Maternal cells persist in brains across all ages — SkimNews
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- Sami Kanaan's team at the Fred Hutchinson Cancer Center analyzed brain samples from 37 children (newborns to age 14) removed during epilepsy surgery, comparing their genetic sequences to mouth-swab samples from their mothers using single-nucleus RNA sequencing and a custom tool called Cellector.
- Maternal cells were detected in 26 of the 37 brain samples, averaging 2.2 per 100,000 cells, and were found operating as neurons, microglia, astrocytes, oligodendrocytes, and endothelial cells — not merely sitting dormant.
- Microchimeric cells also showed up in reanalyzed RNA data spanning a 22-week-old fetus to people in their 80s, confirming the phenomenon persists across the lifespan, though numbers decline with age, possibly due to apoptosis.
- Hina Chaudhry at the Icahn School of Medicine at Mount Sinai, who was not involved in the study, called the work "very sophisticated" and said it shows "every human brain is likely a genetic mosaic of more than one person."
- The researchers cautioned that more of the 37 children likely had maternal cells, but the method would have missed cases where mother and child shared identical genetic variants at the markers used.
Why it matters: By pairing a detection tool (Cellector) with paired mother-child brain samples — previously nearly impossible to obtain — the study gives researchers a concrete method and a cell-type map to investigate how lingering maternal cells influence autoimmune risk and tissue repair across a lifetime, rather than treating microchimerism as a curiosity.
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