https://www.hl7.org/fhir/DSTU2/familymemberhistory.html Family History ID API retrieves the Family History ID that was recorded in the Risk Assessment API. Family Histories are significant health events and conditions for a particular individual related to the subject. This information can be known to different levels of accuracy. Sometimes the exact condition ('asthma') is known, and sometimes it is less precise ('some sort of cancer'). Equally, sometimes the person can be identified ('my aunt Agatha') and sometimes all that is known is that the person was an uncle. NOTE: The number of records returned can be limited and is defaulted to 500.