In case you haven't seen it, there is much in the news these days regarding a new study that has found a genetic link to MS in women, and that women are being diagnosed with MS twice as often as men. The study, funded by the MS Society in the UK, was conducted at Oxford, and headed up by professor George Ebers.
The mystery of why multiple sclerosis predominantly strikes women may have been unraveled a bit, thanks to a new genetic study.
Polymorphisms in major histocompatibility complex (MHC) genes and their associated DNA methylation patterns may combine with environmental influences in ways that promote greater susceptibility to the disease in women than in men, according to George C. Ebers, MD, FMedSci, of John Radcliffe Hospital in Oxford, England, and colleagues.
Published online in Neurology, their findings were based on genomic analyses of more than 7,000 members of 1,055 families affected by MS. Ebers and colleagues noted that, 100 years ago, MS was reported to affect men and women about equally. However, in their sample, of the more than 2,100 individuals who had MS, 73% were female. They noted that published reports from around the world point to an approximate 2:1 ratio of female versus male MS patients.
MS risk is believed to have a strong heritable component centered on MHC genes, but the reason for the female predominance has been unclear. Previous studies have ruled out genes carried on the X chromosome as contributing significantly to MS. Consequently, Ebers and colleagues sought to identify genetic or epigenetic factors related to MHC genes elsewhere in the genome that might also have discrepant associations with gender.
http://www.medpagetoday.com/clinical-context/MultipleSclerosis/24207
I am going to make a supposition. Rather than assert that MS rates are growing in the female population--perhaps the fact is that we know more about MS than we did 100 years ago, and more mild, earlier or benign cases of MS in women are now detected, thanks to MRI imaging and the McDonald criteria.
Or, perhaps, MS rates truly are increasing for women, and new environmental issues are affecting women more seriously than men. Whatever the connection, I'd like to point out the current correlation to chronic venous disease:
Just as in MS, women are affected 2 times more than men in chronic venous disease.
Here is a recent study of Chronic Venous Disease (CVD) This is chronic disease in the leg veins. Read this study, and see if anything looks familiar to you. It did to me.....
Heritability of chronic venous disease
http://www.acfas.org/Physicians/Content.aspx?id=2118
2,701 patients with chronic venous disease (CVD) were recruited between October 2005 and July 2008 at a vascular clinic in Germany specializing in the treatment of CVD. A questionaire was given to each patient to obtain information including age, race, sex, date and place of birth, and parental origin. Medical history was also obtained and included information such as previous treatment, degree of pain, age of onsent of CVD, previous surgeries, previous deep vein thrombosis or phlebitis. A blood sample was taken from each patient for further genetic analysis.
Overall mean age at CVD onset was noted to be 32.6 years. An inverse relationship was noted in this study between disease severity and disease onset. Patients affected by less severe grades of CEAP classification (grades C0 to C2) were first affected by CVD at 35.8 years compared with grades C3 to C6 which were affected at 30.7 years. A drastic increase in disease duration and disease severity was observed in the study. No significant age difference was observed between males and females. In reference to sex itself, twice as many patients involved in the study were female (1,904). Age of disease onset was 30.8 years in females and 36.8 years in males
Conclusions:
The main risk factors identifiable with CVD to date have been female sex, age and family history. This is the first study to include age at disease onset and disease duration. Results from this study confirm previouslyl proposed hypotheses. For example, it has been previously reported that there is a larger number of female patients with CVD. This gender predilection can be explained by numerous reasons including the fact that women are more likely to seek medical attention and undergo treatment than men. Also, as observed by this study, disease onset was approximately 6 years earlier in females. The inverse relationhip observed between severity could be explained by the fact that CVD is a progressive disease which can cause those with longer disease duration to demonstrate the worst phenotype. BMI was noted to be statistically significant between males and females in this study, Previous chronic venous disease studies have reported that BMI is more important in females than males. However, the current study also discovered that obesity can play a larger role in the development of more severe forms of CVD.
It can be concluded from this study that there is a true genetic compontent to CVD. Additional studies could determine if the results of this study correspond with CVD in the international population. It may be possible for specific genes affecting vascular supply to the lower extremity can be identified with futher genetic analysis.
Here again is Dr. Ferlini's genetic study, where she found CCSVI and MS share copy number variations on the same HLA locus region that is associated with MS.
http://www.fondazionehilarescere.org/pdf/ferlini-etal-2010-final.pdf
The CNVs contained in the HLA locus region in patients with the novel phenotype of CCSVI/VM and MS
were mapped in detail, demonstrating a significant correlation between the number of known CNVs found in the HLA region and the number of CCSVI-VMs identified in patients. Pathway analysis revealed common routes of interaction of several of the genes involved in angiogenesis and immunity contained within this region.
Dr. Ebers....Please, I beg you. Consult with vascular doctors like Dr. Paolo Zamboni and Dr. B.B. Lee and geneticists like Dr. Ferlini for your continuing MS studies at Oxford. The answers are here, they are being uncovered, but you are going to need to look outside the autoimmune box and broaden your studies.
In summary---
1. MS and chronic venous disease occur twice as often in women as men.
2. There is a genetic link to both MS and CVD
3. CCSVI and MS share copy number variations on the HLA locus associated with MS
4. Environmental issues appear to affect severity of MS and CVD
5. Both MS and CVD are chronic progressive diseases, which worsen with age and disease duration
6. Age of onset of CVD and MS occurs in young adults