The Adenosine deaminase deficiency results into

Adenosine deaminase (ADA) is an enzyme that converts adenosine and deoxyadenosine into inosine and deoxyinosine, respectively.

When ADA activity is lacking, deoxyadenosine accumulates, especially within developing lymphocytes.

The excess deoxyadenosine is metabolized to toxic nucleotides that damage DNA synthesis and trigger apoptosis of both T‑cells and B‑cells.

This loss of functional lymphocytes severely impairs adaptive immunity, producing a combined severe immunodeficiency.

Clinically, individuals with ADA deficiency experience recurrent infections, failure to thrive, and other signs of immune system failure.

Hence, the primary outcome of Adenosine deaminase deficiency is Dysfunction of the Immune system.