Invitae Biotinidase Deficiency Test

Casandra

Casandra Test Code IN06194Version 1 (DRAFT)

Performing Lab

Lab Invitae CorporationLab Test ID 06194

Invitae Biotinidase Deficiency Test

Clinical Use

Use

The Invitae Biotinidase Deficiency Test analyzes the gene BTD, which is associated with biotinidase deficiency. This test is useful for the diagnosis of patients in whom biotinidase deficiency is suspected due to clinical symptoms, abnormal newborn screening results, or biochemical findings. Profound biotinidase deficiency, characterized by less than 10% of residual activity, if untreated, can lead to various symptoms like hypotonia, seizures, alopecia, and metabolic issues. Early intervention with pharmacologic doses of biotin is crucial to prevent irreversible neurologic damage. Partial deficiency, the most common subtype, typically involves 10%–30% activity and can detect asymptomatic individuals through newborn screenings. If untreated, this condition can lead to enzyme deficiency affecting biotin-dependent carboxylases.

Special Instructions

This test is useful for the diagnosis of patients where biotinidase deficiency is suspected due to clinical symptoms, abnormal newborn screening results, or biochemical findings. Ordering must consider the patient's clinical context and symptomatology. Ensure samples are collected and submitted as per instructions to avoid delays.

Limitations

The test uses NGS technology to analyze clinically important regions, but variants outside these regions, complex structural rearrangements, or within specific sequence complexities may not be detected. It may not be possible to fully resolve mosaicism, phasing, or mapping ambiguities. Additionally, in rare collection scenarios like recent blood transfusions, analyzed DNA may not represent the patient’s constitutional genome. Copy number detection might be limited in certain single-exon events due to sequence properties.

Test Details

New York Approved