{Reference Type}: Journal Article
{Title}: A novel de novo MYH9 mutation in MYH9-related disease: A case report and review of literature.
{Author}: Ai Q;Zhao L;Yin J;Jiang L;Jin Q;Hu X;Chen S;
{Journal}: Medicine (Baltimore)
{Volume}: 99
{Issue}: 4
{Year}: Jan 2020
{Factor}: 1.817
{DOI}: 10.1097/MD.0000000000018887
{Abstract}: <B>BACKGROUND: </B>MYH9-related disease (MYH9-RD) is a rare autosomal dominant disorder caused by mutations in MYH9, which is responsible for encoding nonmuscle myosin heavy chains IIA (NMMHCIIA). MYH9-RD is clinically characterized by congenital macrothrombocytopenia, granulocyte inclusions variably associated with the risk of developing progressive sensorineural deafness, cataracts and nephropathy.<BR><B>METHODS: </B>A 5-year-old boy had a history of a mild bleeding tendency and chronic thrombocytopenia, first identified at four months of age. No other family members were noted to have similar clinical features or hematologic disorders.<BR><B>METHODS: </B>The boy was diagnosed with MYH9-RD. Light microscopic examination of peripheral blood films (Wright-Giemsa stain) showed marked platelet macrocytosis with giant platelets and basophilic Döhle-like inclusions in 83% of the neutrophils. Immunofluorescence analysis disclosed a type II pattern, manifested by neutrophils which contained several circle-to-oval shaped cytoplasmic NMMMHCA-positive granules. Sequencing analysis of MYH9-RD genes was carried out and revealed a novel missense mutation of c.97T>G (p.W33G) in the patient but not in his parents.<BR><B>METHODS: </B>No treatment is necessary. Recognition of MYH9-RD is important to Avoiding unnecessary and potentially harmful treatments.<BR><B>RESULTS: </B>The patient's condition remained stable during the follow-up.<BR><B>CONCLUSIONS: </B>As a result of identifying this missense mutation in this particular case, we have added c.97T>G (p.W33G) to the broad spectrum of potential MYH9 mutations.