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Biotinidase Deficiency (BTD) 5 Mutations
0051700
Ordering Recommendation

Molecular DNA test to confirm a diagnosis of biotinidase (BTD) deficiency when biotinidase enzymatic activity is low. Carrier testing for individuals with a family history of BTD deficiency if familial variants are included in this test. To diagnose or rule out BTD deficiency, refer to Biotinidase, Serum (with Paired Normal Control) (0093362).

Mnemonic
BTD MUT
Methodology
Polymerase Chain Reaction/Capillary Electrophoresis
Performed
Sun-Sat
Reported
7-10 days
New York DOH Approval Status
This test is New York DOH approved.
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
 
Collect
Lavender (EDTA), pink (K2EDTA), or yellow (ACD solution A or B). 
Specimen Preparation
Transport 3 mL whole blood. (Min: 1 mL) 
Storage/Transport Temperature
Refrigerated. 
Unacceptable Conditions
 
Remarks
 
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable 
Reference Interval
Interpretive Data
Background information for Biotinidase Deficiency (BTD) 5 Mutations:
Characteristics: Ataxia, hypotonia, developmental delay, respiratory problems, seizures, vision problems, hearing loss, alopecia, rash, candidiasis, metabolic ketolactic acidosis, organic aciduria and mild hyperammonemia.
Incidence:
1 in 60,000.
Inheritance: Autosomal recessive.
Penetrance: Unknown.
Cause: Deleterious mutations in the BTD gene.
Mutations Tested: c.98_104del7ins3 (G98d7i3), Q456H, R538C, and the double mutation A171T:D444H are severe; D444H alone, is mild.
Clinical Sensitivity & Specificity: 60 and 99 percent, respectively.
Methodology: Polymerase chain reaction followed by single nucleotide extension (SNE) and capillary electrophoresis.
Analytical Sensitivity & Specificity: 99 percent.
Limitations: Mutations other than those targeted in BTD will not be detected; analytic sensitivity may be compromised by rare primer site mutations. Diagnostic errors can occur due to rare sequence variations.

Compliance Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test. However, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing. Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Components
Component Test Code*Component Chart NameLOINC
0051701Biotinidase (BTD), Allele 1
0051702Biotinidase (BTD), Allele 2
0051703Biotinidase (BTD), Interpretation
0051705Enzyme Activity
0051706Newborn Screen
0051707Symptoms
0051716Family History
2001340BTD MUT Specimen
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • BTD mutation testing