{ "resourceType" : "Observation", "id" : "variant-egfr", "meta" : { "profile" : ["https://fhir.nwgenomics.nhs.uk/StructureDefinition/Variant"] }, "language" : "en", "text" : { "status" : "generated", "div" : "

Generated Narrative: Observation variant-egfr

Profile: Variant (Observation)

identifier: 00c22e97-a226-4845-b17a-e24ec1f4f77a

status: Final

category: Genetics, Laboratory

code: Genetic variant assessment

subject: Theon SHEFFIELD

effective: 2026-07-13 10:37:26+0000

value: Present

note:

ILLUSTRATIVE VALUES ONLY. The allelic frequency component (81258-6) is the field of primary clinical interest for a dPCR ctDNA result: it carries the mutant-allele fraction quantified directly by the assay (droplet/bead-positive fraction, Poisson-corrected), which is what a clinician uses to gauge ctDNA burden and track it serially — analogous to how VAF is used from NGS, but here derived from a targeted few-plex assay rather than sequencing depth.

\n

method: Digital PCR (BEAMing / OncoBEAM platform). NOTE: unlike 'Sequencing' (LOINC LA26398-0), the standard LOINC/SNOMED CT answer lists referenced by this IG do not currently include a dedicated coded answer for 'digital PCR' — captured here as free text pending a suitable coded term (e.g. a local or SNOMED CT extension) being agreed with your terminology team.

component

code: Variant category

value: Sequence Variant

component

code: Gene studied [ID]

value: EGFR

component

code: DNA change (c.HGVS)

value: NM_005228.5:c.2369C>T

component

code: DNA change type

value: substitution

component

code: Genomic source class [Type]

value: Somatic

component

code: Sample variant allelic frequency [NFr]

value: 0.42 % (Details: UCUM code% = '%')

" }, "identifier" : [{ "value" : "00c22e97-a226-4845-b17a-e24ec1f4f77a" }], "status" : "final", "category" : [{ "coding" : [{ "system" : "http://terminology.hl7.org/CodeSystem/v2-0074", "code" : "GE", "display" : "Genetics" }] }, { "coding" : [{ "system" : "http://terminology.hl7.org/CodeSystem/observation-category", "code" : "laboratory" }] }], "code" : { "coding" : [{ "system" : "http://loinc.org", "code" : "69548-6", "display" : "Genetic variant assessment" }] }, "subject" : { "reference" : "urn:uuid:2160525b-0168-4f40-8ebf-9b053052a62c", "display" : "Theon SHEFFIELD" }, "effectiveDateTime" : "2026-07-13T10:37:26+00:00", "valueCodeableConcept" : { "coding" : [{ "system" : "http://loinc.org", "code" : "LA9633-4", "display" : "Present" }] }, "note" : [{ "text" : "ILLUSTRATIVE VALUES ONLY. The allelic frequency component (81258-6) is the field of primary clinical interest for a dPCR ctDNA result: it carries the mutant-allele fraction quantified directly by the assay (droplet/bead-positive fraction, Poisson-corrected), which is what a clinician uses to gauge ctDNA burden and track it serially — analogous to how VAF is used from NGS, but here derived from a targeted few-plex assay rather than sequencing depth." }], "method" : { "text" : "Digital PCR (BEAMing / OncoBEAM platform). NOTE: unlike 'Sequencing' (LOINC LA26398-0), the standard LOINC/SNOMED CT answer lists referenced by this IG do not currently include a dedicated coded answer for 'digital PCR' — captured here as free text pending a suitable coded term (e.g. a local or SNOMED CT extension) being agreed with your terminology team." }, "component" : [{ "code" : { "coding" : [{ "system" : "http://loinc.org", "code" : "83005-9", "display" : "Variant category" }] }, "valueCodeableConcept" : { "coding" : [{ "system" : "https://fhir.nwgenomics.nhs.uk/CodeSystem/IGeneVariantCategory", "code" : "SEQV", "display" : "Sequence Variant" }] } }, { "code" : { "coding" : [{ "system" : "http://loinc.org", "code" : "48018-6", "display" : "Gene studied [ID]" }] }, "valueCodeableConcept" : { "coding" : [{ "system" : "http://www.genenames.org", "code" : "HGNC:3236", "display" : "EGFR" }] } }, { "code" : { "coding" : [{ "system" : "http://loinc.org", "code" : "48004-6", "display" : "DNA change (c.HGVS)" }] }, "valueCodeableConcept" : { "coding" : [{ "system" : "http://varnomen.hgvs.org", "code" : "NM_005228.5:c.2369C>T" }] } }, { "code" : { "coding" : [{ "system" : "http://loinc.org", "code" : "48019-4", "display" : "DNA change type" }] }, "valueCodeableConcept" : { "coding" : [{ "system" : "http://www.sequenceontology.org", "code" : "SO:1000002", "display" : "substitution" }] } }, { "code" : { "coding" : [{ "system" : "http://loinc.org", "code" : "48002-0", "display" : "Genomic source class [Type]" }] }, "valueCodeableConcept" : { "coding" : [{ "system" : "http://loinc.org", "code" : "LA6684-0", "display" : "Somatic" }] } }, { "code" : { "coding" : [{ "system" : "http://loinc.org", "code" : "81258-6", "display" : "Sample variant allelic frequency [NFr]" }] }, "valueQuantity" : { "value" : 0.42, "unit" : "%", "system" : "http://unitsofmeasure.org", "code" : "%" } }] }