African ancestry-derived APOL1 risk genotypes show proximal epigenetic associations

Area of Science:

• Genetics
• Epigenetics
• Nephrology

Background:

• Apolipoprotein L1 (APOL1) G1 and G2 variants are key genetic risk factors for kidney disease in individuals of African ancestry.
• These APOL1 risk variants exhibit recessive inheritance and are thought to cause disease through a toxic gain-of-function mechanism.
• Variability in disease presentation suggests the influence of other genetic or environmental factors, including epigenetic modifications.

Purpose of the Study:

• To investigate the role of DNA methylation in relation to APOL1 risk variants.
• To identify specific CpG sites (CpGs) whose methylation levels are influenced by APOL1 risk alleles.

Main Methods:

• Methylation quantitative trait locus (meQTL) analysis was conducted on DNA from 611 African American individuals.
• Discovery and replication studies were performed to identify significant associations between CpG methylation and APOL1 risk variants.

Main Results:

• Five CpGs were identified with significant associations with APOL1 risk alleles.
• One CpG-APOL1 association remained significant and was independent of other known genomic variants.
• These findings indicate proximal DNA methylation alterations linked to APOL1 risk.

Conclusions:

• The study identified specific DNA methylation changes associated with APOL1 risk variants.
• These epigenetic alterations may contribute to the variable risk and clinical manifestations observed in APOL1-associated diseases.
• Understanding these methylation patterns offers insights into the pathogenesis of APOL1 nephropathy.