Biotinidase, Serum
Use
Biotinidase deficiency is an autosomal recessive disorder caused by disease-causing variants in the BTD gene. It manifests within the first decade of life with symptoms such as seizures, ataxia, developmental delay, hypotonia, sensorineural hearing loss, vision problems, skin rash, and alopecia. This test is preferred for diagnosing biotinidase deficiency and is also useful for ruling out certain organic acidurias with similar presentations. It is included in newborn screening programs to enable early identification and treatment to prevent clinical features associated with this deficiency.
Special Instructions
Molecular testing via BTD Gene Sequencing with Deletion/Duplication is available if needed. For biotin concentration measurement, order BIOTN / Biotin, Serum. Informed consent is required for New York clients, and must be documented on the order form.
Limitations
A diet high in biotin may result in a normal clinical presentation even with low biotinidase levels, potentially leading to diagnostic confusion. Specimens collected from patients on sulfa drugs may experience assay interference. Genotype-phenotype correlations are not well established; however, certain genetic variants may be linked to profound or partial biotinidase deficiency.
New York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 1982-8
- 1982-8
- 59462-2
- 18771-6
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Plastic vial
Collection Instructions
Centrifuge and aliquot serum into a plastic vial.
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 5 days |
| Frozen | 21 days |