Everyone has heard of magnetism. It is a physical force that attracts two objects together.
It surrounds us, The earth is one large electro magnet. It surrounds many objects we build like powerlines or cell phones.It is ubiquitous.
Magnetic “forces” can be observed or felt when magnets stick to other metal items, like those on fridges.The force can also be observed when two magnets are placed together but something stops them touching no matter hard you try. It is explained that the “ poles” are the same so they repel each other.Turning one magnet the other way , “reversing the poles” , results in the same magnets sticking together. Polarity is important when it comes to magnets working to attract or not.
It also exists within people too. Like all living material the body creates the electricity charge which is needed to create magnetic forces. Electromagnetivity can be found throughout the body. Most noticeably in the brain , but also at micro biological level – biomagnetivity.
Complement is known to aHUS patients because it is implicated strongly in their illness. Complement is made up of microbiological bits in the blood. Bits which stick or bind to each other, or cut or cleave other bits. Evolution has developed these microbiolical bits to follow steps in creating something which protects each of us. Cutting the right bits which then go on to stick to other right bits in the right order to destroy invading organisms that are harmful to us.
When that job is done other bits stick to the joined up bits to stop them working. If they continued I they could damage the body.
We may have seen images of these bits , crystaline structures they are called, made up of what appears to coagulated melted jelly beans or decorative coloured bunting to explain the different parts and show areas where one bit is designed stick to another. The body builds these bits consistently and replacing them continuously throughout our lives. All predetermined by our DNA.
But what if the DNA is altered as can happen when ever a living thing is created. What if that change turns something that was working properly into some thing that only partially works or does not work at all. That is a mutation or a significant variant for causing a rare disease. It’s as simple as that.
Take this signicant variant in a Complement component called Factor H. Geneticists describe it as:
c.3643C>G; p. Arg1215Gly
The numbers reflect the location within the micro biological structure of the component , I.e. one of those coloured areas of coagulated melted jelly beans. The rest says what chemical change has happened one building block ( or amino acid ) has changed to another. In this example some thing called “Arg or Argenine” is replaced by ”Gly or Glycine . You might say “so what”
Well Argenine happens to have a strong micro electricity charge or polarity. It is there to stick Complement Factor H to another Complement component using that electric charge. If it can do It successfully that it can control the activity of Complement to stop it getting out of control and doing damage to the body , as would happen in an episode of aHUS.
But for the person with this variant the switch to glycine, which has a much lower micro polarity, means it cannot stick to the other component. There is little attraction and so it cannot control complement activity. When the circumstance are right this fatal non attraction will result in aHUS.
This is not the only variant that can make some susceptible to aHUS , there are hundreds of them in Complement, each with its own description like the one above. Each can cause Complement to be uncontrolled in their own way.