Newborn Metabolic Screening Program
Biotinidase Deficiency (BD) is caused by the lack of an enzyme
called biotinidase. Without treatment, this disorder can lead
to seizures, developmental delay, eczema, and hearing loss. Problems
can be prevented with biotin treatment.
The gene defect for biotinidase deficiency is unknowingly passed
down from generation to generation. This faulty gene only emerges
when two carriers have children together and pass it to their
offspring. For each pregnancy of two such carriers, there is
a 25% chance that the child will be born with the disease and
a 50% chance the child will be a carrier for the gene defect.
Studies show that 1 of every 60,000 live births will have biotinidase
Infants with biotinidase deficiency appear normal at birth,
but develop critical symptoms after the first weeks or months
of life. Symptoms include hypotonia, ataxia, seizures, developmental
delay, alopecia, seborrheic dermatitis, hearing loss and optic
nerve atrophy. Metabolic acidosis can result in coma and death.
With early diagnosis and treatment, all symptoms can be prevented.
Biotinidase deficiency is treated with daily biotin supplements,
which clear the skin rash and alopecia and improve the neurological
status in patients not diagnosed by screening.