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Long-Read Sequencing

Comprehensive Analysis of Hemophilia (CAHEA)

One-Stop Genetic Solutions for Hemophilia A and B

Challenges in Standard Hemophilia Testing

Hemophilia diagnosis and carrier testing often involve multiple steps. Coagulation testing helps establish the diagnosis for severe patient, but normal clotting times or factor activity levels do not reliably exclude carrier status or borderline patient.

 

Molecular testing provides more definitive information, yet the diverse variants in F8 and F9 ¹ often require different assays. Testing for hemophilia A commonly begins with targeted assays for F8 intron 1/22 inversions, followed by sequencing and deletion/duplication analysis as needed. Hemophilia B testing generally focuses on non-spot F9 sequence variant. This stepwise approach can prolong time to a molecular diagnosis, while complex variants may remain unresolved.

Information derived from reference ¹

Streamline Screening and Diagnostics with LRS

Comprehensive Analysis of Hemophilia (CAHEA) is an all-in-one hemophilia A & B testing solution that detects diverse mutations. Unlike NGS and Sanger sequencing, which are often limited to small mutations, or PCR assays that target only specific variants, CAHEA offers a unified, one-stop approach with 100% accuracy in F8 ² and F9 ³ genes. This replaces complex multi-test protocols with one simple, cost-effective workflow.

Send-out Testing

When considering our send-out sequencing services:

  1. Consultation: Contact our team for the most current test specifications.

  2. Sample Preparation: Check sample types and shipment requirements to ensure high-quality results. Please check your local export regulations and logistics partners.

  3. Submission: Contact Xcelom when placing an order. Include the completed Test Request and Consent Form, along with any required documents.

Sample Requirements

Peripheral Blood: 2 mL in EDTA tube

Dried Blood Spot (DBS): 3 spots, ≥ 8mm diameter each

gDNA*: >10 ng/uL and >30 nL

*gDNA extracted from amniotic fluid is accepted. Please include maternal sample for STR to exclude maternal contamination.

Transport Conditions

2-8℃, arrive within 72 hours

Testing Scope

Basic Panel

Targeted detection of common structural variants in the F8 gene:

  • Intron 1/22 inversions

  • Exon 22 deletions/duplications

Comprehensive panel

Detects hemophilia related variants, including:

  • F8 gene: Intron 1/22 inversions, exon 22 deletions/duplications, P/LP/selected VUS SNVs/InDels, and selected P/LP/VUS deletions/duplications

  • F9 gene: P/LP/selected VUS SNVs/InDels, and selected P/LP/VUS deletions/duplications

  • VWF gene: Potentially clinically significant SNVs/InDels in exons 18-28 (the region responsible for binding factor VIII (F8))

Prenatal Comprehensive Panel

  • Detects hemophilia related variants, including:

  • F8 gene: Intron 1/22 inversions, exon 22 deletions/duplications, P/LP SNVs/InDels, and selected P/LP deletions/duplications

  • F9 gene: P/LP SNVs/InDels, and selected P/LP deletions/duplications

  • VWF gene: P/LP SNVs/InDels in exons 18-28 (the region responsible for binding factor VIII (F8))

Turnaround Time (TAT)

17 working days

Resources

References:

1. Johnsen JM, Fletcher SN, Dove A, et al. Results of genetic analysis of 11 341 participants enrolled in the My Life, Our Future hemophilia genotyping initiative in the United States. J Thromb Haemost. 2022;20(9):2022-2034.

2. Liu Y, Li D, Yu D, et al. Comprehensive Analysis of Hemophilia A (CAHEA): Towards Full Characterization of the F8 Gene Variants by Long-Read Sequencing. Thromb Haemost. 2023;123(12):1151-1164.

3. Shi M, Ma Y, Peng X, et al. Clinical validation and application of targeted long-range polymerase chain reaction and long-read sequencing-based analysis for hemophilia: experience from a hemophilia treatment center in China. J Thromb Haemost. 2024;22(12):3431-3447.

 

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