Test Catalog

Molecular diagnosis of congenital coagulopathies by NGS: Factor VII Deficiency

Code: 70805

Type: Estudi de coagulopaties congènites

Clinical information

Diagnostic Utility:

Identifying the molecular defect in F7 in patients diagnosed with Factor VII Deficiency (FVII).

Factor VII Deficiency (FVII)

FVII is a rare hereditary bleeding disorder caused by a decrease or absence of coagulation Factor VII (FVII). The estimated prevalence is around 1/300,000. The clinical expression of this disease varies greatly from lethal to moderate or even asymptomatic. There is no consistent relationship found between the severity of the bleeding syndrome and the residual levels of FVII activity. The clinical presentation can be very severe with early onset of intracranial hemorrhages or repetitive hemarthrosis; or conversely, moderate with cutaneous-mucosal bleeding (epistaxis, menorrhagia) or bleeding caused by surgical interventions. There are also many patients who are totally asymptomatic, despite having very low FVII levels.

FVII is inherited in an autosomal recessive manner and is caused by mutations in the F7 gene that encodes the coagulation Factor VII protein. More than 300 alterations have been identified in this gene. Mutations in the F7 gene lead to a decrease in circulating coagulation FVII. A deficiency of FVII prevents normal blood clotting, causing episodes of abnormal bleeding that can be severe.

Application of a multi-gene panel that is based on simultaneous amplification of exons and flanking intronic regions for sequencing through next-generation sequencing (NGS) techniques allows for the simultaneous molecular study of genes related to congenital coagulopathies and hereditary bleeding disorders, including the Factor VII (F7) gene.

Method:

Next-Generation Sequencing (NGS)

Next-Generation Sequencing of the exons and flanking intronic regions of F7.

Traditional Sanger sequencing to confirm the mutation(s) detected by NGS in patients diagnosed with FVII, in order to arrive at an unequivocal result, analyzing the specific region where the variant is located.

If no potential or definitively causative mutation is identified, it will be reported and discussed with the requesting medical team the possibility of carrying out complementary studies.

Reference Values

N/A

Diagnostic Algorithm:

N/A

Turnaround Time:

30 working days

Specimen information

Sample: Whole blood
Tube: EDTA K3 5-10 ml tube if it is a blood sample

Minimum essential volume: 3 ml

Stability:

  • At room temperature: 4 days
  • In the refrigerator: 10 days

Transport instructions: Preferably at room temperature

Reasons for rejection: Coagulated sample and/or incorrectly identified.

Other types of accepted samples:

  • Purified DNA, minimum 300 ng (30 ng/μL)
  • Buccal mucosa: contact the laboratory to inquire about specimen collection specifications.

Administrative information

BST Code: LRD2833
Test Description: Molecular diagnosis of congenital coagulopathies by NGS: Factor VII deficiency.
Synonyms: Genetic study of FVII, sequencing of F7.
Section: Congenital Coagulopathies
BST Rate: Check the updated rates here.

The DFVII box must be checked in the molecular study request form and the available phenotypic data must be completed.

Profiles:

Not applicable.

References

  • Peter J Hulick. Next-generation DNA sequencing (NGS): Principles and clinical Applications. Waltham, MA: UpToDate Inc. https://www.uptodate.com
  • DNA Sequencing by Capillary Electrophoresis. Applied Biosystems Chemistry Guide. Second Edition.

 Base de dades de mutacions