Renal manifestations of patients with MYH9-related disorders.

MYH9-related disorders are a group of autosomal, dominantly inherited disorders caused by mutations of the MYH9 gene, which encodes the non-muscle myosin heavy chain IIA (NMMHC-IIA). May-Hegglin anomaly and Sebastian, Fechtner, and Epstein syndromes belong to this group. Macrothrombocytopenia is a common characteristic associated with MYH9-related disorders, and basophilic cytoplasmic inclusion bodies in leukocytes (Döhle-like bodies), deafness, cataracts, and glomerulopathy are also found in some patients. In this study, renal manifestations of 7 unrelated Korean patients with MYH9-related disorders were analyzed. Of a total of 7 patients, 4 had disease-related family histories. One familial case had a mutation in the tail domain of NMMHC-IIA and showed milder renal involvement with preserved renal function by his 30s. Among the 3 familial cases without renal involvement, 2 had mutations in the tail domain of NMMHC-IIA and 1 had a mutation in the motor domain. The remaining 3 sporadic cases had severe renal involvement with rapid progression to end-stage renal disease and mutations located in the motor domain. In summary, mutations in the motor domain of NMMHC-IIA and negative family history were associated with severe renal involvement in patients with MYH9-related disorders. These results are in agreement with those of previous reports.