Rocky mountain spotted fever and deficiency in glucose-6-phosphate dehydrogenase

Deficiency in glucose-6-phosphate dehydrogenase (G6PD) is a sex-linked recessive condition found principally in American black males, of whom 12% are affected. Likewise, the death rate for Rocky Mountain spotted fever (RMSF) is disproportionately high in black males. Twenty-two male patients with documented RMSF were classified as to G6PD type on the basis of activity and electrophoretic mobility of the enzyme. Severe RMSF was defined by death, acute renal failure, coma, seizures, multifocal neurologic signs, or severe coagulopathy. A binomial expansion revealed that among seven black males with severe RMSF, an overrepresentation of G6PD deficiency (three cases) was found at the P = 0.042 level of significance (figure). Clinical specimens from 15 white males with RMSF served as enzyme controls. Two fatal cases of RNSF with G6PD deficiency were fulminant.