Biotinidase test is carried out to identify the deficiency of biotinidase, which is an autosomal recessive disorder caused by mutations in the biotinidase gene (BTD). BIOT is an inherited condition in which the body is unable to reuse and recycle the vitamin biotin. This condition may be detected in newly born infants and also in adults. If this condition is not recognized and treated, its signs and symptoms typically appear within the first few months of life, although it can also become apparent later in childhood.The screening of biotinidase deficiency is included in the screening programme of newly born infants.