Beta-mannosidosis: Beta-mannosidase Enzyme Analysis

Clinical Information

Beta-mannosidosis is one of the glycoproteinosis disorders, a subcategory of very rare lysosomal storage diseases. Patients with beta-mannosidosis typically have some degree of developmental delay or intellectual disability. Most of these patients have mild or no dysmorphic features. Behavior abnormalities, angiokeratomas, seizures, demyelinating peripheral neuropathy, and deafness have all been reported in association with beta-mannosidosis.

Technical Information

Enzyme activity is measured using a 4-methylumbelliferyl (4-MU) substrate.

Specimen Requirements

• Accepted sample types for this test include dried blood spots (DBS), fibroblasts, and leukocytes.
• DBS: Approximately 75 uL of blood should be applied to each of the five circles on filter paper dried blood spot card. Allow blood to dry for at least 4 hours before shipping.
• Fibroblasts: Tissue sample should be stored in sterile culture media; cultured fibroblasts should be sent in two T25 flasks. Do NOT place tissue in formalin or formaldehyde. Do not freeze tissue.
• Leukocytes: Minimum of 5 mL whole blood (7-10 mL preferred) collected in a sodium heparin tube

Transport Instructions

• DBS: Ship DBS card at ambient temperature
• Fibroblasts: Ship tissue sample or cultured fibroblasts at ambient temperature
• Leukocytes: Whole blood should be shipped at ambient temperature. If leukocytes are being isolated at another laboratory, the pellet should be frozen after specimen processing and shipped frozen on dry ice.