Mutations in myotubularin-related protein 2 (MTMR2) were shown to underlie Charcot-Marie-Tooth type 4B1 (CMT4B1) disease, a rare autosomal recessive demyelinating neuropathy, characterized by severe early-onset motor and sensory neuropathy. We describe three siblings of consanguineous kindred presenting with hypotonia, reduced muscle tone, action tremor, dysmetria, areflexia, and skeletal deformities, consistent with a diagnosis of CMT. Whole-exome sequencing identified a novel homozygous c.336_337 insertion mutation in MTMR2, resulting in a frameshift and putative truncated protein. In this concise report, we discuss the clinical presentation of this rare disease and support the limited number of observations regarding the pathogenesis of MTMR2-related neuropathies.

中文翻译：

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新的MTMR2突变导致严重的Charcot-Marie-Tooth 4B1型疾病：一例病例报告。

肌管蛋白相关蛋白2（MTMR2）的突变被证明是Charcot-Marie-Tooth型4B1（CMT4B1）疾病的基础，Charcot-Marie-Tooth型4B1（CMT4B1）疾病是一种罕见的常染色体隐性脱髓鞘性神经病，其特征是严重的早发性运动和感觉神经病。我们描述了近亲的三个兄弟姐妹，伴有肌张力减退，肌张力降低，动作震颤，子宫发育不良，反射力减退和骨骼畸形，与CMT的诊断相符。全基因组测序鉴定了一种新的纯合c.336_337插入突变MTMR2，导致移码和截短的推定蛋白质。在这份简明的报告中，我们讨论了这种罕见疾病的临床表现，并支持有关MTMR2发病机理的有限观察结果相关的神经病。