This title slide introduces Congenital Amegakaryocytic Thrombocytopenia (CAMT). The subtitle covers its definition, genetics, clinical features, and management.

Congenital Amegakaryocytic Thrombocytopenia (CAMT)

Definition, Genetics, Clinical Features & Management

This rare autosomal recessive disorder, caused by MPL gene mutations at 1p34, features severe thrombocytopenia at birth and absent megakaryocytes. It progresses to pancytopenia by age 2-4 years, with an incidence of less than 1 per million births.

Definition & Epidemiology

• Rare autosomal recessive disorder (MPL gene mutations, 1p34)
• Severe thrombocytopenia at birth, absent megakaryocytes
• Progresses to pancytopenia by age 2-4 years
• Incidence <1 per million births

Source: CAMT Presentation

This workflow depicts the pathophysiology of MPL mutations (biallelic on chromosome 1p34), causing defective TPO receptor signaling, impaired megakaryopoiesis, and megakaryocyte aplasia leading to severe congenital thrombocytopenia. It progresses to broader hematopoietic lineage failure, resulting in bone marrow aplasia and pancytopenia.

Etiology, Genetics & Pathophysiology

{ "headers": [ "Step", "Mechanism", "Effect" ], "rows": [ [ "MPL Mutation", "Biallelic mutations in MPL gene (chromosome 1p34)", "Defective thrombopoietin (TPO) receptor signaling" ], [ "Receptor Defect", "Impaired TPO-R activation and downstream signaling", "Impaired megakaryopoiesis and maturation" ], [ "Megakaryocyte Aplasia", "Absent or severely reduced megakaryocytes in bone marrow", "Severe thrombocytopenia from birth" ], [ "Progressive Failure", "Expansion to other hematopoietic lineages", "Bone marrow failure leading to pancytopenia" ] ] }

Source: Congenital Amegakaryocytic Thrombocytopenia (CAMT)

Clinical features include neonatal petechiae, purpura, and mucosal bleeding, progressing to anemia, recurrent infections, and pancytopenia. Lab findings reveal isolated thrombocytopenia with normal initial RBC/WBC in peripheral blood, and absent megakaryocytes with normal other lineages in bone marrow.

Clinical Features & Lab Findings

• Neonatal: petechiae, purpura, mucosal bleeding
• Later: anemia, recurrent infections, pancytopenia
• Peripheral blood: isolated thrombocytopenia; normal RBC/WBC initially
• Bone marrow: absent megakaryocytes; normal other lineages

Source: CAMT Overview

This table compares CAMT, ITP, and TAR based on inheritance (autosomal recessive for CAMT/TAR, acquired for ITP), megakaryocytes in bone marrow (absent in CAMT, normal/increased in ITP, hypoplastic in TAR), radial anomalies (none except bilateral absent radii in TAR), and progression (pancytopenia in CAMT, isolated/persistent thrombocytopenia in ITP/TAR). It aids in diagnosis, management, and prognosis of these thrombocytopenias.

Diagnosis, Management & Prognosis

{ "headers": [ "Feature", "CAMT", "ITP", "TAR" ], "rows": [ [ "Inheritance", "Autosomal recessive", "Acquired", "Autosomal recessive" ], [ "Megakaryocytes (BM)", "Absent", "Normal/Increased", "Hypoplastic" ], [ "Radial anomalies", "None", "None", "Bilateral absent radii" ], [ "Progression", "To pancytopenia", "Isolated thrombocytopenia", "Persistent thrombocytopenia" ] ] }

Source: CAMT Presentation