Alpha-Mannosidosis (MAN2B1) Sequencing
| Disorder | Alpha Mannosidosis | |
| Gene Name | MAN2B1 | |
| Clinical info | Alpha-Mannosidosis is an autosomal recessive lysosomal storage disorder caused a deficiency of alpha-mannosidase enzyme activity. This condition demonstrates variable expressivity with three clinical phenotypes described as mild (type I), moderate (type II), and severe (type III), with onset varying from prenatal loss with type III to after 10 years of age with type I. Features can include mild or moderate intellectual disability, abnormalities in motor function, hearing loss, dysostosis multiplex, immunodeficiency, cataracts/corneal opacities, hepatosplenomegaly, and characteristic facial features. | |
| Indications | The enzyme assay for alpha-mannosidase activity is considered diagnostic for alpha-mannosidosis. However, the enzyme assay is not a reliable method for carrier detection. Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis. | |
| Associated Tests | Oligosaccharides and mannosidase enzyme analysis are available through the GGC Biochemical Lab. | |
| Detection | Sequencing of the MAN2B1 gene can detect about 97.5% of the abnormal alleles in individuals with a biochemical diagnosis. | |
| Specimen Requirements | 5 to 10 ml of peripheral blood collected in an EDTA (lavender top) Vacutainer tube is preferred. The minimal blood needed for reliable DNA isolation is 3 ml | |
| Transport | The specimen should be kept at room temperature and delivered via overnight shipping. FedEx is preferred. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery. | |
| Turnaround time | 3 weeks | |
| Prenatal testing | Prenatal diagnosis is available if the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. Contact the laboratory prior to sending a prenatal specimen. | |
| CPT Codes | Unknown mutation Stacking Codes: 83898 (x5), 83904 (x10), 83909 (x10) 2013 Molecular Code: 81479 Known mutation Stacking Codes: 83898, 83904 (x2), 83909 (x2), 83912 2013 Molecular Code: 81479 |
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| Cost | $1500 for sequencing $350 for known mutation |
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| Contact | For further information contact This email address is being protected from spambots. You need JavaScript enabled to view it. , MS, Lab Counselor at 1-800-473-9411. | |
Form Needed
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Kellie King, MS, CGC
Molecular Diagnostic Lab
The Molecular Diagnostic Lab offers DNA analysis for many genetic disorders via gene sequencing, targeted mutation analysis, MLPA deletion/duplication testing, trinucleotide repeat analysis and next generation sequencing panels.