A 51-year-old woman with no history of purpura or mucosal bleeding, asymptomatic, who at the time of her first pregnancy at 23 years of age, had a thrombocytopenia of 35,000/uL.
She presented with normal vaginal delivery without bleeding complications.
Thrombocytopenic purpura with platelet fluctuating count (3,000 to 65,000/uL) was considered without responding to steroidal treatment or gammaglobulin.
At 50 years of age, due to prolonged metrorrhagia, hysterectomy was indicated, with a platelet count of 21,000/uL.
In April 2016, eltrombopag 50 mg/day was indicated orally, reaching a platelet count of 130,000/uL per month.
Total hysterectomy was performed in May 2016 without complications.
He became asymptomatic, but with thrombocytopenia, which in 2017 was of 3.000/uL, located in Chile University Hospital for treatment with anti-CD20 monoclonal antibody due to its character in January.
Upon admission, on February 23, 2017, a family history of thrombocytopenia was found in her two children, a sister, a cousin and several affected nephews.
The examination showed no purpura or other bleeding disorders.
The peripheral blood smear showed giant macroplates, similar to the size of a red blood cell and cytoplasmic inclusions in Döhle bodies leukocytes.
Bone marrow biopsy showed 45% cellularity with normal erythrocyte and granulocytic series and hyperlobated megakaryocytes.
Normal karyotype 46,XX.
The coagulation study showed prothrombin in 102% and TTPK in 25 seconds, normal.
The aforementioned background and the response totrombopag suggest the diagnosis of a disorder related to mutations in the MYH-9 gene.
Next Generation Sequence (Spanish Generation) gene sequencing demonstrated the pathogenic variant c.427014G>A p (A) in the MYH-9 gene.
This variant is found in exon 31 and has already been described by Kunishima et al, 20015.
We performed a study of both children with thrombocytopenia (male 27 years and female 21 years), by Sanger sequencing of exon 31, finding both variant in heterozygosis.
