In contrast, it is relatively rare in white individuals from Europe and North America.[23] In Asia, C9 deficiency is quite common among Japanese individuals, with a prevalence of 0.04% to 0.10%; in contrast, the prevalence of C6 deficiency is only 0.0027%.[3,24]. The gene discussed is C9; the disease is hyperinsulinemic hypoglycemia, familial, 4.