松村 貴由

Abstract Here we report a patient with holoprosencephaly (HPE) associated with 45, XY,der(18)t(18;21)(p11.2;q21.3),-21 derived from a paternal balanced reciprocal translocation. Array comparative genomic hybridization analysis revealed 18p11.32-p11.21 and 21q11.2-q21.3 deletions. So far, nine cases of monosomy 18p with an unbalanced translocation (18;21) have been reported, four of which presented with HPE. Our case provides a detailed long-term clinical course and helps us to better understand these rare genetic events.

The aging of hematopoietic stem cells (HSCs) substantially alters their characteristics. Mitochondria, essential for cellular metabolism, play a crucial role, and their dysfunction is a hallmark of aging-induced changes. The impact of mitochondrial mass on aged HSCs remains incompletely understood. Here we demonstrate that HSCs with high mitochondrial mass during aging are not merely cells that have accumulated damaged mitochondria and become exhausted. In addition, these HSCs retain a high regenerative capacity and remain in the aging bone marrow. Furthermore, we identified GPR183 as a distinct marker characterizing aged HSCs through single-cell analysis. HSCs marked by GPR183 were also enriched in aged HSCs with high mitochondrial mass, possessing a high capacity of self-renewal. These insights deepen understanding of HSC aging and provide additional perspectives on the assessment of aged HSCs, underscoring the importance of mitochondrial dynamics in aging.