Perinatology.  2022 Mar;33(1):48-52. 10.14734/PN.2022.33.1.48.

Neonatal Thrombocytopenia due to MYH9 Missense Mutation: A Case Report

• Shin JH
• Chang My
• Lee E
• Lee YW
• Yoo JW
• Gang MH

• KMID: 2527757
• DOI: http://doi.org/10.14734/PN.2022.33.1.48

Abstract

Myosin heavy chain 9 (MYH9)-related disorders (MYH9RD) are autosomal-dominant disorders charac terized by macrothrombocytopenia with or without leukocyte inclusion bodies or extra-hematolo gical manifestations, such as sensorineural deafness, cataract, and renal impairment. MYH9RD can be misdiagnosed as an acquired form of thrombocytopenia including neonatal alloimmune thrombocy topenia and immune thrombocytopenic purpura. Here, we report the case of MYH9RD, which was misdiagnosed as alloimmune thrombocytopenia in a newborn with no extra-hematological manifestations and no familial history. Next generation sequencing of the patient revealed a missense mutation c.287C>T(p.Ser96Leu) in exon 2 of MYH9 gene. It is important to conduct a genetic test for suspected MYH9RD in infants who have a macrothrombocytopenia in a peripheral blood smear, extra-hematological manifestations, or do not respond to immunoglobulin or steroid treatment. This can prevent unnecessary tests or treatments. After diagnosis, regular follow-up for deafness, renal impairment, and cataract is required.

Keyword

MYH9-Related disorders; Thrombocytopenia; Infant; newborn