Rapid allelic discrimination by TaqMan PCR for the detection of the Gilbert's syndrome marker UGT1A1*28.
Gilbert's syndrome causes mild, unconjugated hyperbilirubinemia and is present in approximately 10% of the Caucasian population. The basis of the disorder is a 70% reduction in bilirubin glucuronidation catalyzed by the UDP-glucuronosyltransferase 1A1 (UGT1A1), which, in Caucasians, is the result of a homozygous TA insertion into the promoter region of the UGT1A1 gene (UGT1A1*28). Homozygous carriers of UGT1A1*28 as well as those with additional UGT1A variants can suffer from severe irinotecan toxicity or jaundice during treatment with the protease inhibitor atazanavir. UGT1A1*28 genotyping identifies patients at risk for drug toxicity and can increase drug safety by dose individualization. Rapid and facile UGT1A1*28 genotyping is therefore of great clinical importance. Two hundred ninety-one patients with suspected Gilbert's syndrome were genotyped using the TaqMan 5'nuclease assay with minor groove binder-non fluorescent quench probes; results were confirmed by direct sequencing. Ninety-six patients (33%) were homozygous for UGT1A1*28, which was verified by direct sequencing of a different PCR product showing 100% concordance with the TaqMan PCR results. We describe a novel UGT1A1*28 genotyping method that employs allelic discrimination by TaqMan PCR. This assay provides a rapid, high-throughput, and cost-effective method for Gilbert's syndrome genotyping, which is of value for pretreatment screening of potential irinotecan toxicity. The method utilizes a technological platform that is widely used in clinical practice and could therefore be easily adapted for routine clinical applications.
Ehmer
Ursula
U
Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
Lankisch
Tim O
TO
Erichsen
Thomas J
TJ
Kalthoff
Sandra
S
Freiberg
Nicole
N
Wehmeier
Michael
M
Manns
Michael P
MP
Strassburg
Christian P
CP
D000368:Aged; D000483:Alleles; D004252:DNA Mutational Analysis / Q000379:methods*; D005260:Female; D005819:Genetic Markers; D005838:Genotype; D005878:Gilbert Disease / Q000235:genetics*; D014453:Glucuronosyltransferase / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods*; D011401:Promoter Regions, Genetic / Q000235:genetics; D000099148:UGT1A1 Enzyme
D005819:Genetic Markers; D014453:Glucuronosyltransferase; D000099148:UGT1A1 Enzyme