APOA5 and agammaglobulinemia: The most frequently reported causes of primary HTG are LPL mutation, apo C-II deficiency, lecithin cholesterol acyl transferase deficiency, apoC-III overexpression, apoAV deficiency, excessive synthesis of angiopoietin-like protein 3, cholesterol ester storage disease, and antibody deficiency against glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 [1,4].