Novel variant in MYH9 in a child with proteinuria and thrombocytopenia: a case report and literature review

There is a lack of awareness of the diagnosis and treatment of <i>MYH9</i>-related disorder (<i>MYH9</i>-RD), which is an autosomal dominant disease with heterogeneous clinical manifestations. We summarized the clinical phenotype and reported a <i>novel</i> variant in <i>MYH9</i> in a child with focal segmental glomerulosclerosis (FSGS) and reviewed the relevant literature to better understand <i>MYH9</i>-RD. Unlike previous cases, this patient exhibited IgA deposition in the mesangial region, suggesting need for further investigation into prognostic and therapeutic significance of this finding. To reduce the risk of <i>MYH9</i>-RD misdiagnosis, we recommend assessing mean platelet diameter and granulocyte inclusions in patients with unexplained proteinuria and refractory thrombocytopenia.