Bryan has just been diagnosed with attention deficit hyperactivity disorder (ADHD) . His sister Sarah has never been diagnosed with ADHD. Which of the following genes might differ between Bryan and Sarah?

A) DRD4
B) SSRI
C) 5-HTT
D) APOA

ADHD

Attention Deficit Hyperactivity Disorder, a neurological condition characterized by problems with focus, impulsiveness, and excessive activity.

DRD4

A gene associated with the dopamine receptor D4, involved in the neurotransmission system and linked to behaviors such as novelty seeking.

SSRI

Selective Serotonin Reuptake Inhibitors, a class of medications commonly used to treat depression and anxiety disorders by increasing the levels of serotonin in the brain.