Key points:
- Research suggests that a family history of chronic illness may represent a predisposing risk factor for ME/CFS – including history of ME/CFS, cancer, autoimmune conditions, and metabolic disorders.
- Little is known about whether those with ME/CFS who have a family history of the disease experience different symptoms to those with ME/CFS but without a family history.
- A study by Professor Leonard Jason, and his colleague, Sarah Ngonmedje, investigated whether symptoms of ME/CFS differ between those with, and without, a family history of the disease.
- Participants included 400 people with ME/CFS (72 with a family history of ME/CFS), and 414 non-ME/CFS chronic illness controls 16 of whom had a family history of ME/CFS).
- Results showed that those with ME/CFS were significantly more likely to have a family history of ME/CFS compared with non-ME/CFS controls.
- Amongst participants with ME/CFS, those with a family history of the disease were more likely to experience gastrointestinal symptoms – including irritable bowel problems, and abdomenal/stomach pain, compared to those without a family history of ME/CFS.
- More research is needed to further explore how family history of chronic illnesses – including ME/CFS, relates to symptoms of the disease.
Background
Research suggests that compared to people without ME/CFS, those with the disease are more likely to have a family member with ME/CFS, or other chronic illnesses including cancer, autoimmune conditions, and metabolic disorders.
For example:
| Author | Summary of findings |
| Albright and colleagues (2011) | Relatives of people with “CFS” were more likely to have “CFS”, with first degree relatives being highest risk compared with other relatives. |
| Endicott (1999) | Mothers of those with “CFS” died younger (average 59.5 years) compared to two control groups (average age of death 66.8 in group 1 who the authors stated had “relatively good physical health” , and 71.0 in group 2 whose physical health was not considered in the study) This study also found that the rate of cancer amongst the mothers of those with “CFS” was higher (average 53%) compared to the control groups (average 33.1% in group 1 and 31% in group 2). |
| Njoku, Jason and colleagues (2008) | Compared with non-blood relatives (i.e. spouse, step-parent/caregiver, adopted children, other), blood relatives (i.e. biological mother, father, grandparents, sibling, children, other) of people diagnosed with “CFS” using the Fukuda criteria were found to have significantly higher rates of: Diabetes (42% – it was not clear from the paper whether this was type 1, type 2, or both)Lupus (7%) Fibromyalgia (15%)ME/CFS (5.3%) This study asked participants “have any of your relatives been diagnosed with the following medical conditions” “diabetes, Lupus, Multiple Sclerosis, Fibromyalgia, and ME/CFS”– no ME/CFS diagnostic criteria were used. |
| Torres-Harding, Jason and colleagues (2011) | Family members of those “who were classified by independent physician review as having chronic fatigue syndrome” had higher rates of metabolic/endocrine disorders (50%) compared with controls who “screened negative for having a CFS-like illness” (28%). |
| Rangel and colleagues (2005) | Parents of children with “CFS” were more likely to have “CFS-like” diagnoses – the exact illnesses were not specified, compared to parents of children without “CFS”. |
| Smith and colleagues (2010) | Mothers of young people with “CFS” had higher physical and mental fatigue, and higher pain perception compared to controls. |
| Walsh and colleagues (2001) | Those with “CFS” were more likely to have a first degree relatives (i.e. parents, siblings or offspring) with “CFS” (4.3%) compared with controls (0.5%). |
ME Research UK notes that to date, research relating to family medical history in ME/CFS has been limited by the use of inconsistent methods to define the disease – often using CFS criteria only, small sample sizes, and varying methods to collect information on family history of illness. This limits the comparisons that can be made between research papers even when they appear to be discussing the same topic, and means that more research is needed to explore how family medical history – particularly of ME/CFS, and other chronic illnesses, may be linked to risk of developing ME/CFS.
Therefore, of interest is a paper published on the 11th April 2024 by Professor Leonard Jason, and his colleague, Sarah Ngonmedje, which builds on existing research – including that of Professor Jason’s own research team.
This new study aimed to investigate:
- Whether they could replicate existing findings that those with ME/CFS are more likely to have a family history of the disease.
- Whether symptoms of ME/CFS differ between those with, and without a family history of the disease.
What did the study do?
The researchers used data from multiple, international datasets on:
- 400 people with ME/CFS – 72 with a family history of ME/CFS.
- 414 non-ME/CFS chronic illness controls
- 241 with multiple sclerosis (MS) – 8 with a family history of ME/CFS
- 173 with post-polio syndrome (PPS) – 8 with a family history of ME/CFS
Although participants in the different datasets were diagnosed with ME/CFS using different methods, the DePaul Symptom Questionnaire (DSQ-1) – a tool which provides a uniform way of assessing ME/CFS symptoms based on both the Canadian Consensus Criteria for ME/CFS, and the Fukuda criteria for CFS, was completed by everyone who took part in the study.
The DSQ-1 enabled researchers to collect information on ME/CFS symptoms, alongside demographic data – characteristics including “age”, “race” and “gender”, and social, occupational, and medical histories.
In addition, within the DSQ-1, the question: “Have any of your family members been diagnosed with chronic fatigue syndrome or myalgic encephalomyelitis?” was used to collect information on family history. The authors stated that if participants answered “yes” to this question, they were then asked to provide more information. Notably, some participants stated that family members has “ME/CFS-like illness” rather than “ME/CFS” specifically, and this was included in the family history of ME/CFS category.
What did the study find?
As expected by the researchers, those with ME/CFS were significantly more likely to have a family history of ME/CFS compared with non-ME/CFS controls – as shown below.
Interestingly, results also showed that people with ME/CFS who had a family history of the disease had DSQ-1 scores indicating significantly higher frequency and severity of gastrointestinal symptoms, compared with those without a family history of ME/CFS.
When gastrointestinal symptoms were explored further, results showed that those with ME/CFS who had a family history of the disease had significantly higher scores relating to “abdomen/stomach pain”, and “irritable bowel problems”.
Additionally, although it was not a statistically significant difference, a higher average score for bloating was also seen in those with ME/CFS who had a family history of the disease; 54.7 compared with 46.2 in those with no family history of ME/CFS.
Notably, in this study, family history of ME/CFS did not appear to have a significant impact on any of the following; sleep, post exertional malaise (PEM), pain, or neurocognitive, immune, neuroendocrine, and orthostatic symptoms.
Discussion
In agreement with results from previous research, this study found that those with ME/CFS were more likely to have a relative with the disease compared with controls – here, this was people with either MS, or PPS.
Adding to existing knowledge, this study also identified that those with ME/CFS who had a family history of the disease were “more likely to have symptoms indicating gastrointestinal dysfunction” – including irritable bowel problems, and abdomen/stomach pain, compared to those with ME/CFS who did not have a family history of the disease.
This study used a reasonably large sample size, however, it would be beneficial to explore the effect of family history of ME/CFS on disease symptoms in a larger, and more diverse cohort of participants.
One of the limitations of this study was that family history of ME/CFS was self-reported rather than confirmed by a medical professional – it is possible that participants with ME/CFS may be more likely to be aware of, and report family who had ME/CFS – or an “ME/CFS-like” illness compared with those who do not have ME/CFS.
In addition, those with a family history of “ME/CFS-like” illness were included alongside those with a family history of “ME/CFS” – It is certainly the case that future research should differentiate between these two groups, and where possible family illness history should be confirmed using ME/CFS diagnostic criteria which include PEM, or by using medical records. Consistent use of ME/CFS diagnostic criteria would also improve the comparability of studies.
In conclusion, the authors state:
family history studies can help in better understanding predisposing factors towards ME/CFS onset and maintenance and might lead to a better understanding of this illness and the people affected by it.
The authors also recognise that further exploration of the environmental factors which may act as potential influences of ME/CFS is also required.
