Multiple Specimen Testing

first demo.json

[
    {
        "resourceType": "Specimen",
        "id": "tumor",
        "type": {
            "coding": [
                {
                    "system": "http://terminology.hl7.org/CodeSystem/v2-0487",
                    "code": "TUMOR",
                    "display": "Tumor"
                }
            ]
        },
        "subject": {
            "reference": "urn:uuid:f7a438e6-f484-453d-97e8-aa4d51008648"
        }
    },
    {
        "resourceType": "Specimen",
        "id": "blood (normal specimen)",
        "type": {
            "coding": [
                {
                    "system": "http://terminology.hl7.org/CodeSystem/v2-0487",
                    "code": "BLD",
                    "display": "Whole blood"
                }
            ]
        },
        "subject": {
            "reference": "urn:uuid:f7a438e6-f484-453d-97e8-aa4d51008648"
        }
    },
    {
        "resourceType": "Observation",
        "meta": {
            "profile": [
                "http://hl7.org/fhir/uv/genomics-reporting/StructureDefinition/variant"
            ]
        },
        "subject": {
            "reference": "urn:uuid:f7a438e6-f484-453d-97e8-aa4d51008648"
        },
        "valueCodeableConcept": {
            "coding": [
                {
                    "system": "http://loinc.org",
                    "code": "LA9633-4",
                    "display": "Present"
                }
            ]
        },
        "specimen": {
            "extension": [
                {
                    "url": "http://hl7.org/fhir/uv/genomics-reporting/StructureDefinition/multi-specimen",
                    "extension": [
                        {
                            "url": "specimen-relation",
                            "valueCodeableConcept": {
                                "coding": [
                                    {
                                        "system": "TBD",
                                        "code": "tumor"
                                    }
                                ]
                            }
                        },
                        {
                            "url": "specimen",
                            "valueReference": {
                                "reference": "Specimen/tumor"
                            }
                        }
                    ]
                },
                {
                    "url": "http://hl7.org/fhir/uv/genomics-reporting/StructureDefinition/multi-specimen",
                    "extension": [
                        {
                            "url": "specimen-relation",
                            "valueCodeableConcept": {
                                "coding": [
                                    {
                                        "system": "TBD",
                                        "code": "normal-tissue"
                                    }
                                ]
                            }
                        },
                        {
                            "url": "specimen",
                            "valueReference": {
                                "reference": "Specimen/blood"
                            }
                        }
                    ]
                }
            ],
            "reference": "Specimen/tumor"
        },
        "component": [
            {
                "code": {
                    "coding": [
                        {
                            "system": "http://loinc.org",
                            "code": "48002-0",
                            "display": "Genomic source class"
                        }
                    ]
                },
                "valueCodeableConcept": {
                    "coding": [
                        {
                            "system": "http://loinc.org",
                            "code": "LA6684-0",
                            "display": "Somatic"
                        }
                    ]
                }
            },
            {
                "code": {
                    "coding": [
                        {
                            "system": "http://loinc.org",
                            "code": "48018-6",
                            "display": "Gene studied [ID]"
                        }
                    ]
                },
                "valueCodeableConcept": {
                    "coding": [
                        {
                            "system": "http://www.genenames.org/geneId",
                            "code": "HGNC:7989",
                            "display": "NRAS"
                        }
                    ]
                }
            }
        ]
    }
]