FULMINANT MENINGOCOCCAL SEPTIC SHOCK IN A BOY WITH COMBINED INHERITEDPROPERDIN AND PROTEIN-C DEFICIENCY

A 7-year-old patient with fulminant septic shock due to Neissrria meni ngitidis of the uncommon serogroup Y developed extensive gangrene of t he limbs. Multiple amputations were necessary and a pulmonary embolism occurred within 2 days post-operatively. Complement and haemostatic s ystem studies, done after recovery, showed a complete absence of prope rdin antigen and a low protein C antigen and activity level in plasma. Defective haemolytic activity in gel by the alternative pathway of co mplement activation could be restored with purified properdin, indicat ing a properdin deficiency type 1. Protein C antigen level as well as activity were in agreement with a protein C deficiency type I. The pol ymerase chain reaction (PCR) product of exon five of the protein C gen e showed a substitution of (72)Gly by Arg. Both deficiencies were trac ed among relatives of the patient. Serum of the father of the patient' s mother was also properdin-deficient. Microsatellite haplotyping of t he X-chromosome of the patient and his relatives showed that a distinc t haplotype cosegregated with the properdin deficiency (Lodscore 2.25; four informative meioses). The protein C type I deficiency was presen t in the patient's mother and her mother and cosegregated with the mut ation found. So far as is known, this is the first patient described w ith combined inherited properdin deficiency and protein C deficiency.