Carnosinase deficiency: a new variant with high residual activity
Case seriesHumans
- Design
- Case series
- Subjects
- 1 patient (12-year-old boy) plus parents and 2 siblings
- Dose used in the study
- 100 mg/kg L-carnosine oral load
- What was measured
- Urinary and plasma carnosine after an oral carnosine load, urinary 1-methylhistidine on a high-anserine diet, plasma, liver and sural nerve carnosinase activity, and nerve histology.
What the authors reported
The patient had profound intellectual disability, spastic quadriparesis, optic atrophy and sensory neuropathy with persistent carnosinuria but no carnosinaemia. After a 100 mg/kg load he excreted 28 percent as carnosine versus 1.3 percent in a control. Plasma carnosinase was 0.28 micromol/mL/h (control mean 2.00), liver activity 43 percent and nerve activity 46 percent of control, with axonal degeneration in the nerve. The authors speculate that carnosinuria may be associated with, rather than cause, the neurological findings.
Limits of this study
Single case with a new variant; causation not established. Abstract only.
Source
PubMed 7375183 · doi:10.1203/00006450-198004000-00001
Entry checked against PubMed abstract (E-utilities) on 2026-10-19. The dose shown is the dose the researchers used. It is not a recommendation. How to read this page.