Running out of time: NEED annotations and notes for this article. Article Reading #1: From an article entitled “Genes, s

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Running out of time: NEED annotations and notes for this
article.
Article Reading #1: From an article entitled “Genes,
smoking, and lung cancer”
Years of study and a mountain of evidence point to tobacco smoking
as the single
most important risk factor for lung cancer. Nonsmokers (people who
have smoked fewer
than 100 cigarettes over the course of their lives) have less than
a 1% chance of ever
developing lung cancer. Smokers, on the other hand, have about a
14% chance of
developing lung cancer at some point during their lifetime—that
means their risk is more
than ten times higher than that of nonsmokers! But is smoking the
only factor that
increases a person's risk of lung cancer? The short answer is no,
as genetics has been
shown to play a role as well.
What specific genetic factors are involved in an increased risk of
lung cancer? In
recent years, three independent groups of international scientists
have identified a region
on chromosome 15 that, if mutated, dramatically increases a
smoker's risk of developing
lung cancer by another 30% to 80% (giving smokers who carry this
mutation an overall
lung cancer risk of about 20% to 23%), depending on whether an
individual has one or
two copies of what the researchers are calling the 15q24
susceptibility locus.
In general, a susceptibility locus is a region on a given
chromosome where
mutations that affect one or more genes are suspected to be
present, based on statistical
evidence. These mutations can be located in coding segments of one
or more genes,
therefore directly affecting gene products, or they may be found in
sequences that control
gene function (known as regulatory regions).
...... Data were collected on both lung cancer patients and people
without lung cancer, as
well as on both smokers and nonsmokers. All three groups of
researchers eventually
zeroed in on the same section of DNA: the long arm of chromosome
15, a region that
encodes several genes, including a few that code for nicotinic
acetylcholine receptors.
These receptors bind to nicotine and nicotine derivatives and are
found on cells in the
nervous system, in the lungs, and elsewhere in the body