|Clinical Use:||Biotinidase is the preferred test for diagnosing biotinidase deficiency and can be used as a follow up test for certain organic acidurias.|
|Background:||Biotinidase deficiency is an autosomal recessive metabolic disease in which biotin is not released from proteins during digestion or normal cellular protein turnover.
Symptoms of the disease are caused by the inability to re-use biotin.
Untreated profound biotinidase deficiency typically manifests within the first decade of life as seizures, ataxia, developmental delay, hypotonia, sensorineural hearing loss, vision problems, skin rash, and/or alopecia. Partial biotinidase deficiency is associated with a milder clinical presentation, which may include cutaneous symptoms without neurologic involvement. Certain organic acidurias, such as holocarboxylase synthase deficiency, isolated carboxylase synthase deficiency and 3-methylcrotonylglycinuria, present similarly to biotinidase deficiency. Serum biotinidase levels can help rule out these disorders.
Treatment with biotin is successful in preventing the clinical features associated with biotinidase deficiency. In symptomatic patients, treatment will reverse many of the clinical features except developmental delay and vision and hearing complications
|Reference Ranges:||0 – 6 month: 2.1 – 8.0 nmol/mL/min
6 month – 115 years: 2.4 – 8.2 nmol/mL/min
|Patient Preparation:||None required|
|Specimen Requirements:||Blood specimen in a Lithium Heparin (green top) Tube or paediatric equivalent.|
|Turnaround Time:||1 week|
|Referred Test:||Referred test|
|Location:||Paediatric Metabolic Centre|