SCID stands for severe combined immunodeficiency. It is a type of primary immunodeficiency disease (PID). It is a rare and also at times fatal kind of human immunodeficiency disorder. SCID is often called "bubble boy disease". SCID became widely known during the 1970's and 80's, when the world learned of David Vetter, a boy with X-linked SCID, who lived for 12 years in a plastic, germ-free bubble.[1]
SCID is due to diverse genetic causes which result into deficiency or absence of T-lymphocytes and B-Lymphocytes (also seen in many cases are affected natural killer or NK cells).The humoral parts as well as the cells involved in immune system functioning cannot work properly. So individual can easily fall prey to opportunistic infections.
The most commonly quoted figure for the prevalence of SCID is around 1 in 100,000 births, although this is regarded by some to be an underestimate of the true prevalence; and a figure of about 1 in 65,000 live births has been reported for Australia. Recent studies indicate that one in every 2,500 children in the Navajo population inherit severe combined immunodeficiency. This condition is a significant cause of illness and death among Navajo children. Ongoing research reveals a similar genetic pattern among the related apache people.[2]
