congenital factor XII deficiency

Congenital factor XII deficiency is an inherited disorder that affects the body’s coagulation system. It is caused by defects in the coagulation factor XII, resulting from pathogenic variants in the F12 gene. The condition follows an autosomal recessive inheritance pattern, meaning that an affected individual inherits two copies of the defective gene. Although many individuals remain asymptomatic, abnormal laboratory findings such as a prolonged activated partial thromboplastin time and an increased risk for thromboembolism may lead to its diagnosis. Precise prevalence estimates are not available, making its occurrence difficult to quantify in the general population.

People with congenital factor XII deficiency are often identified through routine coagulation studies rather than overt clinical symptoms. In many cases, individuals do not experience significant bleeding problems, yet laboratory tests reveal a prolonged activated partial thromboplastin time. Some affected individuals may be at an increased risk for thromboembolic events, and there is a strong association with primary recurrent abortions. Not all individuals experience all of these features, and severity varies considerably from one person to another.

The condition results from pathogenic variants in the F12 gene, which encodes coagulation factor XII, a protein essential to the hemostatic pathway. Congenital factor XII deficiency is inherited in an autosomal recessive manner, meaning that an affected individual must inherit a defective copy of the gene from each parent. Parents who are carriers typically do not show symptoms, but they have a 25% chance with each pregnancy of having an affected child. Genetic counseling is recommended to help families understand the inheritance pattern and to explore family planning options.

Currently, management of congenital factor XII deficiency focuses on supportive care and symptom management, as there are no specific, FDA-approved treatments for this condition. Treatment is tailored to the individual and may involve routine monitoring for thromboembolic events as well as interventions to manage any complications that arise. A multidisciplinary care team is usually involved to ensure that any emerging issues are addressed promptly. Patients should discuss treatment options with their healthcare team, and genetic counseling is recommended to provide additional guidance.

The prognosis for congenital factor XII deficiency is variable; while many individuals remain asymptomatic, some may experience complications such as thromboembolic events or reproductive challenges. With current standards of care and careful monitoring, individuals can maintain a good quality of life. Outcomes vary depending on factors such as symptom severity, age at diagnosis, and access to specialized care. Outcomes described in medical literature continue to evolve as standards of care improve, and families often find it helpful to connect with genetic counselors and support groups for ongoing guidance.