Very rare. Abnormality of the hemoglobin due to the replacement of asparagine by threonine in position 102 on the β chain of hemoglobin. This mutation causes a decreased affinity of hemoglobin for O2 (deviation to the right of the curve of dissociation of HbO2): the P50 is 70 mmHg (the normal Hb P50 is 27 mmHg), resulting in a better supply of O2 to tissue and clinical cyanosis. 

Implications anesthésiques: 

low saturation in O2 responding poorly to O2 supplementation; monitoring of paO2 by transcutaneous paO2 or arterial blood gases

References : 

-         Varnado-Rhodes YS.
Clinical cyanosis in a patient presenting for outpatient colonoscopy: a case report of hemoglobin Kansas.
A&A Practice 2019; 12: 433-5

Updated: July 2019