Haplotype describe a set of genomic variations that appear on a single strand of DNA - and which are therefore typically inherited together. Many haplotypes are expressed as simple strings, and can be conveyed in valueCodeableConcept.text. In some cases, haplotypes are sufficiently standardized to be conveyed as codes in valueCodeableConcept.code.

For Pharmacogenomics, implementers SHOULD send coded haplotypes. Here is an example using PharmVar:

• Coded PGx
  

  {
    "valueCodeableConcept": {
      "coding": [{
        "system": "http://www.pharmvar.org",
        "code": "PV01777",
        "display": "CYP2C9*3.002"
      }]
      "text": "CYP2C9*3B"
    }
  }
          

For both genotypes and haplotypes, reporting the structured variant data is optional. However, implementers SHOULD when possible. For example, sending PGX star-alleles without variant-level information is not best practice as it is both potentially ambiguous and can preclude future utility of the report.

Review the Genotypes page for guidance on reporting genotypes and haplotypes together.