These Regulations amend Schedule 4 to the National Health Service Commissioning Board and Clinical Commissioning Groups (Responsibilities and Standing Rules) Regulations 2012 (S.I. 2012/2996) (“the principal Regulations”). Schedule 4 to the principal Regulations specifies services for rare and very rare conditions which the National Health Service Commissioning Board (“the Board”) must arrange for the provision of, as part of the health service.