A recessively inherited immunodeficiency disorder characterized by a lack of circulating T and Natural Killer Cells and a normal level of B cells. The disorder is caused by a defect on the JAK3 gene. Infants may display symptoms such as pancytopenia, skin rash and abnormal liver function due to a graft-versus-host reaction to the mother's T cells via the placenta. If the condition is not treated, death occurs. See also Severe combined immunodeficiency, T- B+ due to JAK3 deficiency