SNP Shot: Genomic Insights

Factor XI deficiency is a bleeding disorder resulting from insufficient levels of factor XI, a protein crucial for blood coagulation. The condition's severity is categorized as either partial or severe, depending on the extent of the factor XI protein shortage. Notably, most individuals with factor XI deficiency, regardless of the severity, experience only mild bleeding issues, and some may even be asymptomatic. The primary symptom is prolonged bleeding following trauma or surgical procedures, particularly affecting the mouth, nose (oral and nasal cavities), or urinary tract. Post-surgical bleeding, if unaddressed, can lead to the formation of hematomas, which are solid masses of clotted blood, in the surgical area.

Other potential indicators of this disorder encompass frequent nosebleeds, easy bruising, subcutaneous bleeding, and gum bleeding. Women may experience heavy or extended menstrual periods (menorrhagia) or prolonged postpartum bleeding. Unlike some other bleeding disorders, spontaneous bleeding within the urinary tract (hematuria), gastrointestinal tract, or cranial cavity is uncommon in factor XI deficiency, though it can occur in severe cases. Muscle or joint bleeding, which can lead to chronic disability in other bleeding disorders, is generally not observed in this condition.

Inheritance:

Severe factor XI deficiency typically follows an autosomal recessive inheritance pattern. This means that both copies of the F11 gene within each cell must carry mutations for the disorder to manifest. In such instances, both parents are carriers of one mutated gene copy and exhibit partial factor XI deficiency, rarely displaying significant symptoms. In some families, the disorder is inherited in an autosomal dominant manner, where a single altered F11 gene copy in each cell is enough to cause the condition. In these instances, one parent of an affected individual also has the condition. Acquired factor XI deficiency, on the other hand, is not inherited and does not have a familial pattern.