https://loinc.org/21666-3 https://loinc.org/21665-5
Hi, we encourage hospitals to adopt gene-related LOINC codes. However, we are having difficulty distinguishing between these two terms in their definitions. Could anyone please help us gain a better understanding?
I also checked the answer from ChatGPT, which is shown below:
1. LOINC 21666-3: EGFR Gene Mutations Tested
Suppose a molecular genetic test report states: “We tested for the following EGFR gene mutations: Exon 19 deletion, L858R, T790M.”
The focus here is on the types of mutations covered by the test, meaning the specific gene mutations that were checked, regardless of whether any mutations were found.
Example: “Tested for Exon 19 deletion, L858R, T790M mutations.”
2. LOINC 21665-5: EGFR Gene Mutations Found
Suppose the test actually found the L858R mutation but did not find any other mutations. In this case, the test report would use this code to specify the actual test result.
Example: “Found L858R mutation.”
Summary
21666-3: Indicates the list of EGFR gene mutations that were tested for, regardless of whether any mutations were found.
21665-5: Indicates the specific EGFR gene mutations that were actually detected in the test.
Hello Li
Welcome to the Forum. Thank you for the question. The “Tested For” series of genes in LOINC are NOT the patient results; they are merely the list of specific mutations looked for. It is a way of clarifying for the clinician that a “No mutations found” did or did not include possibly a familial mutation or a rare mutation. There are 100 LOINC terms of different genes that are in the series “Tested For”.
The “Mutations Found” series ARE the patient results.
In the EGFR example you give, try reading it with 21665-5 EGFR Gene Mutations Found state “No Mutations Found”, yet the 21666-3 EGFR Mutations Tested For list only “Exon 19 deletion, L858R mutations”. Without that list to compare, the clinician wouldn’t be able to recognize that the T790M mutation wasn’t analyzed on the patient.
Does this help? We’re more than happy to assist, and until ChatGPT gets further developed I hope you’ll continue to post questions here in the Forum.
Best regards
Pam
Thank you so much for your quick response and clear explanation. Your confirmation has really helped us feel more confident about our understanding of these codes. I’ve shared your explanation with the relevant officials and also passed it along to the hospital staff. If we have any more questions, we might reach out again. Thanks again for all your help!
