title: Bipolar disorder risk alleles in children with ADHD.
abstract: Bipolar disorder (BD) and attention deficit/hyperactivity disorder (ADHD) may share common genetic risk factors as indicated by the high co-morbidity of BD and ADHD, their phenotypic overlap especially in pediatric populations, the high heritability of both disorders, and the co-occurrence in families. We therefore examined whether known polygenic BD risk alleles are associated with ADHD. We chose the eight best SNPs of the recent genome-wide association study (GWAS) of BD patients of German ancestry and the nine SNPs from international GWAS meeting a 'genome-wide significance' level of α = 5 × 10(-8). A GWAS was performed in 495 ADHD children and 1,300 population-based controls using HumanHap550v3 and Human660 W-Quadv1 BeadArrays. We found no significant association of childhood ADHD with single BD risk alleles surviving adjustment for multiple testing. Yet, risk alleles for BD and ADHD were directionally consistent at eight of nine loci with the strongest support for three SNPs in or near NCAN, BRE, and LMAN2L. The polygene analysis for the BP risk alleles at all 14 loci indicated a higher probability of being a BD risk allele carrier in the ADHD cases as compared to the controls. At a moderate power to detect association with ADHD, if true effects were close to estimates from GWAS for BD, our results suggest that the possible contribution of BD risk variants to childhood ADHD risk is considerably lower than for BD. Yet, our findings should encourage researchers to search for common genetic risk factors in BD and childhood ADHD in future studies.
authors.affiliation: University Hospital of Child and Adolescent Psychiatry, University of Bern, Bolligenstr. 111, 3000, Bern 60, Switzerland, bschimme@aol.com.
authors.forename: B G
authors.initials: BG
authors.lastname: Schimmelmann
authors.forename: A
authors.initials: A
authors.lastname: Hinney
authors.forename: A
authors.initials: A
authors.lastname: Scherag
authors.forename: C
authors.initials: C
authors.lastname: Pütter
authors.forename: S
authors.initials: S
authors.lastname: Pechlivanis
authors.forename: S
authors.initials: S
authors.lastname: Cichon
authors.forename: K-H
authors.initials: KH
authors.lastname: Jöckel
authors.forename: S
authors.initials: S
authors.lastname: Schreiber
authors.forename: H E
authors.initials: HE
authors.lastname: Wichmann
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authors.lastname: Albayrak
authors.forename: M
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authors.lastname: Dauvermann
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authors.initials: K
authors.lastname: Konrad
authors.forename: C
authors.initials: C
authors.lastname: Wilhelm
authors.forename: B
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authors.lastname: Herpertz-Dahlmann
authors.forename: G
authors.initials: G
authors.lastname: Lehmkuhl
authors.forename: J
authors.initials: J
authors.lastname: Sinzig
authors.forename: T J
authors.initials: TJ
authors.lastname: Renner
authors.forename: M
authors.initials: M
authors.lastname: Romanos
authors.forename: A
authors.initials: A
authors.lastname: Warnke
authors.forename: K P
authors.initials: KP
authors.lastname: Lesch
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authors.lastname: Reif
authors.forename: J
authors.initials: J
authors.lastname: Hebebrand
mesh_terms: D000293:Adolescent; D000483:Alleles; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000235:genetics*; D001714:Bipolar Disorder / Q000150:complications / Q000235:genetics*; D002648:Child; D005260:Female; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D006239:Haplotypes; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide; D044465:White People / Q000235:genetics