title: Allele frequency of thiopurine methyltransferase and inosine triphosphate pyrophosphatase gene polymorphisms in Korean patients with inflammatory bowel diseases.
abstract: OBJECTIVE
  Adverse reactions to thiopurines may be predisposed by thiopurine methyltransferase (TPMT) or inosine triphosphate pyrophosphatase (ITPA) gene mutations.
  
  
  METHODS
  We examined the frequencies of TPMT and ITPA gene polymorphisms in 812 Korean patients with inflammatory bowel diseases using denaturing high performance liquid chromatography and direct sequencing.
  
  
  RESULTS
  The allele frequencies of TPMT*2, TPMT*3A, TPMT*3B, and TPMT*3C were 0, 0, 0, and 0.010 (17/1624), respectively. For the ITPA polymorphism, 173 subjects were heterozygous and 5 were homozygous for the 94C>A missense mutation (allele frequency of A, 0.113). Moreover, the 87T>C, IVS2+21A>C, and IVS2+53C>T polymorphisms were found in one patient each (1/1624), respectively. Of these, 87T>C and IVS2+53C>T were novel single nucleotide polymorphisms of the ITPA gene whose clinical significance should be further evaluated.
  
  
  CONCLUSIONS
  Our data describe TPMT and ITPA gene mutation patterns among Koreans and provide a basis for screening studies to identify patients at high risk for myelotoxicity from thiopurine drugs.
authors: Department of Internal Medicine and Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea.
authors: Jae Hee
authors: JH
authors: Cheon
authors: Jae Hak
authors: JH
authors: Kim
authors: Bo Young
authors: BY
authors: Kim
authors: Seung Won
authors: SW
authors: Kim
authors: Sung Yi
authors: SY
authors: Hong
authors: Chang Soo
authors: CS
authors: Eun
authors: Seong Soo
authors: SS
authors: Hong
authors: Jeong-Sik
authors: JS
authors: Byeon
authors: Tae Il
authors: TI
authors: Kim
authors: Dong Soo
authors: DS
authors: Han
authors: Suk-Kyun
authors: SK
authors: Yang
authors: Kyoung Ryul
authors: KR
authors: Lee
authors: Won Ho
authors: WH
authors: Kim
mesh_terms: D000483:Alleles; D044466:Asian People / Q000235:genetics; D001379:Azathioprine / Q000009:adverse effects; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005787:Gene Frequency; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics*; D008297:Male; D015122:Mercaptopurine / Q000009:adverse effects; D008780:Methyltransferases / Q000235:genetics*; D020125:Mutation, Missense; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D011755:Pyrophosphatases / Q000235:genetics*; D000097630:Inosine Triphosphatase
chemical_list: D001379:Azathioprine; D007166:Immunosuppressive Agents; D015122:Mercaptopurine; D008780:Methyltransferases; D011755:Pyrophosphatases; D000097630:Inosine Triphosphatase; C022745:thiopurine methyltransferase