View Full Version : Genes create susceptability to Meningitis

08-09-2010, 11:54 AM
Genetic Differences That Make Some People Susceptible to Meningitis Revealed in Major New Study (http://www.sciencedaily.com/releases/2010/08/100808212802.htm)

Although most of us have carried the meningitis bacteria at some point, only around one in 40,000 people develop meningococcal meningitis. Our study set out to understand what causes this small group of people to become very ill whilst others remain immune. Our findings provide the strongest evidence so far that there are genetic factors that lead to people developing meningitis.

...meningococcal bacteria can hijack the body's Factor H and use it to ensure that the body does not recognise the bacteria as foreign. The bacteria effectively use Factor H as a 'Trojan Horse,' enabling them to evade the body's defences and preventing the immune system from killing them.

Bacteria evolve millions of times faster than humans. Their main goal is to mutate into forms that can defeat an immune system, invade a host and reproduce. In this case bacteria have learned how to defeat some people's genetically programmed, defense mechanisms. This explains why an infectious disease like Meningitis can hit some families very hard.

It's worth noting that the newest and largest twin study on Scoliosis found a particularly low concordance rate among twins. Genes may (or may not) make a child susceptible to Scoliosis but they don't appear to cause it. The environmental component could be anything including the damage triggered by a common infection that hits almost everyone.

Adolescent idiopathic scoliosis in twins: a population-based survey. (http://www.ncbi.nlm.nih.gov/pubmed/17426641)

RESULTS: A subgroup of 220 subjects considered to have AIS was identified, thus giving a prevalence of 1.05%. The concordant twin pairs were all monozygotic. Pairwise, the concordance rate was 0.13 for monozygotic and zero for dizygotic twin pairs; proband-wise concordance was 0.25 for monozygotic and zero for dizygotic pairs. The concordance of monozygotic and dizygotic pairs was significantly different (P < 0.05). CONCLUSION: We have found evidence for a genetic etiology in AIS, but the risk of developing scoliosis in 1 twin whose other twin has scoliosis is smaller than believed up until now.