Atrial fibrillation is the most common heart rhythm disorder and thus, having some relatives with the same arrhythmia is not uncommon. As you get older it is more likely your atrial fibrillation is related to comorbidities rather than a genetic condition. Everybody has a higher risk for developing atrial fibrillation with increasing age.
However it is observed that in some families the risk of atrial fibrillation is higher, even at a young age or without any other medical conditions. This is called familial atrial fibrillation. In some rare cases it is shown that changes in some genes can be responsible, but in most cases the cause is still unclear. More research is needed to clarify the genetic factors associated with familial atrial fibrillation.
If you have relatives with atrial fibrillation and are worried you may develop the condition, you should discuss this with your doctor. Your doctor can identify risk factors for atrial fibrillation and can help you treat them.