Environment-sensitive epigenetics and the heritability of complex diseases

Area of Science:

• Genetics
• Epigenetics
• Human Disease

Background:

• Genome-wide association studies (GWAS) have not fully explained the heritability of complex human diseases, a phenomenon known as "missing heritability."
• Previous analyses often overlooked the role of epigenetic variation, despite its association with numerous human diseases.

Purpose of the Study:

• To investigate whether environment-sensitive epigenetic modifications could account for observed familial aggregation patterns in complex diseases.
• To extend existing models of epigenetic inheritance by incorporating environmental influences.

Main Methods:

• Development and application of extended models of epigenetic inheritance.
• Analysis of familial aggregation patterns considering both epigenetic and environmental inheritance.

Main Results:

• Variation in epigenetic and environmental states can lead to highly heritable phenotypes.
• Combined epigenetic and environmental inheritance produced familial covariances greater than purely epigenetic models and comparable to genetic effects.
• Epigenetic variation, inherited directly and via shared environments, significantly contributes to familial aggregation.

Conclusions:

• Epigenetic variation, influenced by environmental factors, is a crucial component of heritability for complex human diseases.
• The findings suggest that epigenetic inheritance, alongside environmental influences, can resolve the "missing heritability" problem.
• This study highlights the importance of considering epigenetic mechanisms in understanding disease etiology and familial aggregation.