Pilot study: potential transcription markers for adult attention-deficit hyperactivity disorder in whole blood

Abstract

Attention-deficit hyperactivity disorder (ADHD) is a common behavioural disorder that affects not only children and adolescents but also adults; however, diagnosis of adult ADHD is difficult because patients seem to have reduced externalized behaviour. ADHD is a multifactorial disorder in which many genes, all with small effects, are thought to cause the disorder in the presence of unfavourable environmental conditions. Therefore, in this pilot study, we explored the expression profile of a list of previously established candidate genes in peripheral blood samples from adult ADHD subjects (n = 108) and compared these results with those of healthy controls (n = 35). We demonstrate that combining the gene expression levels of dopamine transporter (SLC6A3), dopamine D5 receptor, tryptophan hydroxylase-1, and SNAP25 as predictors in a regression model resulted in sensitivity and specificity of over 80 % (ROC: max R 2 = 0.587, AUC = 0.917, P \ 0.001, 95 % CI: 0.900-0.985). In conclusion, the combination of these four genes could represent a potential method for estimating risk and could be of diagnostic value for ADHD. Nevertheless, further investigation in a larger independent population including different subtypes of ADHD (inattentive, hyperactive, or combined type) patients is required to obtain more specific sets of biomarkers for each subtype as well as to differentiate between child, adolescent, and adulthood forms.Edna Grünblatt and Julia Geißler have contributed equally.Electronic supplementary material The online version of this article

Common and specific genes and peripheral biomarkers in children and adults with attention-deficit/hyperactivity disorder

“…SLC6A3, DRD5, TPH1, SNAP25. In a pilot study in aADHD, some authors demonstrated that combining the gene expression levels of these genes as predictors resulted in sensitivity and specificity of over 80% (Grunblatt et al 2012).…”