Hemophilia-Complete Genetic Panel

Test Directory

Home Test Search Results Hemophilia-Complete Genetic Panel

Justification

The type of factor VIII (8) or factor IX (9) mutation correlates with bleeding tendency and risk of inhibitor formation. The high price of recombinant coagulation factor replacement or potential gene therapy makes confirming diagnosis an important consideration for clinicians. Importantly, VWD type 2N is often misdiagnosed as Hemophilia A due to similar functional laboratory results. The clinical sensitivity of this test is approximately 98% for Hemophilia A, 99% for Hemophilia B and 85% for subtypes 2A, 2B, 2N, 2M and 3 vWD. Hemophilia A and VWD testing can be influenced by numerous factors, such as inflammation, stress, infection, hormone replacement therapy, age, acute phase response, menstrual cycle, pregnancy, exercise, ABO blood type, or lupus anticoagulant, making traditional diagnosis a challenge.

STAT: < 48 hours (M-F)

NGS, Inversion Assay

Draw Tube: Purple Top

Sample Type: EDTA Whole Blood

DRAW KITS AVAILABLE

Specimen Requirements

	Sample Type	Volume Required	Minimum Volume	Stability
PREFERRED	EDTA Whole Blood	3mL	1mL	Room Temp.: 1 month Refrigerated: 1 month
ALTERNATIVE	Cheek swab	2 swab	-	Room Temp.: 1 month Refrigerated: 1 month

REJECTION CRITERIA	Sample contamination; sample compromised
SPECIAL INSTRUCTIONS	-

General Information

METHODOLOGY	NGS, Inversion Assay
STAT TAT	< 48 hours (M-F)
STAT TAT Performance	> 90% of results released in 48 hours
ROUTINE TAT	< 5 days (M-F)
ALTERNATIVE NAMES	Factor VIII genetic sequencing, von Willebrand genetic sequencing, Factor IX genetic sequencing, inversion testing, Hemophilia A, Hemophilia B, Christmas disease
DESCRIPTION	This test sequences the exons plus 5bp of the flanking introns of F8, F9, GP1BA, and VWF, plus deep intronic and promoter mutations that have been associated with disease. Additionally, this test looks specifically for the intron 1 and intron 22 inversions in F8 using custom PCR assays, which cause ~50% of severe hemophilia A cases. Sanger sequencing may be used to confirm variants as needed. Hemophilia A has a prevalence of 1:5000 (males). Hemophilia B has a prevalence of 1:25000. VWD occurs with bleeding symptoms at rate of 1 in 1,000 in the general population and in 10% of those cases the bleeding is severe. This prevalence makes VWD the most common congenital bleeding disorder known.
LIMITATIONS	This test will not detect variants located outside of the targeted DNA regions. This test is not optimized to detect chimerism or somatic mosaicism. This test will detect small indels but may miss larger deletions or duplications. Balanced structural variants will not be detected unless specifically targeted by a custom PCR assay.
NORMAL RANGE	Interpretation: Negative
ASSOCIATED TESTING	-
REFERENCES	1.) Santagostino E and Fasulo MR. Semin Thromb Hemost 2013;39(7):697-701; 2.) Aledort LM, Coates J. Am J Hematol. 2005 Jun;79(2):172-3. 3.) Kirtava A et al. Haemophilia 2004; 10(2): 158-161; 4.) James PD and Lillicrap, D. Br J Haematol 2013; 161: 166-176; 5.) Federici, AB. Int Jnl Lab Hem 2016; 38(Suppl. 1): 41-49; 6.) Leebeek, FWG and Eikenboom, JCJ. NEJM 2016; 375(21): 2067-2080; 7.) Lillicrap D and James, P. World Federation of Hemophilia 2009; No. 47.
SAMPLE REPORT	Upon request
NEW YORK STATE APPROVED	No

Test Codes

ORDER CODE	P1226
CPT CODE	81238, 81406, 81407, 81408
LOINC CODE	94234-2