Home
HelpTest Code LAB958 Biotinidase, Quantitative
Clinical System Name
Biotinidase level
Synonyms
Biotinida
Sample Requirements
Specimen: Whole Blood
Container(s): Dark Green/Sodium Heparin, Lt. Green/Lithium Heparin Microtainer
Preferred Vol:1.0 mL
Minimum Vol: 0.5 mL
Note: Red and gold top tubes are acceptable but not preferred.
Processing Instructions
Reject due to:
Spin: Y
Aliquot: Y
Temp: -20 C
Storage location: Aliquot 0.2 mL plasma and store in CPA Freezer, Biochemical Genetics box
Off-site collection: Spin blood, freeze plasma within 2 hours. Ship sample frozen.
Stability
| Temperature | Time |
|---|---|
| Room temp | ≤2 hrs |
| Refrigerated | ≤2 hrs |
| Frozen | 7 days (-20 C), 1 month (-70 C) |
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | Weekly | 1 week |
Contact the Biochemical Genetics Lab for requests outside of stated availability (206)987-2216.
Department
Department: Biochemical Genetics
Phone: 206-987-2216
CPT Codes
82261
Methodology
Method: Enzymatic/Spectrophotometric
Analytical Volume: 0.2 mL plasma
Limitations: Biotinidase cannot be performed if patient is on a sulfonamide antibiotic.
Reference Range
| Normal (nmol/min/mL) | 5.5 - 17 |
| Partial deficiency | 2.0 - 5.4 |
| Deficient | 0 - 1.9 |
Description
This test is used to diagnose biotinidase deficiency in clinically symptomatic patients and to confirm the diagnosis suspected from abnormal newborn screening.
Clinical Utility
Profound biotinidase deficiency can be characterized by seizures, hypotonia, ataxia, developmental delay, vision problems, hearing loss, and cutaneous abnormalities such as alopecia, skin rash, and candidiasis. Individuals with partial biotinidase deficiency may have hypotonia, skin rash, and hair loss, particularly during times of stress. Once vision problems, hearing loss, and developmental delay occur, they are usually irreversible even with biotin therapy.
Individuals with profound biotinidase deficiency have lower than 10% of mean normal serum biotinidase activity. Individuals with partial biotinidase deficiency have 10-30% of mean normal serum biotinidase activity. Both profound and partial biotinidase deficiency are usually identified by newborn screening.
Children with biotinidase deficiency remain asymptomatic if biotin therapy is instituted early and maintained continuously.
Requisition
Biochemical Genetics Requisition
On the requisition include clinical information needed for appropriate interpretation. (Age, gender, drug therapy and family history)