Levels of select PCB and PBDE congeners in human postmortem brain reveal possible environmental involvement in 15q11-q13 duplication autism spectrum disorder.

Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) and polybrominated diphenylethers (PBDEs) that bioaccumulate in lipid-rich tissues are of concern as developmental neurotoxicants. Epigenetic mechanisms such as DNA methylation act at the interface of genetic and environmental factors implicated in autism-spectrum disorders. The relationship between POP levels and DNA methylation patterns in individuals with and without neurodevelopmental disorders has not been previously investigated.

Epigenetic investigation of variably X chromosome inactivated genes in monozygotic female twins discordant for primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is an autoimmune chronic cholestatic liver disease with a strong genetic susceptibility due to the high concordance in monozygotic (MZ) twins and a striking female predominance. Women with PBC manifest an enhanced X monosomy rate in peripheral lymphocytes and we thus hypothesized an X chromosome epigenetic component to explain PBC female prevalence. While most genes on the female inactive X chromosome are silenced by promoter methylation following X chromosome inactivation (XCI), approximately 10% of X- linked genes exhibit variable escape from XCI in healthy females.