Abstract:

McLeod syndrome is a rare neuroacanthocytosis caused by mutation of the XK gene. Acanthocytes in peripheral blood, systemic chorea, neuropathy, myopathy and increased serum levels of creatine kinase are observed in this syndrome, and mental manifestations and cardiomyopathy can also arise as complications. Various mutations in the XK gene have been reported, but the pathological condition in McLeod syndrome is unclear because of a lack of reports. We report a 64‐year‐old man with McLeod syndrome who showed increased levels of creatine kinase, and muscle atrophy and weakness in bilateral lower limbs. Peripheral blood smear showed numerous acanthocytes, and reduced levels of Kell antigen and the absence of XK protein suggested McLeod syndrome. Genetic analysis showed a mutation of c.del724_729TGTAGinsGGTCCTCTTTACC on exon 3 of the XK gene. To our knowledge, this is a novel genetic mutation in the XK gene.

日本語要旨:

McLeod syndromeはXK遺伝子変異により引き起こされる神経有棘赤血球症である。XK遺伝子の変異は数多く報告されているが、希少疾患であるMcLeod syndromeの病態はいまだにわかっていない。我々はCK値上昇と下肢の筋委縮・筋力低下を伴う64歳男性のMcLeod syndrome 患者を報告する。この患者は明らかな有棘赤血球とKell抗原の低下が見られ、XKタンパク質が欠損していた。本患者の遺伝子解析を行い、XK遺伝子のエクソン3にc.del724_729TGTAGinsGGTCCTCTTTACC の新規変異を見出した。