What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveObservation

LOINC Code 81258-6: Sample variant allelic frequency

Name: LOINC Code 81258-6: Sample variant allelic frequency
Creator: HealthAssure Clinical Team
Published: 2026-05-21T09:00:05.774Z

81258-6 is a LOINC code used to identify Sample variant allelic frequency in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Sample variant allelic frequency. It is commonly used with the system or sample type ^Patient.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Sample variant allelic frequency. It is commonly used with the system or sample type ^Patient.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Observation

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Sample variant allelic frequency [NFr]

Sample variant allelic frequency

The fraction of all reads in a study sample at a given genomic locus that identify the allele (variant) in question. For homozygotes it will be close to 1.0; for heterozygotes it will be close to 0.5. It can be less than 0.5 in the case of mosaics or multiple chromosome, or mixtures of tumor cells and normal cells. This measure is an attribute of the variant and applies when the method is a Next Generation Sequencing (NGS) or similar. Such methods provide many reads from the sample for each locus. To report population allelic frequency, see [LOINC92821-8]. Allelic frequency is usually reported as a decimal fraction for both Sample Variant Allelic Frequency and Population Allelic Frequency, although it is occasionally reported as a percent. Special care/caution should be taken when reporting and converting to a decimal fraction.

Allelic fraction; Molecular pathology; MOLPATH; Novel allelic frequency; Number fraction; Percent; Point in time; QNT; Quan; Quant; Quantitative; Random; VAF

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Sample variant allelic frequencySample variant allelic frequency [NFr]Sample VAFMOLPATHNFrPt^Patient

Frequently asked questions

Code details

Code81258-6

SystemLOINC

Display nameSample variant allelic frequency

Short nameSample VAF

ComponentSample variant allelic frequency

PropertyNFr

TimingPt

System (specimen)^Patient

ScaleQn

ClassMOLPATH

Example units%

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.56

Last changed2.73

Consumer names

Sample variant allelic frequency

Part names

Sample variant allelic frequencyNFrPt^PatientQnNumber FractionPoint in time (spot)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.