Fibromyalgia is a genetic disease which is inherited. An entire family can be affected by the disease. I am treating a mother, her two girls and her young son. When the two parents have the disease, all the children are affected (there is a pediatric form of fibromyalgia). Doctor Paul St. Amand has treated members of a family which spanned three generations including a two-year-old girl. A few of my patients developed the disease only in their seventies, one at the age of 80.
This age spread would be impossible to explain with only one defective gene. Therefore it seams there is a multigenetic cause of FMS. The number of affected genes, and the spectrum from milder genes (recessive) to more harmful (dominant) ones, permit all types of combinations that determine at what stage in life FMS is expressed and the severity of the symptoms. In those who have only minor defects in the amino acid sequences of the genes responsible, FMS may never fully manifest, or transitorily, or episodically. The genetic disposition explains that an individual may be the first one in his family to have it expressed, his ascendants being, if so, healthy carriers.
Since 85% of fibromyalgia patients are women, it is axiomatic that at least one gene in on the X chromosome.