APOB and hyperinsulinemic hypoglycemia, familial, 4: This is not surprising as heterozygous ABL (specifically one of the parents) were reported with low plasma TC, LDL-C and apoB in other single families [21-23], and the possibility that human MTP deficiency is inherited in a codominant manner had been also suggested in heterozygous of MTP knockout mice with reduced plasma apoB levels [35].