DNA von Willebrand Disease Type 2N
| Also Known as (Alias) | VWD genotyping |
| Method | polymerase chain reaction (PCR) based |
| Test Information | Von Willebrand Disease (VWD) is one of the most common inherited bleeding disorders. This disorder is divided into three types, Type 1, Type 2 and Type 3. All types of this condition cause prolonged bleeding episodes of varying severity; Type 1 is the mildest of the three types and Type 3 is the most severe. Type 2 is intermediate in severity and is further divided into four subtypes. Type 2A VWD is the most common form of Type 2, accounting for 70% of the Type 2 diagnosis
Mutations in the von Willebrand Factor (VWF) gene cause VWD. This disease can have different inheritance patterns. Type 1 and Type 2 (2A, 2B, and 2M) are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Type 3 and Type 2N are inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. |
| Additional Test Information | The Von Willebrand Factor Screen sequences up to 9 exons for mutations depending on the type. Confirmation is performed one of two ways. If the mutation creates/removes a restriction enzyme digestion site, the testing will be performed by RFLP. If a restriction enzyme digestion site is not present, testing will be done by sequencing the exon in which the mutation is located |
| Sample Requirements | EDTA (lavender top) |
| Requested Volume | 5-10cc EDTA (lavender top) tube OR
Analysis of amniocytes can be performed on cultured amniocytes. Two T-25 flasks of cells cultured to confluency will be accepted. Bloodworks Northwest does not have facilities to culture amniocytes. Bloodworks Northwest does not have facilities to culture amniocytes. |
| Shipping Information | Whole blood shipped at 4oC or ambient temperature is acceptable and should arrive in the lab within 48 hours.
Send samples to: |
| Requisition Form | Request for Testing Hemostasis Reference Laboratory |
| Transaction Code | 3250-09 |
| CPT Codes | 81405 |
| Turn around Time (analytic time) | 5-10 business days |
| Report/Results | Fax number required to receive report |