Circulating MicroRNA Let-7d in Attention-Deficit/Hyperactivity Disorder

Area of Science:

• Biochemistry
• Genetics
• Pediatrics

Background:

• Attention-deficit/hyperactivity disorder (ADHD) lacks established molecular diagnostic signatures in clinical practice.
• MicroRNAs (miRNAs) are emerging as potential biomarkers for various neurological and psychiatric conditions.

Purpose of the Study:

• To investigate the clinical significance of circulating serum miRNA let-7d as a potential molecular signature for ADHD.
• To explore the association between serum miRNA let-7d levels and ADHD diagnosis and clinical outcomes.

Main Methods:

• A case-control study involving 35 newly diagnosed ADHD subjects and age/gender-matched controls.
• Serum samples were analyzed for miRNA let-7d and galectin-3 levels using quantitative methods.
• A 1-year follow-up was conducted to assess clinical improvement in relation to miRNA levels.

Main Results:

• Circulating serum miRNA let-7d levels were significantly higher in ADHD subjects compared to controls (p < 0.05).
• Elevated miRNA let-7d was strongly associated with ADHD diagnosis (odds ratio 16.7, p < 0.05).
• Serum galectin-3 was down-regulated in ADHD, with 66% of ADHD subjects showing low expression (p < 0.05).
• Subjects with lower circulating miRNA let-7d exhibited a significantly higher rate of clinical improvement over 1 year (p < 0.05).

Conclusions:

• Circulating miRNA let-7d is elevated in the serum of children with ADHD.
• MiRNA let-7d shows potential as a novel, non-invasive molecular biomarker for ADHD diagnosis.
• Serum galectin-3 levels may also play a role in ADHD pathophysiology and warrant further investigation.