RESUMEN
OBJECTIVE@#To identify the mutation type of non-muscle myosin heavy chain 9 (MYH9) gene and investigate the clinical features of a pedigree affected with MYH9 gene-related disease.@*METHODS@#Peripheral blood samples of the proband and his family members were collected. Routine blood tests were performed, which included platelet counting and Wright's staining to observe the granulocyte inclusions and giant platelets. PCR was used to amplify exons 2, 17, 27, 31, 39 and 41 of the MYH9 gene, and the mutation site was determined by Sanger sequencing.@*RESULTS@#All patients from the pedigree presented a typical triad of thrombocytopenia, giant platelets, and inclusion bodies in leukocytes. In addition, two patients had nephritis and cataract. All affected members carried a heterozygous missense mutation of c.5521G>A (p.glu1841Lys) in exon 39 of the MYH9 gene. The same mutation was not found among healthy members of the pedigree and the controls.@*CONCLUSION@#The c.5521G>A (p.Glu1841Lys) mutation in the MYH9 gene probably underlies the MYH9-related disease in this pedigree.