Association between ADHD and DAT1 (more interesting title and don’t
use ADHD and DAT1, readers don’t know what it is yet)
ADHD is Attention Deficit Hyperactivity Disorder is a very
common childhood disorder that affects many children and young
adults, and leaves by adulthood. (why is ADHD so bad?)The exact
cause of ADHD is unknown to even the top specialists in the field
today, but through experiments, we are getting closer to finding out. It
is characterized by inattentivity, hyperactivity, and impulsitivity, or a
combination of each. Scientists in the field believe that genetics and
heredity may be a cause of ADHD and one such gene that they are
closely studying is the Dopamine Transporter gene (DAT1). The
Dopamine Transporter gene is a gene which contains many
polymorphisms (genetic variations in the gene).(how does
polymorphisms relate to ADHD? Do these genes control ADHD?) Many
significant associations have been found between the DAT1 and ADHD
by top scientists in the field such as E.H. Cook Jr. and S.V. Faraone.
(any citations for this paragraph?)
The Dopamine Transporter Gene has been related in many
studies to Attention Deficit-Hyperactivity Disorder with its
polymorphisms(confusing). The promoted polymorphism -67A/T has
been found to have a significant association with the disorder (Xu et.
al, 2009). It is found in the tight LD in the DAT1 promoter region that
is usually related to potential transcriptional recognition sites. There
have also been other independent risk variants at the 5' end of the
gene. In the experiment, Taiwan and UK found that there was an overtransmission of the -67T allele and a preferential transmission of the 67T/-839T haplotype. Through this association between the two, the
scientists can conclude that there is a definite relationship between
these two factors. You have to explain the promoter, transcription, 5’,
alleles, etc before you can start saying what they do. Give some
background to polymorphism genes and how they work.
Many experiments have also been done on the 40-bp VNTR
polymorphism. These experiments also examine its connection with
the disorder and many tests have concluded that there is a
relationship between the two. (you don’t have to take mine, but break
the sentence up and use something less confusing)The 40-bp VNTR
polymorphism stands for the 40 base-pair variable number of tandem
repeat sequence in the 3' untranslated region (3' UTR) of the gene,
varying between 3 and 11 copies, of which only the 9-repeat and the
10-repeat alleles are common. (too scientific, do you really need all
this for the reader to understand adhd?)For example, in Laucht et. al,
2007, an experiment was done suggesting that there was an
association between this and those individuals who were exposed to
psychosocial adversity and in that experiment, the results that were
found was that psychosocial adversity had an effect on how great the
intensity of the inattention and hyperactivity-impulsitivity was in these
children from the Rhine-Neckar Region of Germany. Through the many
experiments and tests done on this region of the Dopamine
Transporter Gene, where the majority of them turned up positive,
scientists can safely assume that the 40-bp VNTR polymorphism
affects ADHD in some way shape or form.
The Dopamine D4 Receptor (DRD4) is found in the frontalsubcortical networks implicated in the pathophysiology of ADHD and is
a tandem repeat polymorphism in Exon III of DRD4 (Faraone et. al,
2005). It was found in each case that the 7-repeat allele produce a
blunted response to dopamine (Faraone et. al, 2001b). Positive casecontrol studies with DRD4-7 have also been documented in the United
States of America (Grady et. al, 2003) and Brazil (Roman et. al,
2001). A family-based study also found evidence of the association
between DRD4-7 and ADHD in the United Kingdom and Ireland
(Holmes et al 2002).
It is believed that sometime in the near future, scientists will find
a way to cure ADHD starting with finding the cause. This cause could
very well be related to the genetics. This will all bring about a wave of
new findings once the aetiology (what is this word?)of the disease is
better known to today's scientists and soon, not only will Attention
Deficit-Hyperactivity Disorder be common, but it will also have a cure
and people will be able to scoff it off as if it were nothing (like a
common cold). When that day comes around, all these scientists will
be able to claim some part of the pride and honor in having cured a
disease that affects hundreds of millions of people all over the world.
I don’t think your essay is long enough. Its less than 700 words. The whole essay was
pretty scientific. You’ll need to add a lot of background information. You talk about the
connection between the two, but you have to make it understandable. Maybe use
everday comparisons. Explain further how this connection may actually cure ADHD.
Proofread and careful about run on sentences.
Yellowduck1
References
Cook Jr., E.H., Stein, M.A., Krasowski, M.D., Cox, N.J., Olkon, D.M.,
Kieffer, J.E., Leventhal, B.L. (1995) Association of AttentionDeficit Disorder and the Dopamine Transporter Gene. Am. J.
Hum. Genet. 56, 993-998
Faraone, S.V., Perlis, R.H., Doyle A.E., Smoller, J.W., Goralnick, J.J.,
Holmgren, M.A., Sklar, P. (2005). Molecular Genetics of
Attention-Deficit/Hyperactivity Disorder. Biological Psychiatry,
57:1313-1323
Faraone, S.V., Doyle, A.E., Mick, E., Biederman, J. (2001b). Metaanalysis of the association between the 7-repeat allele of the
dopamine d(4) receptor gene and attention deficit hyperactivity
disorder. Am J Psychiatry, 158:1052-1057
Grady, D.L., Chi H.C., Ding, Y.C., Smith, M., Wang, E., Schuck, S., … &
Moyzis R.K. (2003). High prevalence of rare dopamine receptor
D4 alleles in children diagnosed with attention-deficit
hyperactivity disorder. Mol Psychiatry, 7:718-725
Holmes, J., Payton, A., Barrett, J., Harrington, R., McGuffin, P., Owen,
M., …& Thapar, A.(2002). Association of DRD4 in children with
ADHD and co morbid conduc problems. Am J Med Genet
114:150-153
Laucht, M., Skowronek, M.H., Becker, K., Schmidt, M.H., Esser, G.,
Schulze, T.G., Rietschel, M. (2007). Interacting Effects of the
Dopamine Transporter Gene and Psychosocial Adversity on
Attention-Deficit/Hyperactivity Disorder symptoms Among 15Year-Olds From a High-Risk Community Sample. Arch Gen
Psychiatry, 64:585-590
Roman, T., Schmitz, M., Polanczyk, G., Eizirik, M., Rhode, L.A., Hutz,
M.H. (2001). Attention-deficit hyperactivity disorder:A study of
association with both the dopamine transporter gene and the
dopamine D4 receptor gene. Am J Med Genet, 105:471-478
Xu, X., Mill, J., Sun, B., Chen, C., Huang, Y., Wu, Y., & Asherson, P.
(2009). Association Study of Promoter Polymorphisms at the
Dopamine Transporter Gene in Attention Deficit Hyperactivity
Disorder. BMC Psychiatry, 9:3-8