DNA Hemophilia A Mutation Evaluation (Sendout)

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General Information

Lab Name
Lab Code
1102
External Test Id
3250-02
Description

Test Information: Severe patients that are negative for the DNA Factor VIII inversion or patients that have moderate or mild hemophilia can be evaluated for mutations. Through our current screening methods, a mutation is found ~90-95% of the time.

If the specific mutation cannot be identified, intragenic linkage is often useful to trace the affected allele through the family tree by following 5 polymorphic sites. Linkage studies also help identify the de novo origin of mutations in families with an isolated occurrence (eg: maternal grandparents). Intragenic linkage may be useful in 80-90% of families where key family members (patient and both parents of potential carrier) are available.

Additional Test Information: For approximately half of the severe hemophilia A patients (and moderate cases with FVIII levels of ~1%), the DNA Factor VIII Inversion will be negative. For these patients, along with the moderate and mild patients, the Hemophilia A Mutation Evaluation will be performed to identify the mutation. A MDE (mutation detection enhancement) screen will be performed initially and if needed, will be followed by a sequence screen. Once identified, the genotype will be tested by confirmation analysis.

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.

Ordering Requirements:

  • Orders from Washington Center for Bleeding Disorders (SEAWBD, ISEAWBD) and FHCC Hematology are pre-approved. Orders from other locations require Laboratory Medicine Resident approval.
  • Providers must submit a completed Bloodworks Eastlake Genomics Laboratory Requisition with all orders.
References
  1. Factor VIII Gene (F8) Variant Database
  2. Factor IX Gene (F9) Variant Database
  3. CDC Hemophilia Mutation Project: CHAMP & CHBMP
Forms & Requisitions
  • Bloodworks Northwest Eastlake Genomics Laboratory Requisition
Synonyms
3250-02, F8 Genotyping, HemA Genotyping, Hemophilia A
Components

Interpretation

Method

Polymerase Chain Reaction (PCR) Based

Reference Range
Ref. Range Notes

See report.

References
  1. Factor VIII Gene (F8) Variant Database
  2. Factor IX Gene (F9) Variant Database
  3. CDC Hemophilia Mutation Project: CHAMP & CHBMP

Ordering & Collection

Specimen Type
Blood
Collection

10 mL LAVENDER TOP EDTA tube

Forms & Requisitions
  • Bloodworks Northwest Eastlake Genomics Laboratory Requisition
Approval Required
Pre-approved for Washington Center for Bleeding Disorders (SEAWBD, ISEAWBD) and FHCC Hematology. Orders from other locations require LMR approval.
Handling Instructions

Outside Laboratories:

  • Refrigerate whole blood while awaiting shipment. Transport with a cold pack.
  • Expedite transport; samples must be received by Bloodworks within 72 hours of collection. Allow for an additional day of transport from UW-MT to Bloodworks Northwest.
  • Submit a completed Bloodworks Northwest Eastlake Genomics Requisition along with the DLMP Requisition.* Leave the billing section blank to be completed by Sendouts staff.
    • *Use client-specific requisition when available. To obtain a client-specific requisition, contact Client Support Services via email at: commserv@uw.edu.

Stability: Refrigerated (preferred): 72 hours; Ambient: 48 hours; Frozen: Approved for WA Center for Bleeding Disorders (-20°C or -70/80°C). Avoid thawing/re-freezing.

Quantity
Requested: 10 mL EDTA whole blood
Minimum: 5 mL EDTA whole blood

Processing

Receiving Instructions
  • Whole blood received at ambient temperature should be refrigerated. Ambient/refrigerated samples must be received at Bloodworks within 72 hours.*
  • Whole blood received frozen should be stored frozen and transported on dry ice. WA Center for Bleeding Disorders has pre-arranged with the BWNW Hemostasis Lab to send samples frozen to extend specimen stability.
  • If sample is collected on a Friday, notify Sendouts immediately upon sample receipt to ensure delivery to Bloodworks NW by the 1 p.m. cutoff.

Login: GSEND1-;REFRIG (or -;FREEZE, if received frozen)

  • GSNDT1: BWEGEN
  • GSTYP1: WB
  • GTSRQ1: ;DNA Hemophilia A Mutation Evaluation (Bloodworks Test 3250_02)

Sendouts:

  • Order Bloodworks Test: 3250-02.
  • A completed Bloodworks Northwest Eastlake Genomics requisition must accompany all samples.
  • Send samples with UW courier or Delivery Express courier.
  • Samples may be sent Monday through Friday only. If sent on a Friday, samples must be in lab at the Eastlake location by 1 p.m.
  • Ambient or refrigerated whole blood samples must arrive at Bloodworks within 72 hours of collection.*

Stability: Refrigerated (preferred): 72 hours; Ambient: 48 hours; Frozen: Approved for WA Center for Bleeding Disorders (-20°C or -70/80°C). Avoid thawing/re-freezing.

*Contact the Bloodworks NW Eastlake Genomics Lab at 206-568-2184 for sample acceptability questions prior to cancelling orders outside of the stated stability window.

Misc Sendout

Performance

Lab Department
Frequency
Turn around Time: 2-4 weeks from sample receipt at Bloodworks Eastlake Genomics.
Available STAT?
No
Performing Location(s)
Sendout Bloodworks Northwest Eastlake Genomics Laboratory

1551 Eastlake Ave E
Suite 100
Seattle, WA 98102

Billing & Coding

Billing Comments

CPT: 81407