Elucidating X chromosome influences on Attention Deficit Hyperactivity Disorder and executive function

Area of Science:

• Neuroscience
• Genetics
• Pediatrics

Background:

• Turner syndrome (TS) is a genetic condition affecting females, characterized by a missing or altered X chromosome.
• Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder impacting behavior and cognition.
• Understanding the interplay between TS and ADHD can shed light on X-linked genetic influences.

Purpose of the Study:

• To define specific behavioral and cognitive profiles of ADHD in girls with TS.
• To compare these profiles to those with idiopathic ADHD and neurotypical controls.
• To investigate potential X-linked genetic contributions to ADHD in TS.

Main Methods:

• A multilevel-model approach was employed.
• 49 girls with TS (aged 5-12) were compared to 37 neurotypical females.
• Behavioral (BASC-2) and neurocognitive (NEPSY) measures were used, with comparisons to ADHD reference data.

Main Results:

• 51% of girls with TS exhibited ADHD-associated behaviors (TS/+ADHD).
• The TS/+ADHD subgroup showed behavioral profiles comparable to boys with ADHD, but higher hyperactivity than girls with ADHD.
• TS girls with ADHD-associated behaviors had lower attention and executive function scores than controls, similar to idiopathic ADHD.

Conclusions:

• ADHD-related issues in TS are prevalent and as severe as in idiopathic ADHD.
• The ADHD phenotype in TS appears distinct from TS-related cognitive features like visuospatial deficits.
• Findings suggest X-linked haploinsufficiency contributes to increased ADHD risk in TS.