Meet the Hemifusome

Scientists have recently uncovered a previously unknown organelle inside human cells - the hemifusome. On June 25th, 2025, researchers from the NIH and University of Virginia used an imaging technique called cryo-electron tomography (cryo-ET) to essentially freeze the cells in time, allowing extremely clear images of the organelle to be taken. The discovery of this organelle could potentially open up novel treatments for complex genetic diseases.

Hemifusomes, described as looking somewhat like a snowman, function as a kind of “recycling center”, helping the cell sort, recycle, and discard material. They also play a role in the formation of vesicles, another organelle responsible for the transport of materials. In the bigger picture of cellular material transportation, the hemifusome acts as a transfer center where vesicles connect or relay cargo, revealing a step in the process of material movement that was previously unknown.

Knowledge of how hemifusomes contribute to overall cellular function and health could deepen understanding of how their dysfunction leads to diseases affecting many bodily systems. Hermansky-Pudlak syndrome, for instance, is a rare genetic disorder that can cause albinism, vision problems, lung disease, and issues with blood clotting. Scientists believe that problems with material management in cells are the source of many such disorders. Knowledge of how the hemifusome aids the process of ‘housekeeping’ in cells could lead to specific treatments for genetic diseases caused by this dysfunction.

It’s not everyday that something truly new is discovered inside a cell - and as scientists continue to explore the ins and outs of this new organelle, the understanding of how it fits into the intricate workings of a human cell can provide clarity to a multitude of inherited diseases. Though they have evaded detection until now despite their surprising prevalence in certain areas of cells, the knowledge of the existence of hemifusomes opens up new areas of study of how they act in healthy or unhealthy cells, as well as the development of new treatments for genetic disorders linked to their dysfunction.