International Meeting for Autism Research: ASD and ADHD: Alternate Phenotype or Common Issue Etiopathology

ASD and ADHD: Alternate Phenotype or Common Issue Etiopathology

Thursday, May 20, 2010
Franklin Hall B Level 4 (Philadelphia Marriott Downtown)
1:00 PM
R. Delorme , INSERM U 955, IMRB, Psychiatry Genetics, Créteil, France; department of child and adolescent psychiatry, Hôpital Robert Debré, Paris, France
P. Chaste , INSERM U 955, IMRB, Psychiatry Genetics, Créteil, France; Department of Child and Adolescent Psychiatry, Paris, France
C. Moreau , Child and Adolescent Psychiatry, Robert Debré Hospital, Paris, France
C. Paredes , Department of Psychiatry, A. Chenevier Hospital, Créteil, France, Creteil, France
F. Amsellem , Child and Adolescent Psychiatry, Robert Debré Hospital, PAris, France
M. Leboyer , INSERM U 955, IMRB, Psychiatry Genetics, Créteil, France; Fondation FondaMental, Créteil, France
E. Herbrecht , INSERM U 955, IMRB, Psychiatry Genetics, Créteil, France; Fondation FondaMental, Créteil, France
Background: Although attention-deficit/hyperactivity disorder (ADHD) is frequently comorbid with autism spectrum disorder (ASD), it is unclear whether they have a common genetic etiology.
Objectives: Familial relationships between DSM-IV ADHD and ASD are studied in ASD+ADHD and ASD-only.  
Methods: Direct-interview family study of 170 first degree relatives of ASD (119 parents and 51 siblings) with or without a comorbid ADHD (n=30 and n=32 respectively) collected between 2008 and 2009. Age-corrected prevalence rates of ADHD among relatives are estimated from blinded best-estimate diagnoses using survival Kaplan-Meier.
Results: The prevalence of ADHD in both group were relatively high (20%) when compared to its prevalence in general population. However, we were unable to detect any significant difference in age-corrected prevalence rates of ADHD in the ASD-only group when compared to ADHD-ASD group.  There was a slight trend for relatives in the ASD-only group to have more attentive ADHD subtype.
Conclusions: ASD and ADHD seem to be not alternate phenotypes of a single underlying genetic cause. There is an increased risk of comorbid ADHD and ASD in ASD families, possibly reflecting some overlapping neurobiology or pathophysiology. However, the size of our sample and the absence of a control group limit the pertinence of our results.
See more of: Clinical Phenotype
See more of: Autism Symptoms