# Pre-submission guidance on cfDNA fetal-antigen and carrier-result modeling **URL:** \ **Category:** General\ **Created:** [June 15, 2026, 11:45pm UTC](https://forum.loinc.org/t/pre-submission-guidance-on-cfdna-fetal-antigen-and-carrier-result-modeling/3086 "2026-06-15T23:45:52Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![bcolemanbto](https://forum.loinc.org/letter_avatar_proxy/v4/letter/b/919ad9/32.png) [@bcolemanbto](https://forum.loinc.org/u/bcolemanbto)\ **Post date:** [June 15, 2026, 11:45pm UTC](https://forum.loinc.org/t/pre-submission-guidance-on-cfdna-fetal-antigen-and-carrier-result-modeling/3086/1 "2026-06-15T23:45:52Z")
Hi LOINC team, I’m preparing a coordinated LOINC submission for structured results from our carrier screening, cfDNA NIPT, and fetal antigen testing, and would appreciate brief pre-submission guidance on a few modeling questions before we submit the batch formally. We reviewed 98 result codes and sorted them into three groups: - 31 appear to map cleanly to existing LOINC codes, included for context only; no new requests planned for these. - 9 have candidate existing codes, but we’re not confident the existing terms fully represent our reported result values. - 58 appear to require new or revised terms, primarily for fetal antigen NIPT, single-gene NIPT, and carrier-result interpretations. We’d especially value your guidance on three issues: **1. Modeling novel cfDNA fetal-antigen results** Our fetal antigen results are predicted from maternal plasma cell-free DNA. We’re currently modeling them after LOINC **100670-9** : a gene-allele Component with a `Plas.cfDNA^Fetus` construction, reported as presence/threshold with ordinal values such as **Detected / Not Detected** , rather than as a serologic fetal red-cell antigen construction. Does that approach seem appropriate for the broader fetal antigen panel, including **RHCE, KEL, Duffy, Kidd, MNS, and HPA platelet antigens**? Or would LOINC prefer these modeled as fetal red-cell or platelet antigen phenotype terms instead? **2. Carrier-screen result interpretations** Most of our carrier results are reported to providers as a collapsed **NEGATIVE / POSITIVE** interpretation. The closest existing terms we found are gene mutation-analysis terms with identity, document, or method-specific constructions. For example, some interpretive carrier terms include a specific method such as **MS.MALDI-TOF** — e.g., **77017-2** — whereas our result is a method-agnostic molecular carrier interpretation. For **NEGATIVE / POSITIVE** carrier interpretations by molecular genetics, would LOINC prefer that we reuse existing interpretive terms where available, request changes to existing terms, or submit new method-agnostic interpretive terms? This affects approximately 13 of our result codes. **3. Candidate terms with incomplete answer-value coverage** For several results, a candidate code is close but may not cover all reported values. For example, our **22q11.2** result reports **Low Risk / High Risk** and maternal findings such as **maternal\_duplication** and **maternal\_deletion**. The existing fetal 22q11.2 deletion risk term, **88572-3** , appears to cover the fetal risk interpretation but not necessarily the maternal findings. For cases like this, would you advise using the existing code with local answer values, requesting a new distinct observation, or submitting a change request / revised term? Happy to share our full crosswalk, including all three buckets with candidate codes, proposed names, and rationale, on request. Thank you for any guidance before we submit. We’re aiming to keep the formal submission as clean and easy to review as possible. ---
**Author:** ![pitk0006](https://forum.loinc.org/letter_avatar_proxy/v4/letter/p/c89c15/32.png) [@pitk0006](https://forum.loinc.org/u/pitk0006)\ **Post date:** [June 16, 2026, 9:49pm UTC](https://forum.loinc.org/t/pre-submission-guidance-on-cfdna-fetal-antigen-and-carrier-result-modeling/3086/2 "2026-06-16T21:49:30Z")
Sounds like these are questions for the LOINC team. ---
**Author:** ![bcolemanbto](https://forum.loinc.org/letter_avatar_proxy/v4/letter/b/919ad9/32.png) [@bcolemanbto](https://forum.loinc.org/u/bcolemanbto)\ **Post date:** [June 16, 2026, 10:22pm UTC](https://forum.loinc.org/t/pre-submission-guidance-on-cfdna-fetal-antigen-and-carrier-result-modeling/3086/3 "2026-06-16T22:22:25Z")
Thanks, Andrea and understood. Is there a preferred channel for sending these questions to the right team? ---
**Author:** ![ehafeza](https://forum.loinc.org/letter_avatar_proxy/v4/letter/e/43a26b/32.png) [@ehafeza](https://forum.loinc.org/u/ehafeza)\ **Post date:** [June 16, 2026, 10:58pm UTC](https://forum.loinc.org/t/pre-submission-guidance-on-cfdna-fetal-antigen-and-carrier-result-modeling/3086/4 "2026-06-16T22:58:47Z")
Hi Brian, We appreciate your request for guidance on submissions. Your timing is impeccable, because we are opening the conversation around cfDNA internally, and are looking into defining rules or heuristics to approach modeling such concepts in LOINC, as well as revisiting the rules created to algorithmically generate naming. We have gathered the needed information to tackle this subject and we are just a couple of weeks from meeting internally to decide on the appropriate way to model such concepts. Having said that I will take your request on this forum, and add it to our internal research done for our future internal modeling call. Once we get the result, I or anyone on our team will gladly reconnect and help you in the steps to fill the submission form based on the criteria you provided, or if there are changes, we can also communicate. We will circle back in few weeks(mid to end of July ). Thank you very much Eza ---
**Author:** ![bcolemanbto](https://forum.loinc.org/letter_avatar_proxy/v4/letter/b/919ad9/32.png) [@bcolemanbto](https://forum.loinc.org/u/bcolemanbto)\ **Post date:** [June 16, 2026, 11:33pm UTC](https://forum.loinc.org/t/pre-submission-guidance-on-cfdna-fetal-antigen-and-carrier-result-modeling/3086/5 "2026-06-16T23:33:33Z")
Thank you very much — this is extremely helpful, and the timing is great on our side as well! I’ll hold off on finalizing the cfDNA-related submission details until your team has had the internal modeling discussion. In the meantime, I’ll also keep our crosswalk organized into existing-code matches, guidance-needed candidates, and proposed new terms, with the reported answer values and proposed six-part constructions documented for each. Please let me know if it would be useful for me to share the crosswalk or a few representative examples ahead of your internal call. Otherwise, we’ll wait to hear back from the team in July. Thanks again! ---
**Author:** ![ehafeza](https://forum.loinc.org/letter_avatar_proxy/v4/letter/e/43a26b/32.png) [@ehafeza](https://forum.loinc.org/u/ehafeza)\ **Post date:** [June 17, 2026, 1:17am UTC](https://forum.loinc.org/t/pre-submission-guidance-on-cfdna-fetal-antigen-and-carrier-result-modeling/3086/6 "2026-06-17T01:17:54Z")
Hi Brian, please share any additional information if you have available and of course you can. It is valuable to consider Thank you much Eza ---
**Author:** ![pitk0006](https://forum.loinc.org/letter_avatar_proxy/v4/letter/p/c89c15/32.png) [@pitk0006](https://forum.loinc.org/u/pitk0006)\ **Post date:** [June 17, 2026, 3:37pm UTC](https://forum.loinc.org/t/pre-submission-guidance-on-cfdna-fetal-antigen-and-carrier-result-modeling/3086/8 "2026-06-17T15:37:10Z")
Thanks @ehafeza for addressing. @bcolemanbto The LOINC team can be contacted directly at [content@loinc.org](mailto:content@loinc.org) I’ll defer to Eza responses on this topic too. ---
**Author:** ![ehafeza](https://forum.loinc.org/letter_avatar_proxy/v4/letter/e/43a26b/32.png) [@ehafeza](https://forum.loinc.org/u/ehafeza)\ **Post date:** [June 22, 2026, 3:12am UTC](https://forum.loinc.org/t/pre-submission-guidance-on-cfdna-fetal-antigen-and-carrier-result-modeling/3086/9 "2026-06-22T03:12:27Z")
Thank you Brian, the additional information will be very helpful. I will get back to you once we are clear on the next steps. Eza ---
**Author:** ![bcolemanbto](https://forum.loinc.org/letter_avatar_proxy/v4/letter/b/919ad9/32.png) [@bcolemanbto](https://forum.loinc.org/u/bcolemanbto)\ **Post date:** [June 22, 2026, 7:17pm UTC](https://forum.loinc.org/t/pre-submission-guidance-on-cfdna-fetal-antigen-and-carrier-result-modeling/3086/10 "2026-06-22T19:17:18Z")
Thank you Eza! I have emailed my crosswalk sheet with the subject line: “LOINC: Pre-submission guidance on cfDNA fetal-antigen and carrier-result modeling”