Adenosine deaminase 2 deficiency

This code represents a rare, autosomal recessive genetic disorder characterized by a deficiency in the enzyme adenosine deaminase 2 (ADA2). The condition typically manifests with systemic inflammation, vasculopathy, immunodeficiency, and hematological abnormalities, often presenting in childhood or early adulthood.

Use this code for patients diagnosed with ADA2 deficiency, confirmed by genetic testing identifying pathogenic variants in the CECR1 gene or by demonstrating reduced ADA2 enzyme activity. This diagnosis is often considered in individuals presenting with recurrent fevers, early-onset strokes, livedo racemosa, or hypogammaglobulinemia.

• Ensure documentation specifies "adenosine deaminase 2" deficiency to differentiate from other ADA deficiencies.
• Consider sequencing this code with manifestations of the disease, such as vasculitis (e.g., M31.8) or stroke (e.g., I63.9).
• Do not confuse with adenosine deaminase (ADA) deficiency (D81.31), which causes severe combined immunodeficiency (SCID).