Tag: genetic predisposition

No replication of previously reported association with genetic variants in the T cell receptor alpha (TRA) locus for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disease with a variety of symptoms such as post-exertional malaise, fatigue, and pain, but where aetiology and pathogenesis are unknown. An increasing number of studies have implicated the involvement of the immune system in ME/CFS. Furthermore, a hereditary component is suggested by the reported increased risk for disease in relatives, and genetic association studies are being performed to identify potential risk variants.

We recently reported an association with the immunologically important human leucocyte antigen (HLA) genes HLA-C and HLA-DQB1 in ME/CFS. Furthermore, a genome-wide genetic association study in 42 ME/CFS patients reported significant association signals with two variants in the T cell receptor alpha (TRA) locus (P value <5 × 10-8). As the T cell receptors interact with the HLA molecules, we aimed to replicate the previously reported findings in the TRA locus using a large Norwegian ME/CFS cohort (409 cases and 810 controls) and data from the UK biobank (2105 cases and 4786 controls).

We investigated numerous SNPs in the TRA locus, including the two previously ME/CFS-associated variants, rs11157573 and rs17255510. No associations were observed in the Norwegian cohort, and there was no significant association with the two previously reported SNPs in any of the cohorts. However, other SNPs showed signs of association (P value <0.05) in the UK Biobank cohort and meta-analyses of Norwegian and UK biobank cohorts, but none survived correction for multiple testing. Hence, our research did not identify any reliable associations with variants in the TRA locus.

Source: Ueland M, Hajdarevic R, Mella O, Strand EB, Sosa DD, Saugstad OD, Fluge Ø, Lie BA, Viken MK. No replication of previously reported association with genetic variants in the T cell receptor alpha (TRA) locus for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Transl Psychiatry. 2022 Jul 11;12(1):277. doi: 10.1038/s41398-022-02046-1. PMID: 35821115. https://www.nature.com/articles/s41398-022-02046-1 (Full text)

Antioxidant Genetic Profile Modifies Probability of Developing Neurological Sequelae in Long-COVID

Abstract:

Understanding the sequelae of COVID-19 is of utmost importance. Neuroinflammation and disturbed redox homeostasis are suggested as prevailing underlying mechanisms in neurological sequelae propagation in long-COVID. We aimed to investigate whether variations in antioxidant genetic profile might be associated with neurological sequelae in long-COVID. Neurological examination and antioxidant genetic profile (SOD2, GPXs and GSTs) determination, as well as, genotype analysis of Nrf2 and ACE2, were conducted on 167 COVID-19 patients. Polymorphisms were determined by the appropriate PCR methods.
Only polymorphisms in GSTP1AB and GSTO1 were independently associated with long-COVID manifestations. Indeed, individuals carrying GSTP1 Val or GSTO1 Asp allele exhibited lower odds of long-COVID myalgia development, both independently and in combination. Furthermore, the combined presence of GSTP1 Ile and GSTO1 Ala alleles exhibited cumulative risk regarding long-COVID myalgia in carriers of the combined GPX1 LeuLeu/GPX3 CC genotype. Moreover, individuals carrying combined GSTM1-null/GPX1LeuLeu genotype were more prone to developing long-COVID “brain fog”, while this probability further enlarged if the Nrf2 A allele was also present.
The fact that certain genetic variants of antioxidant enzymes, independently or in combination, affect the probability of long-COVID manifestations, further emphasizes the involvement of genetic susceptibility when SARS-CoV-2 infection is initiated in the host cells, and also months after.
Source: Ercegovac M, Asanin M, Savic-Radojevic A, Ranin J, Matic M, Djukic T, Coric V, Jerotic D, Todorovic N, Milosevic I, Stevanovic G, Simic T, Bukumiric Z, Pljesa-Ercegovac M. Antioxidant Genetic Profile Modifies Probability of Developing Neurological Sequelae in Long-COVID. Antioxidants. 2022; 11(5):954. https://doi.org/10.3390/antiox11050954  https://www.mdpi.com/2076-3921/11/5/954/htm (Full text)

Genetic association study in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) identifies several potential risk loci

Highlights:

• Largest ME/CFS genetic study to date.

• Three different cohorts totaling >2500 patients.

• First Immunochip study in ME/CFS.

• Possible implication of TPPP genetic region.

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disease of unknown etiology and pathogenesis, which manifests in a variety of symptoms like post-exertional malaise, brain fog, fatigue and pain. Hereditability is suggested by an increased disease risk in relatives, however, genome-wide association studies in ME/CFS have been limited by small sample sizes and broad diagnostic criteria, therefore no established risk loci exist to date.

In this study, we have analyzed three ME/CFS cohorts: a Norwegian discovery cohort (N = 427), a Danish replication cohort (N = 460) and a replication dataset from the UK biobank (N = 2105). To the best of our knowledge, this is the first ME/CFS genome-wide association study of this magnitude incorporating 2532 patients for the genome-wide analyses and 460 patients for a targeted analysis. Even so, we did not find any ME/CFS risk loci displaying genome-wide significance.

In the Norwegian discovery cohort, the TPPP gene region showed the most significant association (rs115523291, P = 8.5 × 10−7), but we could not replicate the top SNP. However, several other SNPs in the TPPP gene identified in the Norwegian discovery cohort showed modest association signals in the self-reported UK biobank CFS cohort, which was also present in the combined analysis of the Norwegian and UK biobank cohorts, TPPP (rs139264145; P = 0.00004). Interestingly, TPPP is expressed in brain tissues, hence it will be interesting to see whether this association, with time, will be verified in even larger cohorts. Taken together our study, despite being the largest to date, could not establish any ME/CFS risk loci, but comprises data for future studies to accumulate the power needed to reach genome-wide significance.

Source: Hajdarevic R, Lande A, Mehlsen J, Rydland A, Sosa DD, Strand EB, Mella O, Pociot F, Fluge Ø, Lie BA, Viken MK. Genetic association study in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) identifies several potential risk loci. Brain Behav Immun. 2022 Mar 19:S0889-1591(22)00078-2. doi: 10.1016/j.bbi.2022.03.010. Epub ahead of print. PMID: 35318112. https://www.sciencedirect.com/science/article/pii/S0889159122000782 (Full study)

Commonalities in the Features of Cancer and Chronic Fatigue Syndrome (CFS): Evidence for Stress-Induced Phenotype Instability?

Abstract:

Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) and Cancer-Related Fatigue (CRF) are syndromes with considerable overlap with respect to symptoms. There have been many studies that have compared the two conditions, and some of this research suggests that the etiologies of the conditions are linked in some cases. In this narrative review, CFS/ME and cancer are introduced, along with their known and putative mechanistic connections to multiple stressors including ionizing radiation.

Next, we summarize findings from the literature that suggest the involvement of HPA-axis dysfunction, the serotonergic system, cytokines and inflammation, metabolic insufficiency and mitochondrial dysfunction, and genetic changes in CRF and CFS/ME. We further suspect that the manifestation of fatigue in both diseases and its causes could indicate that CRF and CFS/ME lie on a continuum of potential biological effects which occur in response to stress. The response to this stress likely varies depending on predisposing factors such as genetic background.

Finally, future research ideas are suggested with a focus on determining if common biomarkers exist in CFS/ME patients and those afflicted with CRF. Both CFS/ME and CRF are relatively heterogenous syndromes, however, it is our hope that this review assists in future research attempting to elucidate the commonalities between CRF and CFS/ME.

Source: Rusin A, Seymour C, Cocchetto A, Mothersill C. Commonalities in the Features of Cancer and Chronic Fatigue Syndrome (CFS): Evidence for Stress-Induced Phenotype Instability? Int J Mol Sci. 2022 Jan 8;23(2):691. doi: 10.3390/ijms23020691. PMID: 35054876. https://pubmed.ncbi.nlm.nih.gov/35054876/

Clinically proven mtDNA mutations are not common in those with chronic fatigue syndrome

Abstract:

Background: Chronic Fatigue Syndrome (CFS) is a prevalent debilitating condition that affects approximately 250,000 people in the UK. There is growing interest in the role of mitochondrial function and mitochondrial DNA (mtDNA) variation in CFS. It is now known that fatigue is common and often severe in patients with mitochondrial disease irrespective of their age, gender or mtDNA genotype. More recently, it has been suggested that some CFS patients harbour clinically proven mtDNA mutations.

Methods: MtDNA sequencing of 93 CFS patients from the United Kingdom (UK) and South Africa (RSA) was performed using an Ion Torrent Personal Genome Machine. The sequence data was examined for any evidence of clinically proven mutations, currently; more than 200 clinically proven mtDNA mutations point mutations have been identified.

Results: We report the complete mtDNA sequence of 93 CFS patients from the UK and RSA, without finding evidence of clinically proven mtDNA mutations. This finding demonstrates that clinically proven mtDNA mutations are not a common element in the aetiology of disease in CFS patients. That is patients having a clinically proven mtDNA mutation and subsequently being misdiagnosed with CFS are likely to be rare.

Conclusion: The work supports the assertion that CFS should not be considered to fall within the spectrum of mtDNA disease. However, the current study cannot exclude a role for nuclear genes with a mitochondrial function, nor a role of mtDNA population variants in susceptibility to disease. This study highlights the need for more to be done to understand the pathophysiology of CFS.

Source: Schoeman EM, Van Der Westhuizen FH, Erasmus E, van Dyk E, Knowles CV, Al-Ali S, Ng WF, Taylor RW, Newton JL, Elson JL. Clinically proven mtDNA mutations are not common in those with chronic fatigue syndrome. BMC Med Genet. 2017 Mar 16;18(1):29. doi: 10.1186/s12881-017-0387-6. PMID: 28302057; PMCID: PMC5356238. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5356238/ (Full text)

Re-analysis of genetic risks for Chronic Fatigue Syndrome from 23andMe data finds few remain

Abstract:

It is tempting to mine the abundance of DNA data that is now available from direct-to-consumer genetic tests, but this approach has its pitfalls A recent study put forth a list of 50 single nucleotide polymorphisms (SNPs) that predispose to Chronic Fatigue Syndrome (CFS), a potentially major advance in understanding this still mysterious disease. However, only the patient cohort data came from a commercial company (23andMe) while the control was a genetic database. The extent to which 23andMe data agree with genetic reference databases is unknown. We reanalyzed the 50 purported CFS SNPs by comparing to control data from 23andMe which are available through public platform OpenSNP. In addition, large high-quality database ALFA was used as an additional control. The analysis lead to dramatic change with the top of the leaderboard for CFS risk reduced and reversed from an astronomical 129,000 times to 0.8.

Errors were found both within 23andMe data and the original study-reported Kaviar database control. Only 3 of 50 SNPs survived initial study criterion of at least twice as prevalent in patients, EFCAB4B involving calcium ion channel, LINC01171, and MORN2 genes. We conclude the reported top-50 deleterious polymorphisms for Chronic Fatigue Syndrome were more likely the top-50 errors in the 23andMe and Kaviar databases. In general, however, correlation of 23andMe control with ALFA was a respectable 0.93, suggesting an overall usefulness of 23andMe results for research purposes but only if caution is taken with chips and SNPs.

Source: Felice L Bedford, Bastian Greshake Tzovaras. Re-analysis of genetic risks for Chronic Fatigue Syndrome from 23andMe data finds few remain. Frontiers in Pediatrics, October 29. 2020. https://www.medrxiv.org/content/10.1101/2020.10.27.20220939v1.full.pdf+html  (Full study)

Genetic Predisposition for Immune System, Hormone, and Metabolic Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Pilot Study

Abstract:

Introduction: Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS) is a multifactorial illness of unknown etiology with considerable social and economic impact. To investigate a putative genetic predisposition to ME/CFS we conducted genome-wide single-nucleotide polymorphism (SNP) analysis to identify possible variants.

Methods: 383 ME/CFS participants underwent DNA testing using the commercial company 23andMe. The deidentified genetic data was then filtered to include only non-synonymous and nonsense SNPs from exons and microRNAs, and SNPs close to splice sites. The frequencies of each SNP were calculated within our cohort and compared to frequencies from the Kaviar reference database. Functional annotation of pathway sets containing SNP genes with high frequency in ME/CFS was performed using over-representation analysis via ConsensusPathDB. Furthermore, these SNPs were also scored using the Combined Annotation Dependent Depletion (CADD) algorithm to gauge their deleteriousness.

Results: 5693 SNPs were found to have at least 10% frequency in at least one cohort (ME/CFS or reference) and at least two-fold absolute difference for ME/CFS. Functional analysis identified the majority of SNPs as related to immune system, hormone, metabolic, and extracellular matrix organization. CADD scoring identified 517 SNPs in these pathways that are among the 10% most deleteriousness substitutions to the human genome.

Source: Melanie Perez, Rajeev Jaundoo, Kelly Hilton, Ana Del Alamo, Kristina Gemayel, Nancy G. Klimas, Travis J. A. Craddock and Lubov Nathanson. Genetic Predisposition for Immune System, Hormone, and Metabolic Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Pilot Study. Front. Pediatr., 24 May 2019 | https://doi.org/10.3389/fped.2019.00206 (Full article)

Evidence for a heritable predisposition to Chronic Fatigue Syndrome

Abstract:

BACKGROUND: Chronic Fatigue Syndrome (CFS) came to attention in the 1980s, but initial investigations did not find organic causes. Now decades later, the etiology of CFS has yet to be understood, and the role of genetic predisposition in CFS remains controversial. Recent reports of CFS association with the retrovirus xenotropic murine leukemic virus-related virus (XMRV) or other murine leukemia related retroviruses (MLV) might also suggest underlying genetic implications within the host immune system.

METHODS: We present analyses of familial clustering of CFS in a computerized genealogical resource linking multiple generations of genealogy data with medical diagnosis data of a large Utah health care system. We compare pair-wise relatedness among cases to expected relatedness in the Utah population, and we estimate risk for CFS for first, second, and third degree relatives of CFS cases.

RESULTS: We observed significant excess relatedness of CFS cases compared to that expected in this population. Significant excess relatedness was observed for both close (p <0.001) and distant relationships (p = 0.010). We also observed significant excess CFS relative risk among first (2.70, 95% CI: 1.56-4.66), second (2.34, 95% CI: 1.31-4.19), and third degree relatives (1.93, 95% CI: 1.21-3.07).

CONCLUSIONS: These analyses provide strong support for a heritable contribution to predisposition to Chronic Fatigue Syndrome. A population of high-risk CFS pedigrees has been identified, the study of which may provide additional understanding.

 

Source: Albright F, Light K, Light A, Bateman L, Cannon-Albright LA. Evidence for a heritable predisposition to Chronic Fatigue Syndrome. BMC Neurol. 2011 May 27;11:62. doi: 10.1186/1471-2377-11-62. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3128000/ (Full article)

 

High incidence of antibodies to 5-hydroxytryptamine, gangliosides and phospholipids in patients with chronic fatigue and fibromyalgia syndrome and their relatives: evidence for a clinical entity of both disorders

Abstract:

The fibromyalgia syndrome (FMS) is one of the most frequent rheumatic disorders showing a wide spectrum of different symptoms. An association with the chronic fatigue syndrome (CFS) has been discussed. Recently, a defined autoantibody pattern consisting of antibodies to serotonin (5-hydroxytryptamine, 5-HT), gangliosides and phospholipids was found in about 70% of the patients with FMS. We were therefore interested in seeing whether patients with CFS express similar humoral immunoreactivity.

Sera from 42 CFS patients were analysed by ELISA for these antibodies, and the results were compared with those previously observed in 100 FMS patients. 73% of the FMS and 62% of the CFS patients had antibodies to serotonin, and 71% or 43% to gangliosides, respectively. Antibodies to phospholipids could be detected in 54% of the FMS and 38% of the CFS patients. 49% of FMS and 17% of the CFS patients had all three antibodies in parallel, 70% and 55%, respectively had at least two of these antibody types. 21% of FMS and 29% of CFS patients were completely negative for these antibodies. Antibodies to 5-HT were closely related with FMS/CFS while antibodies to gangliosides and phospholipids could also be detected in other disorders.

The observation that family members of CFS and FMS patients also had these antibodies represents an argument in favour of a genetic predisposition. These data support the concept that FMS and CFS may belong to the same clinical entity and may manifest themselves as ‘psycho-neuro-endocrinological autoimmune diseases’.

 

Source: Klein R, Berg PA. High incidence of antibodies to 5-hydroxytryptamine, gangliosides and phospholipids in patients with chronic fatigue and fibromyalgia syndrome and their relatives: evidence for a clinical entity of both disorders. Eur J Med Res. 1995 Oct 16;1(1):21-6. http://www.ncbi.nlm.nih.gov/pubmed/9392689