Common and rare gene variants affecting plasma LDL cholesterol

Area of Science:

• Genetics
• Cardiovascular Medicine
• Biochemistry

Background:

• Plasma low-density lipoprotein (LDL) cholesterol is a critical health indicator with complex genetic underpinnings.
• LDL receptor (LDLR) activity in the liver is a primary determinant of LDL cholesterol levels.
• Inherited disorders like familial hypercholesterolaemia (FH) result from mutations affecting LDLR function or its regulatory proteins.

Purpose of the Study:

• To explore the genetic basis of plasma LDL cholesterol levels.
• To identify genes and variants associated with both high and low LDL cholesterol phenotypes.
• To understand the clinical significance of genetic variations in cholesterol metabolism.

Main Methods:

• Analysis of genetic mutations in genes related to LDL cholesterol metabolism, including LDLR, APOB, PCSK9, NPC1L1, and MTP.
• Examination of the association between specific gene variants (gain-of-function and loss-of-function) and plasma LDL cholesterol levels.
• Review of clinical phenotypes associated with these genetic variations, such as FH and familial hypobetalipoproteinaemia (FHBL).

Main Results:

• Mutations in LDLR, APOB, and PCSK9 are linked to familial hypercholesterolaemia.
• Loss-of-function mutations in PCSK9 are associated with low LDL cholesterol and may offer protection against coronary heart disease.
• Variations in NPC1L1 and APOE have more modest effects on LDL cholesterol levels compared to PCSK9 variants.

Conclusions:

• Heritable variation in plasma LDL cholesterol is influenced by sequence variations across multiple genes.
• Both common and rare gene variants contribute to the spectrum of LDL cholesterol phenotypes.
• Understanding these genetic factors is crucial for diagnosing and managing dyslipidaemia and cardiovascular risk.