Re: Is there a way that a genetic disease, like porphyria, could contagious ?

Hello,

Thanks for your question. 

I think the best advice I can give about writing stories with a science
base
is to read about and understand the science you want to incorporate.

By even asking this question, you have made it clear want to get the
science
right in your story, which is great. 

Learning about the science is a large undertaking, but all the good science
novels I have ever read were written by people who had a good foundation in
the area of science they were using within their stories. 

Have you read much about porphyria yet? The term encompasses a group of
metabolic disorders that result from defects in the biosynthesis of heme.
There are many types including 4 acute types,  each of which represents a
distinct genetic disorder. Some porphyrias are autosomal dominant, (i.e.
you
only need to inherit the defect from one parent in order to be affected),
and
others are autosomal recessive (i.e. you need to inherit the defect from
both
parents in order to be affected). The onset of these different types varies
also, ranging from early childhood, to puberty, to adulthood. The symptoms
of
the various disorders can be quite different. 

Genetic disorders in general cannot be contagious. However, there can be
triggers for an attack of a particular disease that one is predisposed to.
In
the case of porphyria, attacks can be triggered by the ingestion of certain
drugs or hormones, or can be precipitated by fasting and dieting. Again,
this
probably varies for different types of porphyrias. 

So, in short, if we were to take the scenario you outlined in your
question,
I imagine you would have to have most people susceptible to the effects of
a
particular disease causing agent. The disease could have the symptoms you
wanted (though make sure to check the biology of what you decide upon!). In
this case, you might be able to incorporate the symptoms of porphyria you
were
thinking of originally. 

For example, perhaps a virus or bacteria could infect humans, and cause a
vast overproduction of some compound that then causes sickness and/or
death?
In such a scenario, be sure to think about how the disease is transmitted
from
person to person, (e.g. is it inhaled, is it via touch, is it sexually
transmitted, is there another host involved, for example an insect that
transmits a pathogen, etc.), and how long the disease takes to cause death,
or
illness, etc. Reference to a basic textbook on epidemiology may help you
get
an idea of what to consider when "creating" a disease that might be
universally
contagious and which could go on to infect a large percentage of the
population.

If your background in science is not yet strong, perhaps a good idea would
be
to read a bit about diseases that have wrought devastation in the past. For
example, the Great Plague or the Influenza pandemic just after the first
world
war. The history of such diseases may be helpful in planning a story such
as
yours.

If you are looking for books on the subject of Plagues, just searching any
book selling web site with the word "plague" should bring up more than
enough
titles. Perhaps your college library will stock at least some of these. 


Good luck with your writing!