Scoline apnoea: For suxamethonium (scoline) or mivacurium sensitivity: request serum/plasma cholinesterase, a low level of activity could indicate an abnormal phenotype.
Genetic cholinesterase variants may be classified by measuring their sensitivity to inhibitors. This is termed cholinesterase phenotyping.
Genotyping (available on provision of an EDTA whole blood specimen) provides supportive information.