RESUMO
<p><b>OBJECTIVE</b>To explore the method for early diagnosis and pathogenesis of MYH9-related syndrome through analysis of the clinical manifestation and gene mutation of a Chinese family with MYH9-related syndrome.</p><p><b>METHODS</b>Peripheral blood samples were collected from a three-generation Chinese family with MYH9-related syndrome (11 individuals, including 3 patients) and 100 healthy individuals. Polymerase chain reaction (PCR) amplification and direct sequencing of DNA were performed to analyze mutations of MYH9 gene.</p><p><b>RESULTS</b>Thrombocytopenia, increased volume of platelet, and granulocyte inclusion bodies were found in the patients with MYH9-related syndrome via a peripheral blood test. A missense mutation of a base pair (G-A) in exon 30 was revealed by PCR amplification and direct sequencing of MYH9 of the proband. That lead to Asp-Asn substitution at position 1424 (D1424N mutation). The mutation was the same as in other patients with MYH9-related syndrome. It was not found in healthy people from the Chinese family or in the other 100 healthy individuals.</p><p><b>CONCLUSIONS</b>Patients with MYH9-related syndrome show diverse symptoms. Mutation of MYH9 gene may be the molecular mechanism of MYH9-related syndrome, and D1424N mutation of MYH9 has not been reported in Chinese people. Early diagnosis of MYH9-related syndrome can be carried out by investigating family history and making early examinations.</p>