Infante Jerome M, Nepomuceno Belinda Lioba
Institute for Neurosciences, Section of Neurology, St. Luke's Medical Center, Quezon City, PHL.
Cureus. 2023 Jun 27;15(6):e41025. doi: 10.7759/cureus.41025. eCollection 2023 Jun.
Oculopharyngeal muscular dystrophy (OPMD) is a late-onset myopathic genetic disorder characterized by chronic progressive dysphagia and ptosis with or without proximal limb weakness. It is most often caused by an abnormal alanine-encoding (GCN) trinucleotide repeat expansion in the first exon of the poly(A)-binding protein nuclear 1 ( gene. Patients with hypothyroidism may similarly report bilateral ptosis, dysphagia, and limb weakness. Here, we report the case of a 65-year-old Austrian female with hypothyroidism living in the Philippines who presented with gradually progressive ptosis, dysphagia, and intermittent choking episodes. No known relatives had similar symptoms. Physical examination showed bilateral symmetric ptosis, good cough reflex, and good limb muscle strength. Electromyographic studies of facial and laryngeal muscles were found to be normal. Thyroid evaluation showed biochemically hyperthyroid status while taking Levothyroxine. With a clinical suspicion for genetic progressive myopathy, we considered OPMD. Genetic testing revealed abnormal expansion of GCN trinucleotide repeats in the gene. We describe the first reported case of OPMD with detected gene expansion in the Philippines simulating hypothyroidism symptoms, suggesting possible points for misidentification and underdiagnosis of OPMD in developing countries.
眼咽型肌营养不良症(OPMD)是一种迟发性肌病性遗传疾病,其特征为慢性进行性吞咽困难和上睑下垂,伴或不伴有近端肢体无力。它最常由聚腺苷酸结合蛋白核1(PABPN1)基因第一个外显子中异常的丙氨酸编码(GCN)三核苷酸重复扩增引起。甲状腺功能减退患者可能同样会报告双侧上睑下垂、吞咽困难和肢体无力。在此,我们报告一例居住在菲律宾的65岁奥地利女性甲状腺功能减退患者,她出现逐渐进展的上睑下垂、吞咽困难和间歇性呛咳发作。没有已知亲属有类似症状。体格检查显示双侧对称性上睑下垂、良好的咳嗽反射和良好的肢体肌力。面部和喉部肌肉的肌电图检查结果正常。甲状腺评估显示在服用左甲状腺素时生化检查为甲状腺功能亢进状态。由于临床怀疑为遗传性进行性肌病,我们考虑为OPMD。基因检测显示PABPN1基因中GCN三核苷酸重复序列异常扩增。我们描述了菲律宾首例报告的检测到PABPN1基因扩增的OPMD病例,该病例模拟甲状腺功能减退症状,提示在发展中国家OPMD可能存在误诊和诊断不足的问题。