Patients with mutations in apo AI (i.e., apo AIMilano and apo AIParis), ABC-A1 (Tangier disease) and LCAT deficiency [50,51,52,53] have very low plasma concentrations of HDL cholesterol, but their CAD risk is often similar or slightly elevated compared to normal subjects [50,51,52,53]. The gene discussed is AOPEP; the disease is Tangier disease.