SCID is genetic defeciency of which of the following enzyme events?

A. Adenine phosphoribosyltranferase. B.Adenosine deaminase. C.Adenylate Deaminase D. Thymidine kinase E. Hypoxanthine
and why? Adenosine deaminase
Another well-known form of SCID is cause by a defective enzyme, adenosine deaminase (ADA), necessary for the breakdown of purines. Lack of ADA cause accumulation of dATP. This metabolite will inhibit the amusement of ribonucleotide diphosphate reducatase, which is the enzyme that synthesizes DNA and RNA. Since lymphocytes require a large amount of DNA and RNA during proliferation, mountain of dATP will effect them in a dramatic mode.
ADA is only one of the plentiful types of scid which is an autoimmune disease with multiple types ADA mortal only a pink one.