for reading difficulties in Toronto (n = 624) and a population-based sample recruited in Philadelphia [Philadelphia Neurodevelopmental Cohort (PNC)] (n = 4430). The Toronto sample SNP-based analysis identified suggestive SNPs (P ~ 5 × 10-7 ) in the ARHGAP23 gene, which is implicated in neuronal migration/axon pathfinding. The PNC gene-based analysis identified significant associations (P < 2.72 × 10-6 ) for LINC00935 and CCNT1, located in the region of the KANSL2/CCNT1/LINC00935/SNORA2B/SNORA34/MIR4701/ADCY6 genes on chromosome 12q, with near significant SNP-based analysis. PRS identified significant overlap between word reading and intelligence (R2 = 0.18, P = 7.25 × 10-181 ), word reading and educational attainment (R2 = 0.07, P = 4.91 × 10-48 ) and word reading and ADHD (R2 = 0.02, P = 8.70 × 10-6 ; threshold for significance = 7.14 × 10-3 ). Overlap was also found between RD and autism spectrum disorder (ASD) as top-ranked genes were previously implicated in autism by rare and copy number variant analyses. These findings support shared risk between word reading, cognitive measures, educational outcomes and neurodevelopmental disorders, including ASD.
Collapse
Affiliation(s)
- Kaitlyn M Price
- Genetics and Development Division, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Karen G Wigg
- Genetics and Development Division, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Yu Feng
- Genetics and Development Division, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Kirsten Blokland
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Margaret Wilkinson
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Gengming He
- Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Elizabeth N Kerr
- Department of Psychology, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Tasha-Cate Carter
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.,Holland Bloorview Rehabilitation Hospital, Toronto, Ontario, Canada
| | - Sharon L Guger
- Department of Psychology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Maureen W Lovett
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Lisa J Strug
- Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Cathy L Barr
- Genetics and Development Division, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|