Perioperative management of MYH9 hereditary macrothrombocytopenia (Fechtner syndrome).
OBJECTIVE
Hereditary thrombocytopenias characterized by mutations in the gene for non-muscle myosin heavy chain IIA (NMMHC-IIA) are known as MYH9-related hereditary macrothrombocytopenia, and include the May-Hegglin anomaly, Sebastian platelet syndrome, Fechtner syndrome, and Epstein syndrome. Despite the presence of thrombocytopenia, these patients often have only mild or non-bleeding phenotypes. A major risk for these patients can be inappropriate treatment with long-term corticosteroids or splenectomy for misdiagnosed chronic autoimmune thrombocytopenia, as well as inadequate peri- and postoperative management.


METHODS
Using the case of a 44-yr-old male with Fechtner syndrome (macrothrombocytopenia, leukocyte inclusions, sensorineural deafness, glomerulonephritis) who underwent neurosurgery for an intracerebral arteriovenous malformation, we describe current methods to diagnose hereditary MYH9-related macrothombocytopenia by analysis of the blood smear, immunofluorescence staining of the NMMHC-IIA in leucocytes, and by MYH9-gene sequencing.


RESULTS
Clusters of NMMHC-IIA in granulocytes and a R1165C mutation in the MYH9-gene in two macrothrombocytopenic family members confirmed the diagnosis of a MYH9-related disease. The patient had no bleeding diathesis by history or physical examination. Thus no perioperative prohemostatic pharmacologic therapies or transfusions were given, with only minimal bleeding observed. Postoperative antithrombotic thromboprophylaxis was not given because of anticipated enhanced risk for bleeding. However, the patient developed symptomatic pulmonary embolism on postoperative day 6, which was successfully managed with 8 months of anticoagulation.


CONCLUSIONS
MYH9-related hereditary macrothrombocytopenia does not necessarily protect against postoperative venous thromboembolism, and affected patients who do not evince bleeding diathesis should be considered for routine postoperative pharmacologic thromboprophylaxis.
Selleng
Kathleen
K
Department of Transfusion Medicine and Immunology, Ernst-Moritz-Arndt University, Greifswald, Germany.
Lubenow
Lena E
LE
Greinacher
Andreas
A
Warkentin
Theodore E
TE
D000328:Adult; D006801:Humans; D008297:Male; D020409:Molecular Motor Proteins / Q000235:genetics*; D009154:Mutation; D018995:Myosin Heavy Chains / Q000235:genetics*; D019990:Perioperative Care; D011292:Premedication; D011655:Pulmonary Embolism / Q000188:drug therapy / Q000209:etiology; D013577:Syndrome; D013921:Thrombocytopenia / Q000188:drug therapy / Q000209:etiology*
C103814:MYH9 protein, human; D020409:Molecular Motor Proteins; D018995:Myosin Heavy Chains