Fibromyalgia isn't passed directly from parents to children the way diseases such as cystic fibrosis and hemophilia are. But family studies have found that the odds of having fibromyalgia are several times higher in the immediate families of people with fibromyalgia than in families in which no one has fibromyalgia. These observations suggest that heredity is a factor in causing fibromyalgia.
In fact, studies of DNA from family members of people with fibromyalgia and chronic pain syndromes have turned up a number of genes that could help explain why these disorders seem to run in families. Each of these genes plays a role in your nervous system's response to things that hurt, such as pressure and heat. Some of the same genes are also associated with depression and anxiety, which may be the reason why certain antidepressant medications help reduce fibromyalgia symptoms.
Researchers are now trying to connect differences in individuals' pain thresholds to particular variants of specific genes. A variant of the gene that determines how efficiently nerve cells recycle the neurotransmitter serotonin has already been correlated with heightened pain sensitivity.