Laboratory Test Guide

DNA Hemophilia A Mutation Evaluation (Sendout)

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

Factor VIII Gene (F8) Variant Database
Factor IX Gene (F9) Variant Database
CDC Hemophilia Mutation Project: CHAMP & CHBMP

Synonyms

3250-02, F8 Genotyping, HemA Genotyping, Hemophilia A

Interpretation

Method

Polymerase Chain Reaction (PCR) Based

Ref. Range Notes

See report.

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

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.

Performance

LIS Dept Code

Performing Location(s)

Sendout	Bloodworks Northwest Eastlake Genomics Laboratory 1551 Eastlake Ave E Suite 100 Seattle, WA 98102

Frequency

Turn around Time: 2-4 weeks from sample receipt at Bloodworks Eastlake Genomics.