Characterisation of one or more pathogenic or likely pathogenic germline gene variants, requested by a specialist or consultant physician, if: (a) the patient is a first-degree or second‑degree biological relative of a person with a pathogenic or likely pathogenic germline gene variant that is confirmed by laboratory findings; and (b) the service is performed for the purpose of assessing present or future risk of a cardiac arrhythmia or channelopathy; and (c) a service to which item 73416 applies has not previously been performed for the patient Applicable once per variant per lifetime