Crohn's disease

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Crohn's disease

Crohn's disease also known as regional enteritis is the disease of inflammatory bowel system. The classification of Inflammatory bowel disease (IBD). Disease that fall under IBD categorization usually are identified as either ulcerative colitis or crohn's disease. Crohn's disease is a chronic ailment that affects the deeper layers of the intestinal tracts while the ulcerative colitis is limited to inner lining of the rectum and colon.


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  • Location of disease in digestive tract, image obtained from Wikipedia Commons

Chromosome location

The disease locus was just recently mapped to chromosome 16 The specific location is as follows:

Gene Identification: IL23R (also known as "interleukin 23 receptor) Cytogenetic Location: 1p31.3 Molecular Location on chromosome 1: base pairs 67,632,168 to 67,725,661[1]

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  • Locus on chromosome, image obtained from Genetics home reference.

Characteristics of the Disease

The disease begins to onset from 15 years and onwards, but isn't limited to those ages as Crohn's can infect (affect --Crohn's is not an infection so it cannot infect) anyone. As a Gastrointestinal disease, infected intestinal tissue can lead to chronic recurring periods of flare-ups linked with abdominal pain. It is common for symptoms to manifest themselves with diarrhea. Tenesmus syndrom(feeling of incomplete defication) is common with fever and fistula (abnormal connection of tissue which normally do not connect, i.e muscle tissue). Weightloss amongst patients with crohn's is common.

Often a bowl obstruction is indicated through vomiting and nausea. Surgical repair often leads to short bowel syndrom, the shortening/surgical removal of the small intestine due to malabsorption(abnormal food nutrient absorption) of the digestive tract.

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  • Images differentiating a healthy intestine vs one with Crohn's disease, image obtained from findmeacure.com.

Children with onsets of the disease are known to have growth retardation. Both Adults and children can experience weightloss and loss of appetite as a results of pain resulting from consumption of food. Development of arthritis, skin disease and consistent bleeding can lead to anemia.

Those diagnosed with Crohn's disease can lead normal healthy lives without much disturbance from the disease if adequately controlled. Major lifestyle changes include leading a healthy diet filled with proper hydration. As smoking can cause irritation and flare up symptoms, patients diagnosed with Crohn's disease are encouraged to cease smoking. An active lifestyle can combat the effects of fatigue that is common amongst patients with crohn's. Patients diagnosed are recommended to record eating habits to help identify food products that can cause flare ups, such as dairy products.

Specific Manifestation of the disease in patients: symptoms of the disease, effects on their lifestyle. Possible place to include a picture. (should have deleted that sentence!)


Treatment or Management of the Condition

There presently is no cure for chrohn's disease, but treatments is available to reduce symptoms of the disease and to keep the disease in remission. Most common drugs include anti-inflammatory drugs, immuno-suppressing drugs, drugs that inhibit tumor Necrosis factor (cytokine known to induce inflammatory responses)

However, a new study shows that helminths - intestinal worms, are used as effective treatments to reduce the symptoms of crohn's disease. By having these worms colonize in the intestines, it allows the natural defenses of the body to react to the infection instead of attacking itself. [3] This research was from 2004, are there any follow up studies?


Molecular Genetics

Crohn's disease as a pathogen is heavily dependent on environment and genetics. Studies have shown the disease to be commonly found in familial environments passed down to offspring.


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  • Identifiying genetic similarities in base pairs among those infected with Crohn's disease. Image obtained from Science direct.


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  • Identifying genome wide scans to show areas of linkage in Crohn's disease. Obtained from science direct

The location of Crohn's disease as be identified as a locus on cromosome 16q12:IBd1(Inflammatory bowel disease (IBD)). Further testing through genome-wide scanning (GWS) determined further gene identification. Initially named nucleotide oligomerisation domain 2 (NOD)(NOD2 is a known gene which encodes for a protein that regulates apoptosis, programed cell death)[2], it was renamed caspase activating recruitment domain 15 (CARD), also located on chromosome 16. Analyzing controlled studies of the genes in Crohn's disease patients showed that both NOD2 and CARD15 were frame-shift mutation. Further testing determined crohn's the result of three total mutations, two missense mutations R702W and G908R, and a frameshift mutation 1007fs. The disease causing mutations were located in the leucine-rich region of the gene.[4]

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  • Showing location of mutation in chromosome 16 for crohn's disease. Obtained from science direct

The genetic products of these were identified to be primarily found in epithelial cells, further identified later to be intestinal epithelial cells in the small and large intestine responsible for the secretion of anti-bacterial substances and enzymes.

Genetic Testing

Genetic testing is available with programs such as deCODEme which provide scans for variations in the chromosome and pairing them with known combinations of Crohn's disease.


Other relevant information

Crohn's disease found in both men and women with a portion of those diagnosed having pre-existing blood relative history. Those of jewish decent have higher risks of developing this disease. With about one million American's suffering from IBD, 50 % of them suffer from Crohn's disease. 585406-fig1.jpg

  • Analysis of the growth of Inflammatory Bowel disease of both Crohn's Disease (CD) and Ulcerative Colitis (UC).

References

[1]http://ghr.nlm.nih.gov/gene/IL23R

[2]https://www.23andme.com/health/Crohns-Disease/

[3]http://www.webmd.com/ibd-crohns-disease/news/20040519/wormy-cocktail-fights-crohns-disease

[4]http://www.sciencedirect.com/science/article/B6VS0-4C76HDW-1/2/d89b9315edab81ea20be22a389abc6cd




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