primary deficiency
A direct enzyme or protein defect causing the screened disorder, as opposed to secondary causes.
Full Definition
Primary deficiency refers to a direct genetic defect in an enzyme, transporter, or other protein that directly causes the metabolic disorder being screened. This contrasts with secondary deficiencies, where the enzyme or metabolite abnormality results from another underlying condition such as liver disease, medication effects, or nutritional deficiencies. In newborn screening, distinguishing primary from secondary deficiencies is crucial for determining appropriate follow-up care. Primary deficiencies typically require lifelong management and genetic counseling, while secondary deficiencies may resolve with treatment of the underlying cause.
Usage
Usage note: Always specify 'primary' to distinguish from secondary causes; avoid using 'deficiency' alone in ambiguous contexts.
In Context
- "Molecular testing confirmed a primary deficiency rather than a secondary cause of the elevated metabolite." — Diagnostic workup report
- "The genetics team explained that primary deficiency would require ongoing dietary management." — Patient consultation note