Hyperlipidaemia

 

Primary Hyperlipidaemia:

Frederickson’s classification

 

1. Type I

Lipoprotein lipase deficiency

Defect: mutant or absent LDL, elevated chylomicrons.

Result in failure to metabolize chylomicrone and elevated triglycerides

Present in childhood with:

1. Eruptive xanthomas
2. Lipaemia retinalis
3. Retinal vein thrombosis
4. Pancreatitis
5. Hepatosplenomegaly

      Chylomicrons floating like cream on top of fasting plasma suggest the diagnosis

      Cholesterol normal or ↑, triglyceride↑↑↑↑

      2-type II

Primary hypercholesterolemia

Defect: LDL receptor dysfunction

Typical features:

1. Xanthelasmas
2. Cuneal arcus
3. Tendon xanthomas (Achilles tendon & extensor tendons of the hand)

       IIa elevated LDL, IIb elevated LDL, VLDL.

       Cholesterol ↑↑, triglyceride normal

 

3-type III

Remnant hyperlipidaemia/apo E homozygosity

Defect: mutant apo E, elevated IDL

Additional risk factor leads to accumulation of chylomicrone and VLDL

Plasma cholesterol and triglycerides are elevated

Typical features:

1. CHD
2. PVD
3. Tuberoruptive xanthomas
4. Palmer xanthomas

The xanthomata are triglyceride rich; they are irritant and may redden with scratch marks

Cholesterol↑↑, triglyceride↑↑↑

 

 

                        

 

 

4-type IV

Familial combined Hyperlipidaemia

Both cholesterol and triglycerides are elevated

CHD common

The occurrence of different types of lipidaemia, with absence of peripheral stigmata, suggests the diagnosis.

Elevated VLDL

Cholesterol normal or ↑, triglyceride↑↑

 

 

5-type V

Familial hypertriglyceridaemia

Defect: unkown

Elevated VLDL and chylomicrons.                     

Cholesterol ↑or ↑↑, triglyceride↑↑↑↑