Order Code BTDZ Biotinidase Deficiency, BTD Full Gene Analysis, Varies
Useful For
Second-tier test for confirming biotinidase deficiency (indicated by biochemical testing or newborn screening)
Carrier testing of individuals with a family history of biotinidase deficiency, but disease-causing mutations have not been identified in an affected individual
Testing Algorithm
Amplification and DNA sequencing are utilized to test for the presence of a mutation in the BTD gene.
Special Instructions
Method Name
Polymerase Chain Reaction (PCR) Amplification/DNA Sequencing
Reporting Name
BTD Gene, Full Gene AnalysisSpecimen Type
VariesShipping Instructions
Specimen preferred to arrive within 96 hours of draw.
Specimen Required
Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.
Specimen Type: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA) or yellow top (ACD)
Acceptable: Any anticoagulant
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send specimen in original tube.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Varies | Ambient (preferred) | |
Frozen | ||
Refrigerated |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
An interpretive report will be provided.
Method Description
Bi-directional sequence analysis is performed to test for the presence of a mutation in all coding regions and intron/exon boundaries of the BTD gene.(Unpublished Mayo method)
Day(s) Performed
Varies
Performing Laboratory

CPT Code Information
81404-BTD (biotinidase) (eg, biotinidase deficiency), full gene sequence
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. Molecular Genetics: Biochemical Disorders Patient Information (T527) in Special Instructions
3. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.