[Hereditary factors in attention deficit hyperactivity disorder].

Area of Science:

• Neuroscience
• Genetics
• Psychiatry

Context:

• Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder.
• Its pathophysiology is linked to neurotransmitter disturbances, particularly dopamine and noradrenaline.
• Genetic factors significantly contribute to ADHD heritability, with approximately 80% of phenotypic variance attributed to hereditary influences.

Purpose:

• To explore the genetic underpinnings and potential endophenotypes of ADHD.
• To investigate the role of neurotransmission and genetic variants in ADHD.
• To identify objective biological markers for ADHD research.

Summary:

• ADHD is characterized by inattention, hyperactivity, and impulsivity, likely involving dopamine and noradrenaline pathways.
• Genetic studies reveal multiple ADHD-associated chromosomal loci, some overlapping with dyslexia and autism.
• Gene-environment interactions and numerous small-effect genetic variants likely predispose individuals to ADHD.
• Phenotypic heterogeneity in ADHD necessitates the identification of endophenotypes to enhance genetic study power.
• Neuro-imaging reveals frontostriatal, temporal, and cerebellar volume abnormalities in children with ADHD.
• Cerebral abnormalities, but not cerebellar, are also observed in unaffected siblings, suggesting potential endophenotypes.

Impact:

• This research aids in understanding the complex genetic architecture of ADHD.
• Identifying endophenotypes can refine diagnostic criteria and improve the efficacy of genetic studies.
• Findings contribute to the development of targeted therapeutic strategies for ADHD.
• Highlights the potential of neuroimaging and neuropsychological features as ADHD endophenotypes.