substrate accumulation
The buildup of compounds that cannot be properly metabolized due to enzyme deficiencies.
Full Definition
Substrate accumulation occurs when enzyme deficiencies prevent the normal breakdown of specific compounds, leading to their buildup in blood, tissues, or urine. This phenomenon is the basis for many newborn screening tests, as elevated substrate levels can be detected before clinical symptoms appear. For example, phenylalanine accumulates in phenylketonuria due to phenylalanine hydroxylase deficiency. The degree of substrate accumulation often correlates with disease severity and can guide treatment decisions. Understanding accumulation patterns helps differentiate between various metabolic disorders with similar presentations.
Usage
Usage note: Use this term when describing the biochemical basis of screening tests; avoid 'buildup' in formal documentation.
In Context
- "Substrate accumulation was evident in the elevated amino acid profile." — Biochemical genetics report
- "The screening algorithm detects substrate accumulation before toxic levels are reached." — Program methodology description