Language and reading impairments are associated with increased prevalence of non-right-handedness
Filippo Abbondanza, Philip S. Dale, Carol A. Wang, Marianna E. Hayiou‐Thomas, Umar Toseeb, Tanner Koomar, Karen Wigg, Yu Feng, Kaitlyn M. Price, Elizabeth N. Kerr, Sharon Guger, Maureen W. Lovett, Lisa J. Strug, Elsje van Bergen, Conor V. Dolan, J. Bruce Tomblin, Kristina Moll, Gerd Schulte‐Körne, Nina Neuhoff, Andreas Warnke, Simon E. Fisher, Cathy L. Barr, Jacob J. Michaelson, Dorret I. Boomsma, Maggie Snowling, Charles Hulme, Andrew Whitehouse, Craig E. Pennell, Dianne F. Newbury, John Stein, Joel B. Talcott, Dorothy Bishop, Silvia Paracchini
Abstract
Abstract Handedness has been studied for association with language-related disorders because of its link with language hemispheric dominance. No clear pattern has emerged, possibly because of small samples, publication bias, and heterogeneous criteria across studies. Non-right-handedness (NRH) frequency was assessed in N = 2503 cases with reading and/or language impairment and N = 4316 sex-matched controls identified from 10 distinct cohorts (age range 6–19 years old; European ethnicity) using a priori set criteria. A meta-analysis (N cases = 1994) showed elevated NRH % in individuals with language/reading impairment compared with controls (OR = 1.21, CI = 1.06–1.39, p = .01). The association between reading/language impairments and NRH could result from shared pathways underlying brain lateralization, handedness, and cognitive functions.