Biotinidase Quantitative
About Biotinidase Quantitative test
This is a quantitative test used to measure the biotinidase enzyme activity and is a part of most newborn screening protocols. This test is used as the gold standard for confirming the diagnosis of biotinidase deficiency (BD), which is an autosomal recessive disorder. Biotin acts as a cofactor in carboxylase enzymes required for the synthesis of fats, proteins, and carbohydrates. Biotin is processed by the enzyme, biotinidase. Biotinidase deficiency takes place as a result of mutation in the BTD (biotinidase) gene.
If there is biotinidase deficiency, the child may experience optic atrophy, seizures, hypotonia, skin rash, and hair loss. Such children reportedly have ataxia and show developmental delays
Symptoms of biotinidase deficiency
Seizures
Decreased muscle tone
Ataxia
Developmental delay
Vision problems (e.g. blurred vision)
Hearing loss
Cutaneous abnormalities (e.g. skin rash)
When is a Biotinidase Quantitative test done?
To diagnose biotinidase deficiency in clinically symptomatic patients
To clarify molecular findings in the BTD gene
To follow up abnormal newborn screening results
To monitor patients undergoing treatment
Test preparation
No special preparation is required for the biotinidase quantitative test
Interpretation of the Test Results
The units of measurement for the results are nanomoles per minute per milliliter (nmol/min/mL)
|
Biotinidase status |
Reference range |
|
Normal |
5.5-17 |
|
Partial deficiency |
2.0-5.4 |
|
Deficient |
0-1.9 |
NOTE: Abnormal levels of the biotinidase enzyme can be observed in cases of significant biotinidase deficiency or partial deficiency (as indicated in the provided chart)
FAQs
How is the sample collected for Biotinidase Quantitative test?
A blood sample is collected by inserting a fine needle in a vein in your arm. Usually, the entire process does not take more than 5 minutes
What are the risks associated with Biotinidase Quantitative test?
This test involves minimal risk. Slight tenderness or soreness might develop at the place where the needle was inserted. This usually resolves on its own after a while. Rarely, the sight can become infected
What is the turnaround time (TAT) for this test?
The usual turnaround time (TAT) for obtaining the results for the biotinidase quantitative test is 48 hours/2 working days. Test results might be mailed or made available online through health portals
What is the function of the biotinidase enzyme?
Biotinidase enzyme is responsible for recycling the vitamin biotin. The enzyme also makes biotin available from bound dietary sources
Can an adult be biotinidase deficient?
Usually, biotinidase deficiency is diagnosed in newborns as part of neonatal screening. However, an adult between 20-30 years may develop initial symptoms of adult-onset BD
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