Gastroesophageal reflux disease, or GERD, has only recently
been categorized as an official disease process. Once
regarded as nothing more than severe heartburn, GERD can be
seen in people of all age groups. GERD was once thought of
as an acquired disease, meaning the disease occurs either
from injury or other influences. However, with the rise in
cases of pediatric GERD, reports of GERD being a hereditary
disease have gained momentum. |
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The following study aimed at
identifying the gene or genes that are most likely
responsible for the occurrence of GERD. Gastroesophageal
reflux involves the upward movement of stomach contents into
the esophagus due to a weakness in the muscle that closes
the entrance to the stomach. Imagine trying to tie a water
balloon, but the water keeps leaking out. Now, instead of
water, imagine the balloon is filled with stomach acids. The
stomach acids can cause irritations and damage to the
esophagus. Although this happens normally from time to time
for everyone, people who suffer from GERD deal with it much
more often and in more severe levels.
Children are far more vulnerable to GERD than adults.
Severe pediatric GERD can lead to a failure to thrive due to
malnutrition and avoidance of food. Chronic reflux can also
affect the respiratory tract, causing asthma and other
respiratory problems. Chronic GERD is also an associated
risk factor of developing Barrett metaplasia, a
pre-cancerous lesion of the esophagus. Infants are also at
risk of aspiration of stomach contents and choking. GERD has
also been implicated in sudden infant death syndrome. In
short, reflux sux. The good news is that many children
outgrow the effects of GERD between the ages of 1 and 5
years. However, us parents know that it can be a LONG 1 to 5
years. And even then, some children don't outgrow it
completely.
The aim of this study was to find a specific genetic
component as the cause of GERD. The study was performed with
the help of
PAGER (Pediatric/Adolescent Gastroesophageal Reflux
Association). Families with a history of GERD symptoms were
invited to participate.
The scientists who took part in this study searched for
the GERD gene by performing a "microsatellite marker-based
genome-wide scan." In English, they looked for the gene by
narrowing down the area in which the gene was most likely
located. The microsatellite markers attach to specific
points on human DNA. Then, by comparing the satellite
markers in those affected by GERD with those in non-affected
patients, they were able to identify where the gene is
located.
It sounds very complicated because it is. Imagine that
your car breaks down on the highway. You call a tow truck,
but you don't know exactly where you are. You do know,
however, that you started driving at mile marker 15 and you
were headed to mile marker 35. Now the tow truck driver
knows to look for you somewhere in that area. That's how
gene mapping works. Scientists (tow truck drivers) use
satellite markers (mile markers) to find specific genes (you
and your busted car) in sequences of DNA (the highway).
Once scientists find the markers in common, special
programs are used to analyze how likely that marker is
linked to the disease in question. In this particular study,
a single marker located on chromosome 13 showed strong
evidence of linkage. After further analysis too complex to
mention, the scientists were able to successfully map the
gene for severe pediatric GERD to a small region on
chromosome 13.
Now we all have a target to vent our frustration and
rage. "Well, if your chromosome 13 wasn't messed up, then
our child would be perfectly fine! Great job! Way to pass on
faulty genetics!" In all seriousness, this represents a
large leap forward in not only the diagnosis of GERD, but
the treatment as well. Presently, only treatment of the
symptoms is possible. Now that the genetic source of the
disease has been discovered, more effective therapies that
relate to the biochemical source of GERD can be developed.
Resource: American Medical Association
JAMA, July 19, 2000-Vol 284, No. 3 |
