[Congenital deficiency of metahemoglobin-reductases (diaphorases). A case of cyanosis during general anesthesia].

A case of cyanosis during general anaesthesia in a patient suffering from congenital deficiency of metahaemoglobin-reductase (diaphorase) is reported. The anaesthesiological technique and the probable triggering cause are analysed. The investigation carried out in members of the family to obtain confirmation of the genetic origin of the enzymatic deficiency is also reported.