Harris platelet syndrome (HPS) is the most common inherited

giant platelet disorder Giant platelet disorders, also known as macrothrombocytopenia, are rare disorders featuring abnormally large platelets, thrombocytopenia and a tendency to bleeding. Giant platelets cannot stick adequately to an injured blood vessel walls, resultin ...

Presentation

HPS was identified among healthy blood donors in the north-eastern part of the Indian subcontinent, characterized by absent bleeding symptoms, mild to severe

thrombocytopenia Thrombocytopenia is a condition characterized by abnormally low levels of platelets, also known as thrombocytes, in the blood. It is the most common coagulation disorder among intensive care patients and is seen in a fifth of medical patients a ...

(platelets rarely < 50 × 10⁹/L) with giant platelets (Mean platelet volume 10fL) and normal platelet aggregation studies with absent

MYH9 Myosin-9 also known as myosin, heavy chain 9, non-muscle or non-muscle myosin heavy chain IIa (NMMHC-IIA) is a protein which in humans is encoded by the ''MYH9'' gene. Non-muscle myosin IIA (NM IIA) is expressed in most cells and tissues where it ...

mutation. In the blood donors with HPS authors found a statistically higher MPV, RDW and a lower platelet count and platelet biomass.

Diagnosis

At present the diagnosis of HPS is made by ascertaining the ethnicity of the patient, as well as assessing for conditions causing acquired thrombocytopenias, and after also excluding the known inherited giant platelet disorders(IGPD) and other congenital thrombocytopenias. Unfortunately some patients with IGPD are treated inappropriately with corticosteroids, immunoglobulin infusions and even

splenectomy A splenectomy is the surgical procedure that partially or completely removes the spleen. The spleen is an important organ in regard to immunological function due to its ability to efficiently destroy encapsulated bacteria. Therefore, removal of ...

Treatment

Prevalence

It is extremely important to recognize Harris platelet syndrome, as one third the population of certain parts of Indian subcontinent is affected.

Terminology

In 2002, this syndrome was called "asymptomatic constitutional macro thrombocytopenia" (ACMT). In 2005, to avoid confusion between ACMT and

congenital amegakaryocytic thrombocytopenia Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare inherited disorder. Presentation The primary manifestations are thrombocytopenia and megakaryocytopenia, or low numbers of platelets and megakaryocytes. There is an absence of megakaryo ...

(CAMT) this CAMT entity was referred as Harris platelet syndrome.

References

{{DEFAULTSORT:Harris Platelet Syndrome Coagulopathies Syndromes