X-linked severe combined immunodeficiency (X-SCID, or SCID-X1), is an orphan monogenic disorder popularly known as ‘bubble boy disease’ that affects 1 in 50,000-100,000 live births. The most serious of all primary immunodeficiencies, X-SCID causes severe failure of the immune system, including a lack of T cells, natural killer (NK) cells, or functional B cells. For...