Biotinidase | Laboratory research

General Information

Biotinidase is an enzyme involved in the conversion of biotin (vitamin B7). Biotin is involved in the breakdown of fats, carbohydrates and proteins. During the deficiency of the enzyme biotinidase, the exchange of biotin is disturbed, and with it, the above-mentioned metabolic processes are disturbed, which leads to the pathology of the nervous system, skin and many other systems.

Biotinidase deficiency is an autosomal recessive disorder and results from a mutation in the BTD gene. The clinical manifestation of the disease and the age of detection depend on the residual activity of the enzyme biotinidase.

The average frequency of profound biotinidase deficiency is 1 case per 137 live births, and the frequency of partial deficiency is 000:1 live births. The frequency of carrying a biotinidase gene mutation is on average 110:000.

Profound biotinidase deficiency It is clinically manifested in the first decade of life and is characterized by severe heart palpitations, ataxia (impaired coordination), developmental delay, sensory hearing loss, visual defects, skin lesions, and alopecia (baldness).

Partial deficiency of biotinidase results in milder clinical manifestations without damage to the nervous system.

Clinical manifestations of biotinidase deficiency are similar to the clinical picture of various enzymopathies, such as: holocarboxylase synthetase deficiency, carboxyl synthetase deficiency, methylcrotonylglycinuria, and others.

Determination of serum biotinidase allows for differential diagnostics between these diseases.

In the case of biotinidase deficiency, prophylactic supply of biotin to the body significantly improves the clinical condition, except for developmental delay, vision and hearing damage.

When is the survey conducted?

• Newborn screening
• Adults - with clinical signs of biotinidase deficiency

Material for examination: Venous blood

Reference limits:  4.2 – 12.8 units/l

Taking high doses of biotin supplements may affect a number of research parameters (thyroid hormones, vitamin D determination, etc.).