WHO/Fredrickson classification of primary hyperlipidaemias
Last reviewed 07/2021
Frederickson Classification of Lipid Disorders
| Type | Average of overnight serum | Elevated particles | Associated clinical disorders | Serum TC | Serum TG |
| I | Creamy top layer | Chylomicrons |
Lipoprotein lipase deficiency, apolipoprotein C-II deficiency
|
N | ++ |
| IIa | Clear | LDL |
Familial hypercholesterolemia, polygenic hypercholesterolemia, nephrosis, hypothyroidism, familial combined hyperlipidemia
|
++ | N |
| IIb | Clear | LDL, VLDL |
Familial combined hyperlipidemia
|
++ | + |
| III | Turbid | IDL |
Dysbetalipoproteinemia
|
+ | + |
| IV | Turbid | VLDL |
Familial hypertriglyceridemia, familial combined hyperlipidemia, sporadic hypertriglyceridemia, diabetes
|
N+ | ++ |
| V | Creamy top, turbid bottom | Chylomicrons, VLDL | Diabetes | + | ++ |
Note that the WHO classification is simply a biochemical phenotypic classification based on which lipoprotein is raised. Also the classification was devised before the importance of HDL as a prognostic indicator was recognised.
* IDL = intermediate-density lipoproteins; LDL = low-density lipoproteins; TC = total cholesterol; TG = triglycerides; VLDL = very low-density lipoproteins;
+ = increased; ++ = greatly increased; N= normal; N+ = normal or increased