Note: This article includes our follow-up suggestions regarding its implications for families including a member diagnosed with Chronic Fatigue Syndrome.
A new study by the New Jersey Chronic Fatigue Syndrome (CFS) Association found that the syndrome occurs in the family members of physician-diagnosed CFS patients much more frequently than in the general population.
This holds true not just for the blood relatives of CFS patients –particularly their offspring – but also for the unrelated spouses and partners sharing their households.
Which means that “both the presence of close household contact and genetic relationship in some families appear to represent risk factors for the development of CFS,” the researchers write.
The questionnaire-based study is reported in the June 2006 issue of the Journal of Chronic Fatigue Syndrome. Key findings are that:
Overall, 45 of the 219 CFS-diagnosed patients whose families were studied (20.5 percent) had one or more “family members” with diagnosed CFS. This includes blood relatives and co-habiting spouses/partners who have been diagnosed by a physician according to CDC criteria.
Unrelated spouses/partners of the CFS patients were eight times more likely than the general population to have CFS. (Six of 186 spouses and partners, or 3.2 percent of them, were diagnosed with CFS, compared with 0.42 percent for the general population, as calculated in a past community-based study by Jason, et al.)
Offspring of the CFS patients were 13 times more likely than the general population to have CFS. (Twelve of the patients’ 235 offspring, or 5.1 percent, had CFS.)
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Parents and siblings of the patients were nearly three times more likely to have CFS. (Eight of 730, or 1.1 percent.) The greater incidence in offspring suggests that “close household contact may have more influence than genetics in accounting for the occurrence of CFS in the offspring.”
None of the patients’ 131 step- and adoptive relatives had CFS.
Sixty-nine percent of the CFS patients (151 of 219) were also diagnosed with Fibromyalgia, though the report does not sort out its likely incidence among family members. Similarly, 37 percent of the patients (81 of 219) were diagnosed with multiple chemical sensitivities.
The authors speculate that the actual numbers of affected family members may be significantly larger. Other studies have indicated that patients may be unaware of more distant relatives’ symptoms – and that “a large proportion of CFS sufferers lack a diagnosis.” Therefore the questionnaire used for the study also asked about symptoms of CFS among relatives not diagnosed by a doctor.
Based on these findings, the authors estimate that the total number of family members with undiagnosed chronic fatigue outnumbered the diagnosed groups by more than two to one for both offspring and spouses/partners, and by as much as 10 to one for parents and siblings.
To review further findings of this detail-rich study, titled “Prevalence of Chronic Fatigue Syndrome and Chronic Fatigue within Families of CFS Patients,” by Rosemary A. Underhill and Ruth O’Gorman, go to http://www.haworthpress.com/store/product.asp?sku=J092 
What this means for you:
1. Families in which one member is diagnosed with Chronic Fatigue Syndrome should be alert to the significant possibility that blood relatives, but particularly offspring and spouses/partners in the patient’s household, may be at risk for CFS.
2. Many symptoms of CFS, such as fatigue, sleep problems, and depression, can be masked or mimicked by normal teenage behaviors and lifestyles. Knowing that CFS may be transmitted – or that susceptibility to it may be genetic – can lead to earlier identification, diagnosis, and treatment to improve outcomes and quality of life for the family.