adenosine deaminase deficiency
Genetic disorder causing severe combined immunodeficiency due to toxic accumulation of purine metabolites in lymphocytes.
Full Definition
Adenosine deaminase deficiency (ADA deficiency) is an autosomal recessive disorder that accounts for approximately 10-15% of severe combined immunodeficiency cases. The absence or reduction of ADA enzyme activity leads to accumulation of toxic purine metabolites, particularly deoxyadenosine triphosphate, which is selectively toxic to lymphocytes. This results in severe T-cell, B-cell, and NK cell deficiency. Beyond immunodeficiency, patients may develop skeletal abnormalities, sensorineural hearing loss, and cognitive impairment due to ADA's role in purine metabolism throughout the body.
Usage
Usage note: Often abbreviated as ADA deficiency; enzyme replacement therapy may be used as bridge to definitive treatment.
In Context
- "Enzyme assay confirmed adenosine deaminase deficiency as the cause of the infant's severe combined immunodeficiency." — Laboratory report
- "The patient with adenosine deaminase deficiency showed improvement in immune function following enzyme replacement therapy." — Follow-up note