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Biotinidase Deficiency
BTD gene
Biotinidase deficiency is an autosomal recessive disorder of biotin metabolism. Patients are classified as having either a profound or partial deficiency based on measurement of biotinidase activity in serum. Clinical features of profound untreated biotinidase deficiency include seizures, ataxia, hypotonia, developmental delay, alopecia, hearing loss, eye problems, skin rash, lactic acidosis and ketosis. Onset of symptoms usually occurs by several months of age but may occur during late childhood or adolescence. Partial biotinidase deficiency may exhibit any of the above symptoms but the symptoms are usually milder and may only occur during periods of metabolic stress. The symptoms of biotinidase deficiency can be prevented by administration of oral biotin making this disorder highly amenable to newborn screening programs in the U.S. and worldwide. However, once the eye, hearing problems, and developmental delay occur, they may be irreversible. In patients with either profound or partial biotinidase deficiency, mutation analysis identified a sequence variant in greater than 99% of alleles.
Using genomic DNA, bi-directional sequence of the coding region and splice junctions of the BTD gene is analyzed. Carrier testing and prenatal diagnosis is available once the mutation in the family has been defined.
Information Sheet, including prices and CPT codes
Consent Document
Genetic Test Sample Submission Form (Test Requisition Form) including Payment Options
Multiple Carboxylase Deficiency, Late-Onset; Multiple Carboxylase Deficiency, Juvenile-Onset; BTD Deficiency; co-enzyme, urine organics, newborn screening
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