Hi Heather,
From what i have seen the 7t genotype is normal and and the 5t genotype is responsible for pancreatitis. I will post the following abstracts. I don't know much. I'm sure steve and your docs will know more but hopefully this will help ease your mind some.
The following abstract states that the 7t and 9t polymorphisms are normal genotypes while the 5t is assoiciated with idiopathic pancreatitis (BUT not necessarily alcholic pancreatitis).
Alcoholic pancreatitis and polymorphisms of the variable length polythymidine tract in the cystic fibrosis gene.
* Haber PS,
* Norris MD,
* Apte MV,
* Rodgers SC,
* Norton ID,
* Pirola RC,
* Roberts-Thomson IC,
* Wilson JS.
Department of Gastroenterology, Prince of Wales Hospital, Sydney, Australia.
BACKGROUND: The observation that only a minority of alcoholics develops clinical pancreatic disease has led to a search for a predisposing factor to the disease. One possible predisposing factor is mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene as cystic fibrosis leads to pancreatic injury. We have recently demonstrated that 15 common CFTR mutations are not found in patients with alcoholic pancreatitis. Another common polymorphism of the CFTR gene has recently been implicated in the pathogenesis of idiopathic chronic pancreatitis, the 5T variant of the variable length polythymidine tract in intron 8 (the normal genotypes are 7T and 9T). The 5T variant inhibits transcription of exon 9 resulting in a CFTR protein lacking chloride channel activity. The aim of this study was to determine whether the 5T variant is associated with alcoholic pancreatitis. METHODS: Fifty-two patients with alcoholic pancreatitis were identified using standardized diagnostic criteria. Fifty alcoholics without pancreatitis were also studied as controls. Genomic DNA was extracted from peripheral blood leukocytes and the polythymidine tract of intron 8 was amplified by nested polymerase chain reaction using established primers. The polymerase chain reaction products were digested with MseI, separated by electrophoresis on 15% polyacrylamide gels and genotypes assigned by comparison with known positive controls. RESULTS: The 5T allele we found in only two patients with alcoholic pancreatitis (3.9% of th index group; 95% confidence intervals 0-10%) and in seven alco holic controls. Allele frequencies for 5T, 7T, and 9T in patients with alcoholic pancreatitis were 1.9%, 85.6%, and 12.5%, respectively These did not differ from the allele frequencies in alcoholic controls (7%, 79%, and 14% for 5T, 7T, and 9T, respectively). CONCLUSION: The 5T allele was not associated with alcoholic pancreatitis. Individual susceptibility to this disease remains unexplained.
Here is another link where the most common allele in japan, the 7t, is associated with healthy people not people with pancreatitis.
Links
Polymorphism of cystic fibrosis gene in Japanese patients with chronic pancreatitis.
* Kimura S,
* Okabayashi Y,
* Inushima K,
* Yutsudo Y,
* Kasuga M.
Second Department of Internal Medicine, Kobe University School of Medicine, Japan.
Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and the 5T genotype of the polythymidine tract at the exon 9 splice branch/acceptor site are shown to be associated with chronic pancreatitis in Caucasian patients. In contrast to Western countries, cystic fibrosis is extremely rare in Japan. In this study, we investigated the association of mutations or polymorphisms of the CFTR gene with chronic pancreatitis in Japanese patients. Forty-seven patients with chronic pancreatitis (alcohol-related in 31, idiopathic in 14, and familial in 2) were examined for the deltaF508 and R117H mutations and polymorphisms of intron 8. DNA was extracted from leukocytes. Mutations and polymorphisms were examined by the allele-specific polymerase chain reactions and confirmed by direct sequencing. None of the patients had deltaF508 or R117H mutations in the CFTR gene. All of 47 healthy Japanese showed the homozygous 7T/7T genotype, whereas the frequencies of 5T, 7T, and 9T alleles were 0.043, 0.894, and 0.064 in the patients, respectively. The difference in allele frequency is statistically significant. Therefore, the present study indicates the association of polymorphism of the polythymidine tract in intron 8 of the CFTR gene with chronic pancreatitis in Japanese patients.
PMID: 11117575 [PubMed - indexed for MEDLINE]
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