Perioperative management of a patient with May-Hegglin anomaly requiring craniotomy

Treatment of inherited thrombocytopenias

The new techniques of genetic analysis have made it possible to identify many new forms of inherited thrombocytopenias (IT) and study large series of patients. In recent years, this has changed the view of IT, highlighting the fact that, in contrast to previous belief, most patients have a modest bleeding diathesis. On the other hand, it has become evident that some of the mutations responsible for platelet deficiency predispose the patient to serious, potentially life-threatening diseases. Today's vision of IT is, therefore, very different from that of the past and the therapeutic approach must take these changes into account while also making use of the new therapies that have become available in the meantime. This review, the first devoted entirely to IT therapy, discusses how to prevent bleeding in those patients who are exposed to this risk, how to treat it if it occurs, and how to manage the serious illnesses to which patients with IT may be predisposed.

Epstein Syndrome

Epstein syndrome is characterized by sensorineural hearing impairment, macro- thrombocytopenia without neutrophil inclusion bodies, and hereditary nephritis which can progress to end-stage renal disease (ESRD) in adolescence. The prognosis of Epstein's syndrome depends on the severity of the hematological disorders and renal involvement that can lead to ESRD at an early age. Thrombocytopenia in Epstein syndrome is not an absolute contraindication for major surgical procedures like arteriovenous fistula formation or kidney transplantation. There are no set guidelines for preoperative prophylaxis in a patient with this pathology.

Spontaneous and recurrent subdural haematoma in a patient with May-Hegglin anomaly

Both acute and chronic subdural haematomas typically occur following trauma. Non-traumatic causes are less common, but aetiologies include arteriovenous malformation, intracranial aneurysm rupture, tumour-associated haemorrhage and coagulopathies. May-Hegglin anomaly is an example of a coagulopathy, which is caused by a mutation in the gene encoding non-muscle myosin heavy chain 9 (MYH9) and therefore falls into a group of diseases referred to as MYH9-related diseases (MYH9-RD). The symptomology of MYH9-RD is often mild, and patients tend to experience epistaxis, gingival bleeding and bruising. Life-threatening haemorrhage rarely occurs. In this short report, we describe a patient with known May-Hegglin anomaly who presented with a potentially life-threatening, spontaneous subdural haematoma requiring surgery on two occasions. This is only the second such report in the literature, and the first of spontaneous and recurrent haemorrhage in association with May-Hegglin anomaly.

Learning the Ropes of Platelet Count Regulation: Inherited Thrombocytopenias

Inherited thrombocytopenias (IT) are a group of hereditary disorders characterized by a reduced platelet count sometimes associated with abnormal platelet function, which can lead to bleeding but also to syndromic manifestations and predispositions to other disorders. Currently at least 41 disorders caused by mutations in 42 different genes have been described. The pathogenic mechanisms of many forms of IT have been identified as well as the gene variants implicated in megakaryocyte maturation or platelet formation and clearance, while for several of them the pathogenic mechanism is still unknown. A range of therapeutic approaches are now available to improve survival and quality of life of patients with IT; it is thus important to recognize an IT and establish a precise diagnosis. ITs may be difficult to diagnose and an initial accurate clinical evaluation is mandatory. A combination of clinical and traditional laboratory approaches together with advanced sequencing techniques provide the highest rate of diagnostic success. Despite advancement in the diagnosis of IT, around 50% of patients still do not receive a diagnosis, therefore further research in the field of ITs is warranted to further improve patient care.

Inherited thrombocytopenias: an updated guide for clinicians

The great advances in the knowledge of inherited thrombocytopenias (ITs) made since the turn of the century have significantly changed our view of these conditions. To date, ITs encompass 45 disorders with different degrees of complexity of the clinical picture and very wide variability in the prognosis. They include forms characterized by thrombocytopenia alone, forms that present with other congenital defects, and conditions that predispose to acquire additional diseases over the course of life. In this review, we recapitulate the clinical features of ITs with emphasis on the forms predisposing to additional diseases. We then discuss the key issues for a rational approach to the diagnosis of ITs in clinical practice. Finally, we aim to provide an updated and comprehensive guide to the treatment of ITs, including the management of hemostatic challenges, the treatment of severe forms, and the approach to the manifestations that add to thrombocytopenia.

Identification of a Novel MYH9 Mutation in a Young Adult With Inherited Thrombocytopenia and Recurrent Seizures by Targeted Exome Sequencing

May-Hegglin anomaly (MHA) is a rare autosomal dominant disorder caused by a mutation in the myosin heavy chain 9 (MYH9) gene. MHA patients have variable clinical manifestations including thrombocytopenia, renal injury, hearing impairment, and cataracts. We describe a 25-year-old man with isolated thrombocytopenia initially. He experienced recurrent seizures with stable thrombocytopenia after the first seizures related to intracranial hemorrhage. He was identified a novel c.3452C>T mutation by targeted exome sequencing. If a patient with thrombocytopenia shows recurrent seizures as well as renal, hearing, visual symptoms, MHA should be suspected and the targeted exome sequencing is considered an effective diagnostic tool.

Anesthetic management without perioperative platelet transfusion for cervical laminectomy and laminoplasty in a case of May-Hegglin anomaly

May-Hegglin anomaly (MHA) is an inherited autosomal dominant disorder characterized by giant platelets and inclusion bodies in granulocytes, and thrombocytopenia. There is no consensus on the perioperative management of this disorder. We report a case involving a patient with MHA who was perioperatively managed without platelet transfusion for cervical laminectomy and laminoplasty. In our case, the platelet count was measured to be 0.6 × 10⁴/µL using an automatic blood cell counter. Peripheral blood smear and genetic test analyses were performed, leading to a definitive diagnosis of MHA. However, clot retraction, serotonin release, and platelet aggregation were normal. Total intravenous anesthesia with propofol and remifentanil, in combination with intermittent injection of fentanyl, was administered. The total blood loss volume was 300 mL, and perioperative course was uneventful. Visual platelet count and platelet function were preserved in this case, although platelet or red blood cell transfusion was not performed. No bleeding tendency was observed during perioperative management.

Epidural anesthesia for labor and delivery in a patient with May-Hegglin anomaly: a case report

We report a case of May-Hegglin anomaly (MHA) in a woman who had a successful labor and delivery under epidural anesthesia. MHA is an inherited thrombocytopenia easily misdiagnosed as idiopathic (immune) thrombocytopenic purpura (ITP). Early and appropriate diagnosis of MHA during pregnancy is essential for optimal maternal and neonatal delivery outcome. Additionally, it can avoid unnecessary diagnostic studies, such as bone marrow aspiration and biopsy, and even harmful therapies with corticosteroids, immunosuppressive agents, and splenectomy. Consequently, the most serious impacts of this disease are iatrogenic managements due to misdiagnosis. It seems that in patients with MHA, adequate clinical coagulation is far more dependent on adequate platelet function than any particular platelet count. The diagnosis of MHA may pose a challenge for clinicians managing pregnant women with thrombocytopenia.

Diagnosis and treatment of inherited thrombocytopenias

Knowledge in the field of inherited thrombocytopenias (ITs) has greatly improved over the last 15 years. Several new genes responsible for thrombocytopenia have been identified leading to the definition of novel nosographic entities and to a much better characterization of the phenotypes of these diseases. To date, ITs encompass 22 disorders caused by mutations in 24 genes and characterized by different degrees of complexity and great variability in prognosis. Making a definite diagnosis is important for setting an appropriate follow-up, choosing the best treatments and providing proper counseling. Despite the abovementioned progress, diagnosis of ITs remains difficult and these disorders are still underdiagnosed. The purpose of this review is to provide an updated guide to the diagnosis of ITs based on simple procedures. Moreover, the currently available therapeutic options for these conditions are recapitulated and discussed.

MYH-9 Related Platelet Disorders: Strategies for Management and Diagnosis

MYH-9 related platelet disorders belong to the group of inherited giant platelet disorders. The MYH-9 gene encodes the non-muscular myosin heavy chain IIA (NMMHCIIA), a cytoskeletal contractile protein. Several mutations in the MYH-9 gene lead to macrothrombocytopenia, and cytoplasmic inclusion bodies within leukocytes, while the number of megakaryocytes in the bone marrow is normal. Four overlapping syndromes, known as May-Hegglin anomaly, Epstein syndrome, Fechtner syndrome and Sebastian platelet syndrome, describe different clinical manifestations of MYH9 gene mutations. Macrothrombocytopenia is present in all affected individuals, whereas only some develop additional clinical manifestations such as renal failure, hearing loss and presenile cataracts. The bleeding tendency is usually moderate, with menorrhagia and easy bruising being most frequent. The biggest risk for the individual is inappropriate treatment due to misdiagnosis of chronic autoimmune thrombocytopenia. More than 30 mutations within the 40 exons of the MYH-9 gene leading to macrothrombocytopenia have been identified, of which the upstream mutations up to amino acid ~1400 are more likely associated with syndromic manifestations than the downstream mutations. Diagnosis is based on identification of the granulocyte inclusion bodies using blood smears and immunofluorescence and is finally confirmed by identifying the mutation. Treatment is supportive and should be aimed to prevent iron deficiency anemia. Beside renal failure, the biggest risk for patients affected by a MYH-9 disorder are the adverse effects resulting form treatment based on the misdiagnosis of immune thrombocytopenia.

Epstein syndrome presenting as renal failure in young patients

Two young Chinese patients presented with renal failure and thrombocytopenia. Further investigations showed the presence of large platelets and high-frequency sensorineural hearing deficit. Genetic studies confirmed mutations in the gene encoding the myosin heavy chain (MYH-9), and Epstein Syndrome was diagnosed. One patient underwent deceased-donor kidney transplantation with satisfactory graft function. Epstein Syndrome is a rare genetic disorder with autosomal dominant inheritance. Clinicians should be aware of this entity when a young patient presents with renal failure and thrombocytopenia.

Management of bleeding and of invasive procedures in patients with platelet disorders and/or thrombocytopenia: Guidelines of the Italian Society for Haemostasis and Thrombosis (SISET)

The optimal management of bleeding or its prophylaxis in patients with disorders of platelet count or function is controversial. The bleeding diathesis of these patients is usually mild to moderate: therefore, transfusion of platelet concentrates may be inappropriate, as potential adverse effects might outweigh its benefit. The availability of several anti-hemorrhagic drugs further compounds this problem, mainly because the efficacy/suitability of the various treatment options in different clinical manifestations is not well defined. In these guidelines, promoted by the Italian Society for Studies on Haemostasis and Thrombosis (Società Italiana per lo Studio dell'Emostasi e della Trombosi [SISET]), we aim at offering the best available evidence to help the physicians involved in the management of patients with disorders of platelet count or function. Literature review and appraisal of available evidence are discussed for different clinical settings and for different available treatments, including platelet concentrates (PC), recombinant activated factor VII, desmopressin, antifibrinolytics, aprotinin and local hemostatic agents.

Anesthetic management of seven deliveries in three sisters with the May-Hegglin anomaly

May-Hegglin anomaly is a rare genetic hematological disorder characterized by thrombocytopenia, but platelet function is usually normal. Three sisters with May-Hegglin anomaly and thrombocytopenia (platelet counts 14,000-100,000/mm(3)) were given neuraxial anesthesia for a total of 7 deliveries, 5 vaginal and 2 cesarean. None of the women had complications and no blood products were transfused.

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.

CONCLUSION

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.