Synonyms: giant platelet syndrome

This is a congenital bleeding disorder characterised by thrombocytopenia and large platelets.

Pathogenesis

The molecular defect involves the absence of a platelet membrane glycoprotein (platelet membrane von Willebrand factor) leading to defective platelet adhesion. This has been found to be caused by mutation in the GP1BA gene, the GP1BB gene, or the GP9 gene.¹ It is familial with autosomal recessive inheritance.²

Epidemiology

The syndrome is rare - estimated prevalence is less than 1 per million.³ Consanguineous marriages have been reported in the families of 81% of patients.⁴

Presentation

• Symptoms are of variable abnormal bleeding, including easy bruising, nosebleeds, mucosal bleeding, menorrhagia and, occasionally, gastrointestinal bleeding.
• Pregnancy in patients with Bernard Soulier syndrome is characterised by antenatal haemorrhage, intrapartum haemorrhage and postpartum haemorrhage, which may be delayed and severe.^5,6
• The severity of symptoms is very variable.
• Heterozygotes usually have no bleeding abnormality.³

Differential diagnosis

• May-Hegglin anomaly; autosomal dominant disorder of variable thrombocytopenia associated with purpura and bleeding, giant platelets and large inclusion bodies in the white cells
• Thrombocytopenia-absent radius syndrome.
• Von Willebrand's disease.
• Idiopathic thrombocytopenic purpura (ITP).
• Other inherited giant platelet disorders, e.g. grey platelet syndrome.

Investigations

• FBC and film: platelet count is usually low but may be normal. Giant platelets are seen on the blood film.
• Bleeding time is prolonged and may be longer than 20 minutes.
• Platelet aggregation studies: platelets do not aggregate in response to ristocetin or von Willebrand factor.
• Flow cytometry can demonstrate abnormalities of platelet membrane glycoprotein.⁷

Management

General measures

• For patients with moderate-to-severe symptoms, some restriction of activity, e.g. contact sports, may be necessary.
• The patient should be aware of the increased bleeding tendency when considering surgery.
• Avoid antiplatelet medication, e.g. aspirin.

Medical

In general, no medications are needed. Treatment of bleeding episodes includes:

• Antifibrinolytic agents, e.g. epsilon-aminocaproic acid, may be used for mucosal bleeding.
• For surgery or life-threatening haemorrhage, platelet transfusion is the only available therapy for surgery or life-threatening bleeding.⁸
• Desmopressin acetate (DDAVP®) has been shown to shorten the bleeding time in some patients with Bernard-Soulier syndrome.⁹ It does not work for all patients.¹⁰
• Recombinant activated factor VII has also been used.⁹

Complications

• The patient may develop antiplatelet antibodies due to the presence of glycoproteins Ib/IX/V which are present on the transfused platelets but absent from the patient's own platelets.
• Therefore platelet transfusions should be reserved for surgery or potentially life-threatening bleeding.

Prognosis

The tendency to bleed easily lasts for life but may decrease as the patient gets older.³

Document references

1. Giant Platelet Syndrome, Online Mendelian Inheritance in Man (OMIM)
2. Pham A, Wang J; Bernard-Soulier syndrome: an inherited platelet disorder. Arch Pathol Lab Med. 2007 Dec;131(12):1834-6. [abstract]
3. Geil JD; Bernard-Soulier Syndrome, eMedicine, Jun 2009
4. Toogeh G, Keyhani M, Sharifian R, et al; A study of Bernard-Soulier syndrome in Tehran, Iran. Arch Iran Med. 2010 Nov;13(6):549-51. [abstract]
5. Prabu P, Parapia LA; Bernard-Soulier syndrome in pregnancy. Clin Lab Haematol. 2006 Jun;28(3):198-201. [abstract]
6. Peitsidis P, Datta T, Pafilis I, et al; Bernard Soulier syndrome in pregnancy: a systematic review. Haemophilia. 2010 Jul 1;16(4):584-91. Epub 2010 Jan 12. [abstract]
7. Linden MD, Frelinger AL 3rd, Barnard MR, et al; Application of flow cytometry to platelet disorders. Semin Thromb Hemost. 2004 Oct;30(5):501-11. [abstract]
8. Kostopanagiotou G, Siafaka I, Sikiotis C, et al; Anesthetic and perioperative management of a patient with Bernard-Soulier syndrome. J Clin Anesth. 2004 Sep;16(6):458-60. [abstract]
9. Lanza F; Bernard-Soulier syndrome (hemorrhagiparous thrombocytic dystrophy). Orphanet J Rare Dis. 2006 Nov 16;1:46. [abstract]
10. Lopez JA et al; Bernard-Soulier syndrome. Blood. 1998 Jun 15;91(12):4397-418.

Acknowledgements