Clinical description
Congenital FX deficiency manifests at any age but in general, severe forms of the disease manifest early in life. Patients may experience severe umbilical cord stump bleeding, recurrent epistaxis, soft-tissue hemorrhages, menorrhagia, easy bruising, intra cranial hemorrhages, hematuria, hemarthroses and excessive bleeding during or following surgery or delivery or trauma.

Etiology
Inherited congenital FX deficiency is caused by mutations in the F10 gene (13q34) controlling the production of plasma FX. The severity of the bleeding manifestations correlates with the FX level.

Diagnostic methods
Diagnosis is based on prolonged prothrombin, activated partial thromboplastin, and Russell viper venom times (PT, aPTT, RVVT), and on reduced levels of FX. Molecular testing is available, but unnecessary for diagnosis.

Differential diagnosis
Differential diagnoses include deficiencies of factors II, V, VII, VIII, IX, XI, XIII or acquired deficiencies in FX (amyloidosis).

Genetic counseling
Transmission is autosomal recessive. Genetic counseling should be offered to at-risk couples (both individuals are carriers of a disease-causing mutation) informing them of the 25% risk of having an affected child at each pregnancy. Heterozygote patients most often remain asymptomatic.

The information is taken from the website Orpha.net