👉 Bivitellobilharzia is a rare genetic disorder characterized by a single, small cell in the bone marrow that produces a large amount of abnormal blood cells. This condition affects only males and can lead to serious complications such as cancer or organ failure if not treated promptly. It's caused by an imbalance between normal hematopoietic stem cells (HSCs) and abnormal hematopoietic cells, resulting in excessive production of abnormal blood cells.