Biotinidase Deficiency (BTD) Sequencing
Also known as: BTD NGS
Use
Biotinidase Deficiency (BTD) Sequencing is used to confirm a diagnosis of biotinidase deficiency, which impairs the body's ability to recycle and reuse the vitamin biotin, resulting in neurologic and dermatologic symptoms. Profound BTD manifests with symptoms including ataxia, hypotonia, developmental delay, seizures, vision and hearing problems, alopecia, metabolic acidosis, organic aciduria, and hyperammonemia. Pathogenic germline variants in the BTD gene cause BTD, and the condition is inherited in an autosomal recessive manner. The clinical sensitivity of the test is approximately 99 percent in detecting BTD.
Special Instructions
Not provided.
Limitations
This test does not exclude a diagnosis of BTD if negative, as only variants within coding regions and intron-exon junctions are detected. It may miss deletions, duplications, insertions of any size, and deep intronic or regulatory region variants. Technical limitations can affect the detection due to pseudogenes, repetitive, or homologous regions. This test is not for detecting low-level mosaic or somatic variants, gene conversions, complex inversions, translocations, mtDNA mutations, or repeat expansions. Interpretation may be affected by previous allogeneic stem cell transplants, and non-coding transcripts are not analyzed.
Methodology
NGS (Targeted)
Biomarkers
LOINC Codes
- 66746-9 - Specimen type
- 53845-4 - BTD gene Mut Anl Bld/T
Result Turnaround Time
10-15 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
3 mL
Container
Lavender (EDTA) or yellow (ACD solution A or B). New York State Clients: Lavender (EDTA)
Causes for Rejection
Serum or plasma; grossly hemolyzed or frozen specimens
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 2 weeks |
| Frozen | Unacceptable |
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