LOINCActiveBoth

LOINC Code 43723-6: 5,10-Methylenetetrahydrofolate reductase Ql (S)

43723-6 is a LOINC code used to identify 5,10-Methylenetetrahydrofolate reductase Ql (S) 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 5,10-Methylenetetrahydrofolate reductase. It is commonly used with the system or sample type Ser.

Reviewed by HealthAssure Clinical TeamUpdated 25 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 5,10-Methylenetetrahydrofolate reductase. It is commonly used with the system or sample type Ser.

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: Both

What it does not mean

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

Key facts

  • 5,10-Methylenetetrahydrofolate reductase [Presence] in Serum
  • 5,10-Methylenetetrahydrofolate reductase
  • Chemistry; FADH2; Ferredoxin; MTHFR; Ordinal; Point in time; PR; QL; Qual; Qualitative; Random; Screen; Serum; SR

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

5,10-Methylenetetrahydrofolate reductase Ql (S)5,10-Methylenetetrahydrofolate reductase [Presence] in SerumMTHFR Ser Ql5,10-Methylenetetrahydrofolate reductaseCHEM5,10-Methylenetetrahydrofolate reductase, BloodPrThr

Frequently asked questions

Code details

Code43723-6
SystemLOINC
Display name5,10-Methylenetetrahydrofolate reductase Ql (S)
Description5,10-Methylenetetrahydrofolate reductase
Short nameMTHFR Ser Ql
Component5,10-Methylenetetrahydrofolate reductase
PropertyPrThr
TimingPt
System (specimen)Ser
ScaleOrd
ClassCHEM
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.17
Last changed2.73

Consumer names

5,10-Methylenetetrahydrofolate reductase, Blood

Part names

5,10-Methylenetetrahydrofolate reductasePrThrPtSerOrdPresence or ThresholdPoint in time (spot)Serum

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.