[MIM 601 399, 616 216]

Rare. Autosomal dominant  transmission. The 2, 5 and RUNX1 types are associated with a predisposition to hemopathies (acute lympho- or myeloblastic leukemias).

Different types are distinguished:

• familial thrombocytopenia by mutation in the RUNX1 gene (or AML1, or CBFA2 in 21q22.12): moderate thrombocytopenia (30,000 to 150,000/ml) with normal-looking platelets but which may be associated with an aspirin-like syndrome  (see this term) with thrombopathy.
• familial thrombocytopenia type 2 by mutation in the ankyrin gene 26 (ANKRD26 in 10p12) [MIM 188,000]: thrombocytopenia (30,000 to 80,000/ml) that normalizes in case of infection and is associated with a low hemorrhagic risk. High plasma thrombopoïetin.
• familial thrombocytopenia type 4 by mutation in the gene CYCS (7p15) [MIM 612 004]
• familial thrombocytopenia type 5 by mutation in the ETV6 gene (12p13.2): moderate thrombocytopenia with low hemorrhagic risk
• familial thrombocytopenia type 6 by mutation in the CRS gene (20q12)
• familial thrombocytopenia type 7 by mutation in the gene IKZF5 (10q26)

There are also:

• an autosomal recessive form: familial thrombocytopenia type 3 by mutation in the FYB1 gene  (5p13) [MIM 273,900]
• an X-linked form: isolated microplatelet type 1 thrombocytopenia  without eczema nor immune deficiency caused by other mutations in the WAS gene [MIM 313 900] than Wiskott-Aldrich syndrome (see this term).

Anesthetic implications: 

total blood count; blood platelets transfusion if bleeding, avoid NSAID's.

References : 

-        Boutroux H, Favier R, Héritier S, Lapillone H, Ballerini P, Leverger G.
Mise au point : les thrombopénies constitutionnelles.
J Pediatrie et Puériculture 2018 ; 31 : 160-7.

Updated: December 2020