Related Experiment Videos
Late-onset holocarboxylase synthetase deficiency
K M Gibson1, M J Bennett, W L Nyhan
1Institute for Metabolic Disease, Baylor Research Institute, Dallas, Texas, USA.
Journal of Inherited Metabolic Disease
|January 1, 1996
Summary
This study identifies holocarboxylase synthetase deficiency in an older infant, challenging the typical early-onset presentation. This finding expands the differential diagnosis for biotin metabolism defects.
Area of Science:
- Biochemistry
- Genetics
- Pediatrics
Background:
- Multiple carboxylase deficiency (MCD) is a group of inherited metabolic disorders.
- Typically, holocarboxylase synthetase deficiency (HCSD) presents early, while biotinidase deficiency (BTD) presents later.
- Biotin is essential for carboxylase enzymes involved in metabolism.
Purpose of the Study:
- To investigate a suspected biotin utilization abnormality in a 21-month-old patient.
- To determine the specific enzyme deficiency underlying the patient's symptoms.
- To broaden the understanding of HCSD presentation.
Main Methods:
- Analysis of urine organic acid profile.
- In vitro enzyme activity assays.
Main Results:
- Urine organic acids suggested a biotin utilization defect.
- Enzyme studies confirmed holocarboxylase synthetase deficiency (HCSD).
- The patient presented with symptoms typically associated with late-onset MCD.
Conclusions:
- Holocarboxylase synthetase deficiency can present later than previously thought.
- HCSD should be considered in the differential diagnosis of older patients with suspected biotin metabolism defects.
- This case expands the clinical spectrum of HCSD.