SNP Shot: Genomic Insights

Factor XIII deficiency is an uncommon bleeding disorder. It exists in two forms: an inherited type and a less severe, acquired type that develops during a person's life.

Inherited factor XIII deficiency usually manifests shortly after birth with unusual bleeding from the umbilical cord. Without treatment, individuals with this condition may experience excessive and prolonged bleeding episodes, potentially life-threatening. Bleeding can occur after surgery or minor injuries. Spontaneous bleeding into joints or muscles is also possible, resulting in pain and impaired function. Women with the inherited form often have heavy or prolonged menstrual periods (menorrhagia) and may suffer repeated miscarriages. Additional symptoms of inherited factor XIII deficiency can include nosebleeds, gum bleeding, easy bruising, poor wound healing, bleeding post-surgery, and abnormal scar formation. Furthermore, inherited factor XIII deficiency elevates the risk of bleeding within the brain (intracranial hemorrhage), which is a major cause of death in affected individuals.

Acquired factor XIII deficiency develops later in life. Individuals with the acquired form are less prone to severe or life-threatening bleeding episodes compared to those with the inherited form.

Inheritance:

Inherited factor XIII deficiency follows an autosomal recessive inheritance pattern. This means it occurs when both copies of either the F13A1 gene or the F13B gene in each cell contain mutations. Some individuals, including parents of children with factor XIII deficiency, carry only one mutated copy of the F13A1 or F13B gene in each cell. These carriers have lower levels of factor XIII in their blood (20-60% of normal) and might experience abnormal bleeding following surgery, dental procedures, or significant trauma. However, the majority of individuals carrying a single mutated copy of the F13A1 or F13B gene do not exhibit abnormal bleeding under normal conditions and therefore remain undiagnosed. The acquired form of factor XIII deficiency is not inherited and does not have a familial component.