Gene expression - PRDM8 reveals aberrant DNA methylation in aging syndromes and is relevant for hematopoietic and neuronal differentiation.

Dyskeratosis congenita (DKC) and idiopathic aplastic anemia (AA) are bone marrow failure syndromes that share characteristics of premature aging with severe telomere attrition. In this study, we analyzed blood samples of 62 AA and 13 DKC patients to demonstrate that their epigenetic age predictions are overall increased, albeit not directly correlated with telomere length. Aberrant DNA methylation was observed in the gene PRDM8 in DKC and AA as well as in other diseases with premature aging phenotype, such as Down syndrome, Werner syndrome and Hutchinson-Gilford-Progeria syndrome. To gain further insight into the functional relevance of PRDM8 we generated induced pluripotent stem cells (iPSCs) with heterozygous and homozygous knockout. Loss of PRDM8 impaired hematopoietic and neuronal differentiation of iPSCs, but it did not impact on epigenetic age. Taken together, aberrant DNA methylation in PRDM8 provides a biomarker for bone marrow failure syndromes, which may contribute to the hematopoietic and neuronal phenotypes of premature aging syndromes. RNA from iPSC-derived neuronal cells was isolated after 27 days of neural differentiation and sequenced on a HiSeq2500 sequencer.