Biotinidase deficiency is a metabolic disorder, usually present in nature, in which the body loses its ability to use and recycle the vital vitamin called biotin (vitamin B7). Biotin plays a role in many critical functions, including energy production, nervous system health, and skin regeneration.
Deficiency of the biotinidase enzyme that activates this vitamin can lead to serious health problems, especially in infancy and childhood.
- Contents
- What is Biotinidase Deficiency?
- What Causes Biotinidase Deficiency?
- Frequently Asked Questions
What is Biotinidase Deficiency?
Biotinidase deficiency is a rare but potentially serious inherited metabolic disorder that occurs when the body cannot properly process biotin (vitamin B7), a water-soluble vitamin like thiamine.
What Causes Biotinidase Deficiency?
The problem with this disease is that an enzyme called biotinidase is not produced or does not function sufficiently. As a result of the deficiency of this enzyme, biotin cannot be used sufficiently by the body and vital functions are disrupted.
Causes of biotinidase deficiency:
- Genetic Mutations (BTD Gene Disorder)
- Consanguineous Marriages (Transfer of Carrier)
- Insufficiency in Enzyme Activity
- Nutritional Deficiency and Inadequacy
- Use of Antibiotics and Anticonvulsant Drugs
- Zinc Deficiency
- PregnancyPeriod Factors
- Metabolic Syndromes
- Unconsciousness
Genetic Mutations (BTD Gene Disorder)
The most important and direct cause of biotinidase deficiency is mutations in the BTD gene. This gene is responsible for the production of the biotinidase enzyme. Due to a genetic disorder, the enzyme is either not produced at all or very little is produced. Usually:
- The disease is inherited in an autosomal recessive manner.
- If both parents are carriers, there is a 25% chance that the child will have the disease.
- If screening is not performed, this disorder progresses silently and symptoms are noticed late.
- DNA analysis or enzyme activity test is required for detection.
Consanguineous Marriages (Transfer of Carrier)
Consanguineous marriage is a very important risk factor that increases the frequency of genetic diseases in society. When there is a high probability that family members carry the same mutation, the risk of developing biotinidase deficiency in children born from such marriages increases significantly.
- It is common in Türkiye, the Middle East and some Asian countries.
- Carrier status often goes unnoticed because carriers may not have any symptoms.
- Therefore, pre-pregnancy genetic screening tests are recommended.
Insufficiency in Enzyme Activity
In some individuals, the genetic mutation may be mild, in which case the enzyme is not completely absent, but works at a low level. In such individuals, deficiency symptoms are milder and appear later.
- It is called partial biotinidase deficiency.
- Symptoms usually become noticeable in adolescence or adulthood rather than in childhood.
- These patients generally need to take long-term biotin supplements.
Nutritional Deficiency and Inadequacy
Biotin is taken into the body both with food and produced by beneficial bacteria in the intestine. Habits such as excessive consumption of refined foods, low- protein diets, and constant consumption of raw egg whites reduce biotin absorption.
Unbalanced nutrition of infants and children, especially in developing countries, may increase this risk. Even without a genetic basis, biotin deficiency may worsen the disease.
Use of Antibiotics and Anticonvulsant Drugs
Some drugs can directly or indirectly disrupt biotin metabolism. In particular:
- Long-term antibiotic use: It disrupts the intestinal flora and causes a decrease in biotin-producing bacteria.
- Anticonvulsants (anti-seizure drugs): May cause biotin deficiency in the body by increasing the breakdown of biotin.
- Some acne medications can also affect vitamin balance.
Zinc Deficiency
In order for the biotinidase enzyme to work effectively, some auxiliary minerals are needed. The most important of these is zinc . Zinc deficiency contributes to biotin deficiency, especially by reducing the activity of enzymes that affect biotin metabolism.
Pregnancy Period Factors
If the mother’s increased vitamin and mineral needs are not met during pregnancy, the baby may develop biotin deficiency after birth. Severe vomiting in the mother , inadequate diet or incorrect supplement use may increase this risk. This condition is not hereditary but can be confused with congenital biotinidase deficiency.
Biotin levels should be taken into consideration during pregnancy follow-up.
- Malnutrition,
- Increased need for biotin,
- Conditions such as inadequate intake of supplements such as thiamine, folic acid, iron and zinc may indirectly affect the baby’s biotinidase activity. The deficiency becomes more evident after birth.
Metabolic Syndromes
Sometimes biotinidase deficiency is not seen alone. It may be together with diseases such as organic aciduria and urea cycle disorders. In such diseases, both the diagnosis becomes more complicated and the symptoms may become more severe.
- Therefore, metabolic panel tests should be performed together.
- A multidisciplinary approach is required to make a diagnosis.
Unconsciousness
One of the biggest problems is the lack of early screening. Since the requirement for metabolic screening tests varies between countries, some babies are diagnosed only after serious symptoms are seen.
However, newborn screening programs can detect this disease at an early stage with a simple heel prick test. Early treatment can completely restore the child’s quality of life to normal.
Frequently Asked Questions
What is biotinidase deficiency?
Biotinidase deficiency is the deficiency or dysfunction of the enzyme that allows the body to use the important vitamin called biotin (vitamin B7). This condition is usually a genetic disease that is present at birth. When the enzyme does not work, biotin cannot be recycled and a deficiency develops in the body. As a result, serious problems can occur in the nervous system, muscles and skin.
How is biotinidase deficiency diagnosed?
Symptoms of the disease usually begin in infancy. The most common symptoms are seizures, developmental delays, hearing loss, hair loss and skin problems. In some cases, symptoms may appear at a later age. Diagnosis is confirmed by a heel prick test (newborn screening) and enzyme level measurement.
Can biotinidase deficiency be treated?
Biotinidase deficiency can be completely controlled with appropriate treatment. Treatment is done with daily biotin (vitamin B7) supplements and can be continued for life. If treatment is started early, children can live completely healthy lives. If left untreated, serious neurological damage can occur.
Is biotinidase deficiency hereditary?
Biotinidase deficiency is inherited in an autosomal recessive manner. In other words, the defective gene must be received from both parents for the disease to occur. Parents are usually carriers but do not show any symptoms of the disease. Genetic counseling is especially important in families with consanguineous marriages.
Is biotinidase deficiency dangerous?
If it is not diagnosed and treated early, yes, it can be quite dangerous. It can cause serious consequences such as permanent hearing loss, neurological disorders and even coma. However, these risks can be largely eliminated with biotin supplements started on time. Early diagnosis is vital.
Is it possible to live with biotinidase deficiency?
With the right treatment, individuals with biotinidase deficiency can live a completely healthy and active life. It is necessary to take regular biotin supplements and not to skip check-ups. No major changes in diet or lifestyle are required. Regular medication continuation is sufficient.
Is biotinidase deficiency detected in newborn screening?
Biotinidase deficiency is tested in newborn heel blood screening. In this way, the disease can be diagnosed before it has any symptoms. Biotin treatment is started immediately in babies who are diagnosed. This screening test is very effective in preventing the effects of the disease.
What symptoms are seen in babies with biotinidase deficiency?
Biotinidase deficiency in babies usually manifests itself with some striking symptoms in the first months. The most common findings include muscle laxity, developmental delay, hair loss, skin redness and rashes. Recurrent seizures, hearing loss and breathing difficulties can also be observed. Since these symptoms can be confused with other diseases, early diagnosis and heel blood test are of great importance.
