Bloom syndrome patients and mice display accelerated epigenetic aging

Bloom syndrome (BSyn) is an autosomal recessive disorder caused by variants in the BLM gene, which is involved in genome stability. Patients with BSyn present with poor growth, sun sensitivity, mild immunodeficiency, diabetes, and increased risk of cancer, most commonly leukemias. Interestingly, patients with BSyn do not have other signs of premature aging such as early, progressive hair loss and cataracts. We set out to determine epigenetic age in BSyn, which can be a better predictor of health and disease over chronological age. Our results show for the first time that patients with BSyn have evidence of accelerated epigenetic aging across several measures in blood lymphocytes, as compared to carriers. Additionally, homozygous Blm mice exhibit accelerated methylation age in multiple tissues, including brain, blood, kidney, heart, and skin, according to the brain methylation clock. Overall, we find that Bloom syndrome is associated with accelerated epigenetic aging effects in multiple tissues and more generally a strong effect on CpG methylation levels.

Automated summary

Bloom syndrome (BSyn) is caused by variants in the BLM gene and manifests as poor growth, sun sensitivity, mild immunodeficiency, diabetes, and increased cancer risk, particularly leukemias. Our study reveals accelerated epigenetic aging in BSyn patients compared to carriers, as evidenced by multiple measures in blood lymphocytes. Additionally, homozygous Blm mice exhibit accelerated methylation age in various tissues according to the brain methylation clock. Overall, Bloom syndrome is associated with accelerated epigenetic aging effects in multiple tissues and significant impact on CpG methylation levels.