Macrothrombocytopenia is associated with pathogenic variants in genes that regulate actin dynamics, such as Aip1/Wdr1, which are partners of cofilin7, ACTN1 and FLNA (encode actin-crosslinking protein, actinin-1 and Filamin A, respectively)8,9 and DIAPH1 (encode actin nucleation and polymerization)10. The gene discussed is WDR1; the disease is Macrothrombocytopenia.