Biotinidase Deficiency (BTD) 5 Mutations (INACTIVE as of 11/18/19: Refer to 0051730)
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).

Polymerase Chain Reaction/Capillary Electrophoresis
7-10 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Lavender (EDTA), pink (K2EDTA), or yellow (ACD solution A or B). 
Specimen Preparation
Transport 3 mL whole blood. (Min: 1 mL) 
Storage/Transport Temperature
Unacceptable Conditions
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.
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.

Statement C: Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Hotline History
View Hotline History
Component Test Code*Component Chart NameLOINC
0051701Biotinidase (BTD), Allele 1
0051702Biotinidase (BTD), Allele 2
0051703Biotinidase (BTD), Interpretation
0051705Enzyme Activity
0051706Newborn Screen
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 view this test within the Laboratory Test Directory found at
  • BTD mutation testing