Emery-Dreifuss muscular dystrophy (EDMD) is a rare, a genetic disorder which presents slowly progressive skeletal muscle weakness. Most EDMD is inherited as an X- linked, and rarely inherited as an autosomal dominant (AD) disease. Mutations in six genes (EMD, LMNA, SYNE1, SYNE2, FHL1 and TMEM43) are associated with the EDMD.
We report a patient who showed AD inheritance EDMD due to SYNE2 gene mutation. Interestingly, different from other muscular dystrophy, he showed neuropathic pattern in electrodiagnostic study.
Case report
55 years old male was visited to the outpatient department of rehabilitation to get a medical certificate for applying social welfare services. He was diagnosed as a progressive muscular disorder when he was 23 years old (nearly 30 years ago) in another hospital through the electrodiagnostic study. At that time, his social economic status was low and he couldn’t evaluate for his exact diagnosis. This time, he wants to know his exact diagnosis, because his only son showed progressive muscle weakness like the patients. His Next-Generation Sequencing showed that mutation of SYNE2 gene which is related to EDMD.
The patient was normal at birth and healthy until 8 years old. When he was nine, he showed waddling gait and suffered frequent ankle inversion event. When he was twenty, muscle power of lower extremities showed progressively weakness and both calf muscle start to atrophy. When he was 30 years old, both upper extremities weakness and hand intrinsic muscle atrophy was also started, and his gait function was progressively decrease and he only could indoor gait with cane. When he was 40 years old, his upper and lower muscle weakness and atrophy were aggravated, and he could not gait et al, and he had to use wheelchair for ambulation.
In the physical Examination, motor power was decreased on both upper and lower extremities, proximal weakness was predominant (shoulder and hip girdle: trace, elbow, wrist, hand, and ankle: trace to poor). He has multiple joint contractures on both hip, shoulder, ankle, and hand joints. And he showed muscle atrophy on all extremities. Deep tendon reflex showed hypoactive, and no pathologic reflex was checked.
Laboratory test showed normal CK level (102 IU/L) and cardiac markers (CK-MD, Troponin, ProBNP). Echocardiogram showed normal function, and ejection pressure of LV was 63.2%. His pulmonary function test revealed mild restrictive lung defect, and functional vital capacity was 2.41 Liter (55% of estimated level).
In his familial history, his parents were healthy but died when the patients visit our clinic, and his siblings were all healthy. His only son was affected when he was 15 years old.
Electrodiagnostic study showed generalized sensorymotor neuropathy. Motor and Sensory nerve conduction study showed delayed latency and decreased amplitude in all extremities (Fig.2). Needle EMG showed abnormal spontaneous activity and large amplitude long duration MUAP in all extremities (Fig.3) |
