Genetic evidence in attention-deficit hyperactivity disorder

January 01, 0001

Genetic evidence in attention-deficit hyperactivity disorder

Large, rare chromosomal deletions and duplications known as copy number variants (CNVs) have been implicated in neurodevelopmental disorders similar to attention- deficit hyperactivity disorder (ADHD). The researchers from the UK, Iceland and Norway aimed to establish whether burden of CNVs was increased in ADHD, and to investigate whether identified CNVs were enriched for loci previously identified in autism and schizophrenia. They undertook a genome-wide analysis of CNVs in 410 children with ADHD and 1156 unrelated ethnically matched controls from the 1958 British Birth Cohort. Children of white UK origin, aged 5—17 years, who met diagnostic criteria for ADHD or hyperkinetic disorder, but not schizophrenia and autism, were recruited from community child psychiatry and paediatric outpatient clinics. Data for full analyses were available for 366 children with ADHD and 1047 controls.

57 large, rare CNVs were identified in children with ADHD and 78 in controls, showing a significantly increased rate of CNVs in ADHD (0.156 vs 0.075). This increased rate of CNVs was particularly high in those with intellectual disability (0.424), although there was also a significant excess in cases with no such disability (0.125). An excess of chromosome 16p13.11 duplications was noted in the ADHD group. CNVs identified in the ADHD cohort were significantly enriched for loci previously reported in both autism and schizophrenia.

The researchers concluded: "Our findings provide genetic evidence of an increased rate of large CNVs in individuals with ADHD and suggest that ADHD is not purely a social construct."

Swinging back towards the medical model.

For the full abstract, click here.

The Lancet 376(9750):1401-1408, 23 October 2010
© 2010 Elsevier Ltd
Rare chromosomal deletions and duplications in attention-deficit hyperactivity disorder: a genome-wide analysis. Nigel M Williams, Irina Zaharieva, Andrew Martin et al. Correspondence to Nigel Williams:

Category: A. General/Unspecified. Keywords: chromosomal, deletions, duplications, attention-deficit hyperactivity disorder, genome-wide analysis, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 5 November 2010

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