Successful splenectomy in May-Hegglin anomaly: report of a case with platelet kinetic studies

CKD in MYH9-related disorders

MYH9-related disorders are rare causes of chronic kidney disease (CKD) presenting as chronic glomerulonephritis and derive from mutations of the MYH9 gene, which encodes for the nonmuscle myosin heavy chain IIA. These disorders are autosomal dominant and include May-Hegglin anomaly and Sebastian, Fechtner, and Epstein syndromes. Diagnosis of these disorders is made first in early childhood because of the characteristic peripheral-blood smear findings of thrombocytopenia, giant platelets, and variably detected basophilic cytoplasmic inclusion bodies in leukocytes. CKD typically develops later in adulthood and may progress to end-stage renal disease. MYH9-related disorders may be associated with deafness and cataract; hence, Alport syndrome becomes important in the differential diagnosis. However, the autosomal dominance pattern of inheritance and characteristic peripheral-blood smear findings in the former help differentiate the two conditions. New evidence suggests that MYH9 gene alterations also are associated with a greater risk of focal segmental glomerulosclerosis and hypertensive nephrosclerosis in African Americans. The purpose of this review is to focus on the known, but rarely recognized association of MYH9-related disorders with CKD and highlight the recent discoveries related to the MYH9 gene that may explain the reason for a high CKD burden in African Americans.

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

May-Hegglin anomaly (MHA) is a rare type of autosomal dominant platelet disorder associated with mutations in the gene encoding nonmuscle myosin heavy chain 9 (MYH9). It is characterized by the presence of large platelets, leukocyte inclusions, and thrombocytopenia. The bleeding tendency is usually mild, but severe hemorrhages have been reported. This is the first reported case of a patient with MHA who underwent craniotomy for intractable seizure disorder of temporal lobe origin. Patients who have thrombocytopenia have a higher likelihood of developing intraoperative or postoperative intracranial hematoma and bleeding complications. The patient was administered desmopressin (DDAVP) prior to the neurosurgical procedure and had no complications. With this approach, the use of platelet concentrates could be avoided. We discuss the role of DDAVP in MHA and related platelet disorders and review the current literature.

Coincidental finding of May-Hegglin anomaly in a patient with end-stage renal failure

We present two cases of May-Hegglin anomaly incidentally discovered in a patient and his brother during investigation of the patient for end-stage renal failure and workup for renal transplantation. Routine laboratory tests were performed and included a basically normal clotting profile. Ultrastructural studies of the May-Hegglin inclusions proved diagnostic, findings were compared with those of two similar granulocyte inclusion bodies, and nomenclature discrepancies that still exist in most references are again emphasized. The finding of the May-Hegglin anomaly in our patient appears to be incidental to the underlying renal disease. A successful renal transplant has been carried out in this patient. We now report on a patient and his brother in which the MHA was discovered during workup of the patient for end-stage renal failure and renal transplantation. No association between the underlying renal disease and the MHA could be demonstrated.