Testing of a person (the person tested) for the detection of a single gene variant for diagnostic purposes, if: the person tested has a biological sibling (the sibling) with a known monogenic condition; and a service described in item 73358, 73359 or 73360 has identified the causative variant for the sibling’s condition; and the results of the testing performed for the sibling are made available for the purpose of providing the detection for the person tested; and the detection is: requested by a consultant physician practising as a clinical geneticist; or requested by a consultant physician practising as a specialist paediatrician, following consultation with a clinical geneticist; and the detection is not performed in conjunction with a service to which item 73362 or 73363 applies Applicable only once per variant per lifetime