Adult-onset SMALED2 due to a novel BICD2 mutation presenting with asymmetrical lower limb involvement
Adult-onset SMALED2 due to a novel BICD2 mutation presenting with asymmetrical lower limb involvement
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成人发病的 SMALED2 由于新型 BICD2 突变导致不对称下肢受累
DOI：
10.5414/np301144
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发表时间：
2019-05-01
影响因子：
1.1
通讯作者：
Zhu, Min
中科院分区：
文献类型：
--
作者：
Wan, Chenyi;Wang, Yuyao;Zhu, Min
双尾D同源物2基因（BICD 2）的杂合变体与常染色体显性脊髓性肌萎缩伴下肢优势（SMALED 2）相关。这种疾病通常以先天性或早发性下肢肌无力和萎缩为特征，并伴有良性或缓慢进展。我们在此描述了一个SMALED2的常染色体显性遗传家系，受影响的个体表现为晚期成人发病的下肢肌无力和消瘦。3例患者下肢受累明显不对称。肌肉磁共振成像显示小腿中室有相当大的脂肪浸润，包括比目鱼肌和胫骨后肌。肌肉活检样本显示神经源性模式，但也观察到一些慢性肌病样特征。在BICD 2的高度保守基序中鉴定出一种新的杂合错义突变（c.361C>G）。SMALED2患者可表现为晚期成人发病和下肢不对称受累。本研究扩展了SMALED2的临床和突变谱。
Heterozygous variants in the bicaudal D homolog 2 gene (BICD2) are associated with autosomal dominant spinal muscular atrophy with lower extremity predominance (SMALED2). This disease is usually characterized by congenital or early-onset muscle weakness and atrophy of the lower extremities with benign or slow progression. We herein described an autosomal dominant inherited pedigree with SMALED2 in which the affected individuals presented with late adult-onset muscle weakness and wasting in the lower extremities. Obviously asymmetrical involvement of the lower limbs was observed in 3 individuals. Muscle magnetic resonance imaging revealed considerable fatty infiltrations in the middle compartment of the lower legs, including the soleus and tibialis posterior muscles. Muscle biopsy samples displayed a neurogenic pattern, but some chronic myopathy-like features were also observed. A novel heterozygous missense mutation (c.361C>G) was identified in a highly-conserved motif of BICD2. Patients with SMALED2 can present with late adult-onset and asymmetrical involvement of the lower limbs. The present study expands the clinical and mutational spectrum of SMALED2.