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California Newborn Screening Program

Biotinidase Deficiency (BD)


What is Biotinidase?

BD stands for “biotinidase deficiency.” This results in problems using biotin, a member of the B vitamin complex

family, which is needed for digestion or metabolism of food. BD occurs when an enzyme called biotinidase is either

missing or not enough of this enzyme is made. Biotinidase helps our body process biotin from the foods we eat and reuse the

biotin. Biotin is important to the health of skin, hair, bone marrow, and the nervous system.


There are two types of BD, partial and profound

Babies with partial BD have a certain level of the enzyme biotinidase in their blood. This level is between 10-30% of the normal

biotinidase levels. These babies do not have symptoms but may develop some symptoms at times of stress like when they are

sick or have a poor diet.


Babies with profound BD have no activity or less than 10% of enzyme activity. Profound biotinidase deficiency is a more severe

form of the disease.


What are the symptoms?

If left untreated, babies will develop symptoms that can include skin rash, poor muscle tone, developmental delay

(mental retardation), seizures, hearing loss, vision problems, hair loss and some life-threatening conditions. The severity

and types of symptoms can vary from child to child. Symptoms can show up as early as one week of age but are

usually seen between 3-6 months of age if untreated.


What is the treatment?

Since people with this disease are unable to use the biotin from the food in their diet or recycle the biotin, a special

biotin supplement must be taken every day shortly after birth. Treatment is life long. With proper treatment, BD is not a

life-threatening disease. Babies treated before symptoms appear usually do not develop any symptoms of the disease

later in life.


With early detection and treatment before symptoms appear, children with this disease do well. They are like any other children

except they need to take daily doses of biotin. In addition, regular visits to the baby’s doctor and scheduled visits to a special

clinic called a metabolic center are needed to maintain normal health, growth and development.


Parents' Guide to Biotinidase (PDF) 


Last modified on: 8/23/2010 2:25 PM