Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022104 (irritable bowel syndrome)
 8,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gastrointestinal (GI) symptoms including nausea, vomiting, diarrhea, constipation, abdominal discomfort/pain, and heartburn are ubiquitous and as such are often the focus of nursing interventions. The etiologies of these symptoms include GI pathology (e.g., cancer, inflammation), dietary factors (e.g., lactose intolerance), infection, stress, autonomic nervous system dysregulation, medications, as well as a host of diseases outside the GI tract. This review focuses on a common condition (irritable bowel syndrome [IBS]) that is linked with both bowel pattern and abdominal discomfort/pain symptoms. Family and twin studies give evidence for a role of genetic factors in IBS. Whether genes are directly associated with IBS or influence disease risk indirectly by modulating the response to environmental factors remains unknown at this time. Given the multifactorial nature of IBS, it is unlikely that a single genetic factor is responsible for IBS. In addition, gene-gene (epistatic) interactions are also likely to play a role. Four genes coding for proteins involved in neurotransmission (i.e., the serotonin reuptake transporter [SERT], tryptophan hydroxylase [TPH], alpha2-adrenergic receptor [alpha2-ADR], catechol-o-methyl transferase [COMT]) and their potential relevance to GI symptoms and IBS will be reviewed. Further research using genome-wide association approaches with samples well characterized by ethnicity and standardized symptom subgrouping is needed.
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PMID:Genetics and gastrointestinal symptoms. 2289 8

Fatigue is the most common extraintestinal symptom in women with irritable bowel syndrome (IBS). Genetic polymorphisms of monoamines are associated with fatigue in many chronic diseases. In this pilot exploratory study, the primary aim was to determine whether genetic polymorphisms of tryptophan hydroxylase ( TPH1/TPH2), serotonin reuptake transporter ( SERT), or catechol-O-methyltransferase ( COMT) are associated with fatigue in women with IBS. Additionally, analysis explored whether these genetic associations with fatigue would be present when controlling for abdominal pain, psychological distress, feeling stressed, and sleepiness during the day. Secondary analysis of two randomized controlled trial baseline data sets in Caucasian women with IBS ( N = 185) was conducted. Participants kept a daily diary with one dimension (i.e., severity) for each of the 26 symptoms, including fatigue, for 28 days prior to randomization. DNA samples were tested for single-nucleotide polymorphisms (SNPs) of TPH1 (four SNPs) /TPH2 (one SNP), SERT (one SNP), and COMT (one SNP). Analysis of covariance was used to examine associations of percentage of diary days with moderate to very severe symptoms with genetic polymorphisms. Only one SNP, TPH2 rs4570625, was significantly associated with fatigue ( p = .005). T-allele (low functional) carriers of TPH2 (i.e., G/T or T/T genotypes) reported a greater percentage of days with moderate to very severe fatigue than G/G homozygotes ( p = .001). Reduced synthesis of tryptophan in the central nervous system may contribute to reports of fatigue in women with IBS. Understanding genetic risk factors for fatigue may elucidate preemptive strategies to reduce fatigue in individuals with IBS.
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PMID:Association of Fatigue With TPH2 Genetic Polymorphisms in Women With Irritable Bowel Syndrome. 3030 44