PROS1 and hyperinsulinemic hypoglycemia, familial, 4: In acutely ill patients, the incidence of protein S deficiency was 67% (33/49) and of protein C deficiency 25% (12/49), while at the followup visit the incidences were 54% (14/26) and 8% (2/26), respectively, [25] which still above the national average of protein C and S deficiency.