Irinotecan is used for the treatment of metastatic carcinoma of the colon or rectum. It causes severe neutropenia and diarrhea in 20-35% of patients undergoing chemotherapy. The ability to predict toxicity in treated patients is an important consideration.
UGT1A1 catalyzes the inactivation of SN-38, the active and toxic metabolite of irinotecan. The 7TA repeat length polymorphism (termed *28 allele) in the UGT1A1 promoter is associated with decreased UGT1A1 gene expression levels, resulting in lower than normal UGT1A1 enzymatic activity and accumulation of SN-38, the active irinotecan metabolite.
About 15% of North Americans are homozygous for the *28/*28 genotype and thus cancer patients carrying this variant exhibit irinotecan related toxicity and would require lower doses of irinotecan than patients carrying the 6 TA repeat (*1 allele). The clinical significance of the rare 5 and 8 TA repeats, termed *36 and *37 allele, respectively, in predicting irinotecan toxicities is not well established.
Reflex Testing
An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.
Synonyms
Irenotecan
UGT1A1
UGT 1A1
Sample Type
EDTA whole blood
Collect
Lavender top
Amount to Collect
3 mL
Preferred Volume
3 mL
Minimum Volume
1 mL
Remarks
Avoid hemolysis. Due to stability issues these samples should only be collected at UCSF Monday through noon Friday.
Do not collect sample in heparin. Keep sample refrigerated for overnight or longer storage.
Stability (from collection to initiation)
Refrigerated, 1 month.
Unacceptable Conditions
Insufficient sample received.
Rejection Criteria
Insufficient sample received. Serum, citrated or heparinized plasma received. Samples > 5 days old when received
Test Code
UGT1A1
Performing Lab
Medical Genomics - Molecular Diagnostics
Specimen Preparation
Do not freeze blood. Refrigerate sample if storage is required.
Ship to China Basin Molecular Diagnostics
Preferred Volume
3 mL
Minimum Volume
1 mL
Unacceptable Conditions
Insufficient sample received.
Rejection Criteria
Insufficient sample received. Serum, citrated or heparinized plasma received. Samples > 5 days old when received
Stability (from collection to initiation)
Refrigerated, 1 month.
Reference Interval
Wildtype *1/*1
Most common normal allele is 6 repeats (= *1)
Additional Information
Irinotecan is used for the treatment of metastatic carcinoma of the colon or rectum. It causes severe neutropenia and diarrhea in 20-35% of patients undergoing chemotherapy. The ability to predict toxicity in treated patients is an important consideration.
UGT1A1 catalyzes the inactivation of SN-38, the active and toxic metabolite of irinotecan. The 7TA repeat length polymorphism (termed *28 allele) in the UGT1A1 promoter is associated with decreased UGT1A1 gene expression levels, resulting in lower than normal UGT1A1 enzymatic activity and accumulation of SN-38, the active irinotecan metabolite.
About 15% of North Americans are homozygous for the *28/*28 genotype and thus cancer patients carrying this variant exhibit irinotecan related toxicity and would require lower doses of irinotecan than patients carrying the 6 TA repeat (*1 allele). The clinical significance of the rare 5 and 8 TA repeats, termed *36 and *37 allele, respectively, in predicting irinotecan toxicities is not well established.
CPT Codes
81350
LDT or Modified FDA
Yes
LOINC Codes
51951-2
Available Stat
No
Test Code
UGT1A1
Performing Lab
Medical Genomics - Molecular Diagnostics
Performed
Batched assay performed once every 2 weeks
Methodology
PCR and Fragment analysis
Remarks
Avoid hemolysis. Due to stability issues these samples should only be collected at UCSF Monday through noon Friday.
Do not collect sample in heparin. Keep sample refrigerated for overnight or longer storage.
Collect
Lavender top
Amount to Collect
3 mL
Sample Type
EDTA whole blood
Preferred Volume
3 mL
Minimum Volume
1 mL
Rejection Criteria
Insufficient sample received. Serum, citrated or heparinized plasma received. Samples > 5 days old when received
Unacceptable Conditions
Insufficient sample received.
Specimen Preparation
Do not freeze blood. Refrigerate sample if storage is required.
Ship to China Basin Molecular Diagnostics
Reference Interval
Wildtype *1/*1
Most common normal allele is 6 repeats (= *1)
Synonyms
Irenotecan
UGT1A1
UGT 1A1
Stability (from collection to initiation)
Refrigerated, 1 month.
Reported
10-14 days
Reflex Testing
An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.
Additional Information
Irinotecan is used for the treatment of metastatic carcinoma of the colon or rectum. It causes severe neutropenia and diarrhea in 20-35% of patients undergoing chemotherapy. The ability to predict toxicity in treated patients is an important consideration.
UGT1A1 catalyzes the inactivation of SN-38, the active and toxic metabolite of irinotecan. The 7TA repeat length polymorphism (termed *28 allele) in the UGT1A1 promoter is associated with decreased UGT1A1 gene expression levels, resulting in lower than normal UGT1A1 enzymatic activity and accumulation of SN-38, the active irinotecan metabolite.
About 15% of North Americans are homozygous for the *28/*28 genotype and thus cancer patients carrying this variant exhibit irinotecan related toxicity and would require lower doses of irinotecan than patients carrying the 6 TA repeat (*1 allele). The clinical significance of the rare 5 and 8 TA repeats, termed *36 and *37 allele, respectively, in predicting irinotecan toxicities is not well established.
CPT Codes
81350
LDT or Modified FDA
Yes
LOINC Codes
51951-2
Ordering
Available Stat
No
Performing Lab
Medical Genomics - Molecular Diagnostics
Performed
Batched assay performed once every 2 weeks
Methodology
PCR and Fragment analysis
Reported
10-14 days
Additional Information
Irinotecan is used for the treatment of metastatic carcinoma of the colon or rectum. It causes severe neutropenia and diarrhea in 20-35% of patients undergoing chemotherapy. The ability to predict toxicity in treated patients is an important consideration.
UGT1A1 catalyzes the inactivation of SN-38, the active and toxic metabolite of irinotecan. The 7TA repeat length polymorphism (termed *28 allele) in the UGT1A1 promoter is associated with decreased UGT1A1 gene expression levels, resulting in lower than normal UGT1A1 enzymatic activity and accumulation of SN-38, the active irinotecan metabolite.
About 15% of North Americans are homozygous for the *28/*28 genotype and thus cancer patients carrying this variant exhibit irinotecan related toxicity and would require lower doses of irinotecan than patients carrying the 6 TA repeat (*1 allele). The clinical significance of the rare 5 and 8 TA repeats, termed *36 and *37 allele, respectively, in predicting irinotecan toxicities is not well established.
Reflex Testing
An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.
Synonyms
Irenotecan
UGT1A1
UGT 1A1
Collection
Sample Type
EDTA whole blood
Collect
Lavender top
Amount to Collect
3 mL
Preferred Volume
3 mL
Minimum Volume
1 mL
Remarks
Avoid hemolysis. Due to stability issues these samples should only be collected at UCSF Monday through noon Friday.
Do not collect sample in heparin. Keep sample refrigerated for overnight or longer storage.
Stability (from collection to initiation)
Refrigerated, 1 month.
Unacceptable Conditions
Insufficient sample received.
Rejection Criteria
Insufficient sample received. Serum, citrated or heparinized plasma received. Samples > 5 days old when received
Processing
Test Code
UGT1A1
Performing Lab
Medical Genomics - Molecular Diagnostics
Specimen Preparation
Do not freeze blood. Refrigerate sample if storage is required.
Ship to China Basin Molecular Diagnostics
Preferred Volume
3 mL
Minimum Volume
1 mL
Unacceptable Conditions
Insufficient sample received.
Rejection Criteria
Insufficient sample received. Serum, citrated or heparinized plasma received. Samples > 5 days old when received
Stability (from collection to initiation)
Refrigerated, 1 month.
Result Interpretation
Reference Interval
Wildtype *1/*1
Most common normal allele is 6 repeats (= *1)
Additional Information
Irinotecan is used for the treatment of metastatic carcinoma of the colon or rectum. It causes severe neutropenia and diarrhea in 20-35% of patients undergoing chemotherapy. The ability to predict toxicity in treated patients is an important consideration.
UGT1A1 catalyzes the inactivation of SN-38, the active and toxic metabolite of irinotecan. The 7TA repeat length polymorphism (termed *28 allele) in the UGT1A1 promoter is associated with decreased UGT1A1 gene expression levels, resulting in lower than normal UGT1A1 enzymatic activity and accumulation of SN-38, the active irinotecan metabolite.
About 15% of North Americans are homozygous for the *28/*28 genotype and thus cancer patients carrying this variant exhibit irinotecan related toxicity and would require lower doses of irinotecan than patients carrying the 6 TA repeat (*1 allele). The clinical significance of the rare 5 and 8 TA repeats, termed *36 and *37 allele, respectively, in predicting irinotecan toxicities is not well established.
Administrative
CPT Codes
81350
LDT or Modified FDA
Yes
LOINC Codes
51951-2
Complete View
Available Stat
No
Test Code
UGT1A1
Performing Lab
Medical Genomics - Molecular Diagnostics
Performed
Batched assay performed once every 2 weeks
Methodology
PCR and Fragment analysis
Remarks
Avoid hemolysis. Due to stability issues these samples should only be collected at UCSF Monday through noon Friday.
Do not collect sample in heparin. Keep sample refrigerated for overnight or longer storage.
Collect
Lavender top
Amount to Collect
3 mL
Sample Type
EDTA whole blood
Preferred Volume
3 mL
Minimum Volume
1 mL
Rejection Criteria
Insufficient sample received. Serum, citrated or heparinized plasma received. Samples > 5 days old when received
Unacceptable Conditions
Insufficient sample received.
Specimen Preparation
Do not freeze blood. Refrigerate sample if storage is required.
Ship to China Basin Molecular Diagnostics
Reference Interval
Wildtype *1/*1
Most common normal allele is 6 repeats (= *1)
Synonyms
Irenotecan
UGT1A1
UGT 1A1
Stability (from collection to initiation)
Refrigerated, 1 month.
Reported
10-14 days
Reflex Testing
An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.
Additional Information
Irinotecan is used for the treatment of metastatic carcinoma of the colon or rectum. It causes severe neutropenia and diarrhea in 20-35% of patients undergoing chemotherapy. The ability to predict toxicity in treated patients is an important consideration.
UGT1A1 catalyzes the inactivation of SN-38, the active and toxic metabolite of irinotecan. The 7TA repeat length polymorphism (termed *28 allele) in the UGT1A1 promoter is associated with decreased UGT1A1 gene expression levels, resulting in lower than normal UGT1A1 enzymatic activity and accumulation of SN-38, the active irinotecan metabolite.
About 15% of North Americans are homozygous for the *28/*28 genotype and thus cancer patients carrying this variant exhibit irinotecan related toxicity and would require lower doses of irinotecan than patients carrying the 6 TA repeat (*1 allele). The clinical significance of the rare 5 and 8 TA repeats, termed *36 and *37 allele, respectively, in predicting irinotecan toxicities is not well established.
