Nakatani Ryo, Miura Kenichiro, Shirai Yoko, Taneda Sekiko, Horinouchi Tomoko, Nozu Kandai, Honda Kazuho, Yamaguchi Yutaka, Kunishima Shinji, Hattori Motoshi
Department of Pediatric Nephrology, Tokyo Women's Medical University, Tokyo, Japan.
Department of Surgical Pathology, Tokyo Women's Medical University, Tokyo, Japan.
CEN Case Rep. 2025 Apr;14(2):141-144. doi: 10.1007/s13730-024-00922-x. Epub 2024 Aug 3.
MYH9-related disease (MYH9-RD) is characterized by congenital macrothrombocytopenia, progressive kidney failure, and sensorineural hearing loss. We describe a patient with MYH9-RD and a normal platelet count. A 13-year-old boy with a normal platelet count presented with proteinuria and hematuria and underwent a kidney biopsy. Light microscopy showed mild mesangial matrix expansion. Electron microscopy showed thinning of the glomerular basement membrane and splitting of the lamina densa. A tentative diagnosis of Alport syndrome was made. Unexpectedly, genetic analysis revealed a de novo MYH9 gene variant (p.Gln1068_Leu1074dup). A peripheral blood smear examination showed giant platelets and leukocyte inclusion bodies, confirming a diagnosis of MYH9-RD. In summary, we described a patient with MYH9-RD without thrombocytopenia who showed glomerular basement membrane abnormalities similar to Alport syndrome. Peripheral blood smear examinations may be helpful for an appropriate diagnosis of MYH9-RD, even in patients with proteinuria and a normal platelet count.
MYH9相关疾病（MYH9-RD）的特征为先天性巨血小板减少、进行性肾衰竭和感音神经性听力丧失。我们描述了一名血小板计数正常的MYH9-RD患者。一名血小板计数正常的13岁男孩出现蛋白尿和血尿，并接受了肾活检。光镜检查显示轻度系膜基质扩张。电镜检查显示肾小球基底膜变薄和致密层分裂。初步诊断为Alport综合征。出乎意料的是，基因分析发现了一个新发的MYH9基因变异（p.Gln1068_Leu1074dup）。外周血涂片检查显示巨大血小板和白细胞包涵体，确诊为MYH9-RD。总之，我们描述了一名无血小板减少的MYH9-RD患者，其表现出与Alport综合征相似的肾小球基底膜异常。即使对于蛋白尿且血小板计数正常的患者，外周血涂片检查可能有助于MYH9-RD的正确诊断。
