cerating extension for each observation instead of using name -value pattern in Observation resource is creating a bunch of assertions with a value and does not utilise the underlying structure of the observation resource. . The create a dictionary of the dataelements : i.e. For each extension instead create/identifyr a (LOINC)code and define a answer type and value set for the value element. And approach it this way.

Furthermore for nested observations use the .related elements

Example

{ // GenomeBuild // from Element: [extension|http://hl7-fhir.github.io/extensibility.html] "[url|http://hl7-fhir.github.io/extension-geneticsgenomebuild-definitions.html#extension.url]" : "[http://hl7.org/fhir/StructureDefinition/geneticsGenomeBuild]", // *R!* "[valueString|http://hl7-fhir.github.io/extension-geneticsgenomebuild-definitions.html#extension.valueString]" : "<[string|http://hl7-fhir.github.io/datatypes.html#string]>" //Value of extension }

Observation code for GenomeBuild = 1234-5 value type = string

profile for this would be essentially

code *Fixed Value: *{"coding":[

{"system":"[http://loinc.org]","code":"1234-5""display"."GenomeBuild"}

]}

valueString