Home > Gene Browser > F9

F9

Synonyms
F9 p22, FIX, HEMB, P19, PTC, THPH8
External resources
Summary
This gene encodes vitamin K-dependent coagulation factor IX that circulates in the blood as an inactive zymogen. This factor is converted to an active form by factor XIa, which excises the activation peptide and thus generates a heavy chain and a light chain held together by one or more disulfide bonds. The role of this activated factor IX in the blood coagulation cascade is to activate factor X to its active form through interactions with Ca+2 ions, membrane phospholipids, and factor VIII. Alterations of this gene, including point mutations, insertions and deletions, cause factor IX deficiency, which is a recessive X-linked disorder, also called hemophilia B or Christmas disease. Alternative splicing results in multiple transcript variants encoding different isoforms that may undergo similar proteolytic processing.

Variant Counts

Variant classification counts, according to ACMG guideline on all identified variants among our tested samples, are listed. The variants with over 5% variant frequency in population genome databases ( gnomAD, dbSNP, etc.) are excluded.

Pathogenic
2
Likely pathogenic
1
VUS
1,790
Likely benign
516
Benign
45

Patient Phenotypes

Proportions of phenotypes among 3 patients carrying pathogenic or likely pathogenic variants on F9 gene are displayed below. The following symptoms were found in patients with a variant in F9. However, patients may have been diagnosed with a different variant.

Phenotype class
Patients in 3billion (%)
Abnormality of the integument
66.7%
Abnormality of head or neck
33.3%
Abnormality of the cardiovascular system
33.3%
Abnormality of the ear
33.3%
Abnormality of the immune system
33.3%
Abnormality of the musculoskeletal system
33.3%
Abnormality of the respiratory system
33.3%
Abnormal cellular phenotype
0%
Abnormality of blood and blood forming tissues
0%
Abnormality of limbs
0%
Abnormality of metabolism homeostasis
0%
Abnormality of prenatal development or birth
0%
Abnormality of the breast
0%
Abnormality of the digestive system
0%
Abnormality of the endocrine system
0%
Abnormality of the eye
0%
Abnormality of the genitourinary system
0%
Abnormality of the nervous system
0%
Abnormality of the thoracic cavity
0%
Abnormality of the voice
0%
Constitutional symptom
0%
Growth abnormality
0%
Neoplasm
0%

Have a question or need assistance? Ask here.

Send us your questions or comments related to the variant counts and/or patient phenotypes.