Re:Mother-inlaws environment (layman's version)

[Guest guest]

Environmental triggers ....Do Mother inlaws fall under environmental insults?....Sorry I just had to post it.....(I start back to work monday)

Peace and prayers to us all

Don

To: Sent: Sunday, February 8, 2009 2:32:32 PMSubject: Re: Genes and environment in multiple sclerosis (layman's version)

I’ll take a shot at it. These are clearly NOT written for the layman, but if you spend some time researching, you can pretty much figure it out. I’ll provide links (Wikipedia) to some of the terms. It’s not nuclear physics; I wish – would be a lot simpler, for me!

points out that we’ve many times heard that PSC is an autoimmune disease with genetic components, probably triggered by some environmental insult. In other words, susceptibility to PSC results from a combination of genes you inherited from your parents, along with some sort of environmental trigger. Environmental triggers can be many things; sunlight, malnutrition, chemicals, allergens, disease organisms, etc. As Chaim stated, the prevalence of PSC in Scandinavians might lead one to think that Vitamin D deficiency may be one trigger for PSC (ther are probably more than one).

Now for the translation (bold italics). J

“Multiple sclerosis (MS) is a complex trait in which allelic variation in the MHC class II region exerts the single strongest effect on genetic risk.” We think we know the location of the main genes associated with MS. MHC class II complex “Encodes heterodimeric peptide-binding proteins and proteins that modulate antigen loading onto MHC class II proteins in the lysosomal compartment such as MHC II DM, MHC II DQ, MHC II DR, and MHC II DP” (http://en.wikipedia .org/wiki/ Major_histocompa tibility_ complex). I encourage you to look at the links – you’ll see things like digestive enzymes, antigens (think immune system) and graft vs host disease (again, immune system).

“Epidemiological (http://en.wikipedia .org/wiki/ Epidemiology) data in MS provide strong evidence that environmental factors act at a population level to influence the unusual geographical distribution of this disease. Growing evidence implicates sunlight or vitamin D as a key environmental factor in aetiology.” Based on the epidemiological studies of MS, it looks like vitamin D (deficiency) may be an environmental trigger for MS.

“We hypothesised that this environmental candidate might interact with inherited factors and sought responsive regulatory elements in the MHC class II region. Sequence analysis localised a single MHC vitamin D response element (VDRE) to the promoter region of HLA-DRB1. Sequencing of this promoter in greater than 1,000 chromosomes from HLA-DRB1 homozygotes (http://en.wikipedia .org/wiki/ Homozygotes) showed absolute conservation of this putative VDRE on HLA-DRB1*15 haplotypes (http://en.wikipedia .org/wiki/ Haplotypes). In contrast, there was striking variation among non-MS-associated haplotypes.” We thought that vitamin D might be the culprit, and confirmed a relationship with DNA studies (genes again).

This abstract on MS, genes and environment concludes with “These findings support a connection between the main epidemiological and genetic features of this disease with major practical implications for studies of disease mechanism and prevention.” That is, they’ve shown a connection between the genetics and epidemiology of MS. If you can show that connection, you’re on the track to treatment and cure. This will NOT be easy or fast, but it constitutes a major breakthrough (for MS).

See – nothin’ to it! J

Arne

UC 1977, PSC 2000

Alive and well in Minnesota

…It is frustrating being so excited about some great news or a possible break thru and not being able to understand it…