Severe combined immunodeficiency (non-human)

In humans, SCID is colloquially known as "bubble boy" disease, as victims may require complete clinical isolation to prevent lethal infection from environmental microbes.

Similar to the "bubble boy" condition in humans, an affected foal is born with no immune system, and thus generally dies of an opportunistic infection, usually within the first four to six months of life.

Characteristics include a poorly developed thymus gland, decreased T-lymphocytes and IgG, absent IgA, and normal quantities of IgM.

[10] Due to its similarity to X-SCID in humans, breeding colonies of affected dogs have been created in order to study the disease and test treatments, particularly bone marrow transplantation and gene therapy.

It is caused by a loss of DNA protein kinase (DNA-PKcs aka PRKDC), which leads to faulty V(D)J recombination.

As a result, SCID mice have an impaired ability to make T or B lymphocytes, may not activate some components of the complement system, and cannot efficiently fight infections, nor reject tumors and transplants.

[12] In addition to the natural mutation form, SCID in mice can also be created by a targeted knockout of Prkdc.