Avatrombopag improves thrombocytopenia in MYH9-related disorder following eltrombopag treatment failure

Platelets. 2022 Nov 17;33(8):1307-1311. doi: 10.1080/09537104.2022.2096211. Epub 2022 Jul 5.


MYH9-related disorder (MYH9-RD) is autosomal dominant thrombocytopenia caused by mutations in the MYH9 gene, which codes for the non-muscle myosin-IIA heavy chain. We present a case of a 24-year-old Chinese man with MYH9-RD who was initially misdiagnosed with immune thrombocytopenia. Whole-exome sequencing and Sanger sequencing revealed a novel missense mutation in the MYH9 gene at the position of c.4550 G > T (p.G1517V) in exon 32. The same phenotype was observed in the proband, his mother, and his brother, in addition to macrothrombocytopenia and Dohle-like bodies in neutrophil granulocytes without non-hematologic manifestations. Following failed treatment with eltrombopag, avatrombopag, which was not mentioned before in the MYH9-RD treatment, was administered to the patient, and thrombocytopenia improved. In this case report, we present a novel pathogenic mutation and show the potential of avatrombopag for temporarily increasing the platelet count in patients with MYH9-RD.

Keywords: Avatrombopag; MYH9-related disorder; thrombocytopenia.

Publication types

  • Case Reports

MeSH terms

  • Benzoates
  • Hearing Loss, Sensorineural* / genetics
  • Humans
  • Hydrazines
  • Male
  • Molecular Motor Proteins / genetics
  • Mutation
  • Myosin Heavy Chains / genetics
  • Pyrazoles
  • Thiazoles
  • Thiophenes
  • Thrombocytopenia* / congenital
  • Thrombocytopenia* / diagnosis
  • Thrombocytopenia* / drug therapy
  • Thrombocytopenia* / genetics
  • Treatment Failure


  • Benzoates
  • Hydrazines
  • MYH9 protein, human
  • Molecular Motor Proteins
  • Pyrazoles
  • Thiazoles
  • Thiophenes
  • avatrombopag
  • Myosin Heavy Chains
  • eltrombopag

Supplementary concepts

  • MYH9-Related Disorders