Myotonic dystrophy type 1 (DM1) is caused by CTG repeat expansion in the DMPK gene in chromosome 19q13.3. External ophthalmoplegia is a rare manifestation in DM1. We report a DM1 patient confirmed by the presence of 650 CTG triplet expansions in the DMPK gene and had limitation of adduction gaze bilaterally. Brain MRI showed bilateral medial rectus muscles atrophy. Our patient provides additional evidence of ocular motor muscle involvement in DM1.

中文翻译：

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1型强直性肌营养不良患者的双侧内收性麻痹。

1型强直性肌营养不良症（DM1）是由19q13.3号染色体DMPK基因中的CTG重复扩增引起的。外眼肌麻痹是DM1中的罕见表现。我们报告的DM1患者被DMPK基因中650 CTG三联体扩增的存在所证实，并且双侧内收凝视受限。脑MRI显示双侧内侧直肌肌肉萎缩。我们的患者提供了眼运动肌参与DM1的其他证据。