Myers-Skelton Premature Immunosenescence is a systemic genetic disorder with no known cure. The disorder affects the immune system. A congenital disorder, those affected must take medication for their entire lives.
The patients suffering from this condition undergo immunosenescence very early in their lives. Their immune systems age and shutdown prematurely.
During the Ganymede incident, Mao-Kwikowski Mercantile and the United Nations kidnapped several children with this disorder, including Mei Meng, in order to create super soldiers; because these children lacked normal immune systems, a protomolecule infection was more easily controlled.