Biotinidase Quantitative

Biotinidase deficiency is an autosomal recessive disorder caused by the mutation in the biotinidase gene. It leads to decreased absorption of biotin from the intestine. This condition can hamper the newborn’s growth as biotin is one of the major components in food, breast milk, and infant formula.

Biotinidase Quantitative Test - Overview

A biotinidase deficiency test is included in the screening panel for newborns to rule out this genetic disorder. The blood sample undergoes drying and multiple enzymatic assays to test biotinidase activity.

Clinical advancement has led to the development of test kits that allow pathologists to analyse the samples through fluorescence. A simple fluorescence test gives the accurate result.

However, detailed tests allow the doctor to compare the sample value to the standard cut-off and analyse the results accordingly. This determines the extent to which an enzyme performs its usual activity in the blood.

After confirming the results in preliminary tests, one can also opt for a follow-up test that includes serum or plasma testing. This is advisable for newborns who have received abnormal results in their blood samples.

Serum testing requires parental samples as well since it is an inherited disorder. They are not necessary if the symptoms occur at an adult stage or older age. However, it is mandatory for newborn screening.

The primary sample for testing and the parent’s sample for comparison must be collected simultaneously. This prevents manual errors, mishandling, and variability that might arise due to differences in time of collection.

Who Should Get Tested?

Biotinidase deficiency affects the growth and development of the baby. The symptoms include vision and hearing loss, seizures, hair loss, and skin rashes. However, some of these symptoms indicate that the condition is irreversible.

Newborn screening can easily differentiate between profound and partial biotinidase deficiency. When the biotinidase quantitative test results reflect the status of the disorder on time, it becomes easier to start biotin therapy.

With timely therapy and early diagnosis through biotinidase quantitative, parents can achieve the asymptomatic stage for their newborn.

Genetic testing helps in giving final confirmation about the severity of the disorder. For parents who reflect a partial deficiency in biotinidase quantitative tests, genetic screening can help their newborn manage the condition.  
 

Medically reviewed by Dr. S V S Sreedhar, Paediatrics, Apollo Hospitals, Jubilee Hills, Hyderabad.