74860-8
LaboratoryERBB2 gene copy number/nucleus in Tissue by FISH
Definition
The average number of fluorescent signals targeting the ERBB2 gene (HER2 locus) in nuclei are determined in order to calculate the average ratio of ERBB2 gene to Chromosome 17 copy number [LOINC: 49683-6]. This term is based on, but not limited in use to, the PathVysion HER-2 DNA Probe Kit, which detects amplification of the ERBB2 gene via fluorescence in situ hybridization (FISH) in formalin-fixed, paraffin-embedded human breast and gastric cancer tissue specimens. The kit contains two probes: one specific to the HER-2/neu gene locus (ERBB2 gene, 17q11.2-q12) and another targeting the alpha satellite DNA sequence at the centromeric region of chromosome 17 (17p11.1-q11.1), called CEP17 (Chromosome Enumeration Probe 17). The average number of HER2 signals along with CEP17 signals [LOINC: 74861-6] are determined by microscopic examination within the same set of nuclei. The specimen is positive for ERBB2 gene amplification if the mean ratio of HER2 to CEP17 signals per nucleus is greater than or equal to 2.00.
LOINC 6-Axis Classification
Component
ERBB2 gene copy number/nucleus
Property
EntNum
Time Aspect
Pt
System
Tiss
Scale Type
Qn
Method Type
FISH
Details
Class
MOLPATH
Order/Observation
Observation
Short Name
ERBB2 copy num/nucleus EntNum Tiss FISH
Display Name
ERBB2 copy number/nucleus FISH (Tiss) [Entitic number]
Related Names
Frequently Asked Questions
What is LOINC code 74860-8?
LOINC code 74860-8 identifies "ERBB2 gene copy number/nucleus in Tissue by FISH". The average number of fluorescent signals targeting the ERBB2 gene (HER2 locus) in nuclei are determined in order to calculate the average ratio of ERBB2 gene to Chromosome 17 copy number [LOINC: 49683-6]. This term is based on, but not limited in use to, the PathVysion HER-2 DNA Probe Kit, which detects amplification of the ERBB2 gene via fluorescence in situ hybridization (FISH) in formalin-fixed, paraffin-embedded human breast and gastric cancer tissue specimens. The kit contains two probes: one specific to the HER-2/neu gene locus (ERBB2 gene, 17q11.2-q12) and another targeting the alpha satellite DNA sequence at the centromeric region of chromosome 17 (17p11.1-q11.1), called CEP17 (Chromosome Enumeration Probe 17). The average number of HER2 signals along with CEP17 signals [LOINC: 74861-6] are determined by microscopic examination within the same set of nuclei. The specimen is positive for ERBB2 gene amplification if the mean ratio of HER2 to CEP17 signals per nucleus is greater than or equal to 2.00.
What does 74860-8 measure?
This code measures ERBB2 gene copy number/nucleus in Tiss. It belongs to the MOLPATH class in the LOINC classification.
What is LOINC?
LOINC (Logical Observation Identifiers Names and Codes) is a universal standard for identifying laboratory and clinical observations. It is maintained by the Regenstrief Institute and used worldwide for health data exchange.