New ADHD findings

A combination of rare and common genetic variations could play a part in biological pathways linked to Attention Deficit Hyperactivity Disorder (ADHD). Cardiff University scientists revealed last year that children with the condition, like those with autism, were more likely than unaffected individuals to carry duplicated or omitted small DNA segments known as copy number variants (CNVs). The findings suggested that rare genetic variations contribute to ADHD risk. Similar findings have been found for autism, schizophrenia and intellectual disability. Now a wider study by the same team and colleagues in Eire and Scotland has replicated the initial findings that these large, rare CNVs are more common in children with ADHD than amongst the general population. Their findings additionally suggest a more common type of genetic variant called Single-Nucleotide Polymorphisms (SNPs) may also be relevant to ADHD risk. It has been difficult to identify specific common genetic variants for disorders like ADHD and autism.