quanti (decreased plt production)

May-Hegglin Anomaly

abnormally large platelets ( 20 misshapen morphology on PBF, and Döhle-like inclusions in neutrophils

May-Hegglin Anomaly

MYH9 gene

Sebastian Syndrome

large platelets, thrombocytopenia, and granulocytic inclusions

Sebastian Syndrome

mimics May-Hegglin but lacks its specific structural syndrome presentation

Fechtner Syndrome

Exhibits all the manifestations of Sebastian syndrome (large platelets, thrombocytopenia, granulocytic inclusions) plus deafness, cataracts, and nephritis.

Epstein Syndrome

Characterized by large platelets associated with deafness, ocular problems, and glomerular nephritis.

Thrombocytopenia with Absent Radius (TAR) Syndrome

severe neonatal thrombocytopenia, congenital absence or extreme hypoplasia of the radial bones, and short/malformed ulnae

Thrombocytopenia with Absent Radius (TAR) Syndrome

RBM8A gene on the long arm of chromosome 1 ($1\text{q}21.1$ deletion)

Congenital Amegakaryocytic Thrombocytopenia (CAMT)

complete bone marrow failure. Affected infants show severe thrombocytopenia at birth with petechiae and physical anomalies.

Congenital Amegakaryocytic Thrombocytopenia

MPL gene on Chromosome 1, causing a complete loss of Thrombopoietin (TPO) Receptor function.

Autosomal Dominant Thrombocytopenia

Incomplete differentiation leading to mild or absent bleeding. Platelet size, morphology, and function are completely normal.

Autosomal Dominant Thrombocytopenia

ANKRD26 gene

X-Linked Thrombocytopenia

Driven by mutations in the WAS (Wiskott-Aldrich Syndrome) gene or GATA1 gene

Neonatal Thrombocytopenia

Affects 1–5% of infants within 72 hours of birth.

Neonatal Thrombocytopenia

Common causes include TORCH syndrome (Toxoplasmosis, Other [HIV/Syphilis], Rubella, Cytomegalovirus, Herpes simplex virus) which typically yields small platelets (microthrombocytes), or neonatal sepsis/necrotizing enterocolitis.

Ineffective Thrombopoiesis

Megaloblastic Anemias and viral infections where platelet production is fundamentally disrupted despite the presence of megakaryocytes.

Acquired Drug-Induced Hypoplasia

Chemotherapeutic agents (methotrexate, busulfan, cytosine, cyclophosphamide, cisplatin), heavy alcohol ingestion, and estrogen drugs suppress bone marrow.