Bernard–Soulier syndrome

Overview

Bernard–Soulier syndrome (BSS) is a rare inherited bleeding disorder characterized by a deficiency or dysfunction of the glycoprotein complex on the surface of platelets, which is essential for normal blood clotting. This condition leads to prolonged bleeding times and increased bleeding risk, even after minor injuries. First described in 1948 by Jean Bernard and Jean Pierre Soulier, BSS is categorized as a platelet function disorder rather than a clotting factor deficiency, and it is typically diagnosed in infancy or early childhood.

Causes

Bernard–Soulier syndrome is caused by genetic mutations that affect the function of the glycoprotein Ib-IX-V complex, which allows platelets to bind to von Willebrand factor — a key step in forming a platelet plug during blood clotting. Mutations in one of the following genes can cause BSS:

• GP1BA

• GP1BB

• GP9

The syndrome is usually inherited in an autosomal recessive manner, meaning a child must inherit one defective gene from each parent to be affected. Carriers (with only one mutated gene) typically do not show symptoms.

Symptoms

Individuals with Bernard–Soulier syndrome often present with bleeding-related symptoms, which can vary in severity. Common signs and symptoms include:

• Easy bruising

• Frequent nosebleeds (epistaxis)

• Excessive bleeding after injuries or surgeries

• Prolonged bleeding during menstruation (menorrhagia)

• Bleeding from gums

• Rarely, internal bleeding, especially in severe cases

Symptoms often appear in infancy or early childhood and may be confused with other bleeding disorders if not properly evaluated.

Diagnosis

Diagnosis of Bernard–Soulier syndrome involves a combination of clinical history, laboratory testing, and genetic analysis. Key diagnostic methods include:

• Complete blood count (CBC) – may show a normal or low platelet count and abnormally large platelets (macrothrombocytes)

• Bleeding time – typically prolonged

• Platelet aggregation tests – show defective aggregation in response to ristocetin

• Flow cytometry – used to assess the presence of the glycoprotein Ib-IX-V complex on platelets

• Genetic testing – confirms mutations in the GP1BA, GP1BB, or GP9 genes

It is important to distinguish BSS from other disorders such as von Willebrand disease and immune thrombocytopenia.

Treatment

There is no cure for Bernard–Soulier syndrome, but treatment focuses on preventing and managing bleeding episodes. Management strategies include:

• Avoidance of medications that impair platelet function (e.g., aspirin, NSAIDs)

• Antifibrinolytic agents such as tranexamic acid for mild bleeding episodes or dental procedures

• Platelet transfusions – reserved for severe bleeding or surgical procedures

• Hormonal therapy – used in females to control heavy menstrual bleeding

• Genetic counseling – for affected families planning to have children

Patients should also wear medical alert identification and be managed in collaboration with a hematologist.

Prognosis

With proper medical care and bleeding precautions, individuals with Bernard–Soulier syndrome can live relatively normal lives. While the condition is lifelong, many people manage it effectively through education, lifestyle adjustments, and prompt treatment of bleeding events. The main risks include bleeding complications from surgery, trauma, or childbirth. Regular follow-up with a hematology specialist is essential to optimize long-term outcomes.