Panic disorder, a type of anxiety disorder characterized by unexpected and repeated episodes of intense fear, is thought to caused by a combination of genetic and environmental factors. Approximately 6 million people in the United States suffer from panic disorder, although it is more common in women than in men. For some, the fear of having a panic attack can be debilitating, stopping them from holding a job or interfering with social activities.
Scientists at the Centre for Genomic Regulation (CRG) in Spain recently discovered which gene was responsible for this disorder. According to the researchers, the gene NTRK3 works in the brain to process information about fearful situations and store the memories. When this gene doesn’t work properly, you "overestimate the risk in a situation and therefore feel more frightened and store that information in a more lasting and consistent manner." 
According to the study, how you store memories of events can produce panic disorder. An overactive hippocampus creates exaggerated forms of your memories and stores that version, leading you to believe events are more fearful than they really are. This triggers the amygdale in the brain, which creates a physical reaction to the fear - heart palpitations, dizziness, shortness of breath, nausea. When you store the memories tied to the fear, it returns when you are in a similar situation.
One medication, Gabitril (listed as Tiagabine in the study as the Spanish name for the medication), helps to regulate the brain’s fear inhibition system and may reverse the formation of panic memories. The scientists found that this medication can help alleviate some symptoms of panic disorder by adjusting the way you create and store fear memories. Unfortunately, these medications can have side effects that make it difficult for some people to use.
The scientists hope their research will provide valuable information that can be used to create better treatments - both in medication and therapy. By pinpointing the exact process that occurs when faced with a fearful situation, medications can specifically target the areas that become overactive. Therapist may also be able to use this information to work on cognitive therapy during key moments of fearful situations.
"Facts and Statistics," Date Unknown, Staff Writer, Anxiety and Depression Association of America
"Gene Found Responsible for Susceptibility to Panic Disorder," 2013, Nov. 28, Staff Writer, ScienceDaily