Quantitative trait locus for reading disability on chromosome 6p is pleiotropic for attention-deficit/hyperactivity disorder
Version of Record online: 7 FEB 2002
Copyright © 2002 Wiley-Liss, Inc.
American Journal of Medical Genetics
Volume 114, Issue 3, pages 260–268, 8 April 2002
How to Cite
Willcutt, E. G., Pennington, B. F., Smith, S. D., Cardon, L. R., Gayán, J., Knopik, V. S., Olson, R. K. and DeFries, J. C. (2002), Quantitative trait locus for reading disability on chromosome 6p is pleiotropic for attention-deficit/hyperactivity disorder. Am. J. Med. Genet., 114: 260–268. doi: 10.1002/ajmg.10205
- Issue online: 23 OCT 2002
- Version of Record online: 7 FEB 2002
- Manuscript Accepted: 24 OCT 2001
- Manuscript Received: 16 MAY 2001
- National Institute of Child Health and Human Development (NICHD). Grant Numbers: HD-11681, HD-27802, HD-04024
- National Institute of Mental Health (NIMH). Grant Number: MH-38820
- NIMH National Research Service Award. Grant Number: MH-12100
- reading disability;
Comorbidity is pervasive among both adult and child psychiatric disorders; however, the etiological mechanisms underlying the majority of comorbidities are unknown. This study used genetic linkage analysis to assess the etiology of comorbidity between reading disability (RD) and attention-deficit hyperactivity disorder (ADHD), two common childhood disorders that frequently co-occur. Sibling pairs (N = 85) were ascertained initially because at least one individual in each pair exhibited a history of reading difficulties. Univariate linkage analyses in sibling pairs selected for ADHD from within this RD-ascertained sample suggested that a quantitative trait locus (QTL) on chromosome 6p is a susceptibility locus for ADHD. Because this QTL is in the same region as a well-replicated QTL for reading disability, subsequent bivariate analyses were conducted to test if this QTL contributed to comorbidity between the two disorders. Analyses of data from sib pairs selected for reading deficits revealed suggestive bivariate linkage for ADHD and three measures of reading difficulty, indicating that comorbidity between RD and ADHD may be due at least in part to pleiotropic effects of a QTL on chromosome 6p. © 2002 Wiley-Liss, Inc.