Type 5 hyperlipidaemia

By using lipoprotein electrophoresis (LPEP) and ultracentrifugation, Fredrickson, Levy, and Lees (FLL) separated clinical dyslipidaemia into five phenotypes (types I–V) of hyperlipoproteinemia (HLP), each phenotype representing a characteristic abnormality of specific lipoproteins. (1)

Type 5 hyperlipidaemia has a prevalence of 0.13-0.15% in the adult population. (2)

Features include: (3)

• normal or slightly raised plasma cholesterol
• raised triglyceride (chylomicrons and VLDL)
• lipoprotein lipase or apo-CII deficiency
• clinical features may include:
  • eruptive xanthoma - these are characteristic of severe hypertriglyceridemia - yellow papules on the extensor surfaces of back, arms, buttocks and legs
  • hepatosplenomegaly may occur
  • lipaemia retinalis may occur - retinal arteries and veins appearing white on fundoscopy

Note - moderate to severe hypertriglyceridemia also leads to an increased risk of pancreatitis (4)

Reference

1. Fredrickson D.S., Levy R.I., Lees R.S. Fat transport in lipoproteins--an integrated approach to mechanisms and disorders. N. Engl. J. Med. 1967;276:215–225. doi: 10.1056/NEJM196701262760406.
2. Sathiyakumar V et al. Modern prevalence of the Fredrickson-Levy-Lees dyslipidemias: Findings from the Very Large Database of Lipids and National Health and Nutrition Examination Survey. Arch. Med. Sci. 2019;16:1279–1287
3. Sniderman A., Couture P., de Graaf J. Diagnosis and treatment of apolipoprotein B dyslipoproteinemias. Nat. Rev. Endocrinol. 2010;6:335–346.
4. Virani S.S et al. 2021 ACC Expert Consensus Decision Pathway on the Management of ASCVD Risk Reduction in Patients with Persistent Hypertriglyceridemia: A Report of the American College of Cardiology Solution Set Oversight Committee. J. Am. Coll. Cardiol. 2021;78:960–993.