Retrospective review of medical records and mutational analysis report.

A 56-year-old woman with a history of non-ischemic cardiomyopathy was referred to the neuromuscular clinic due to paraspinal atrophy noted in lumbar MRI. She had a history of cardiac arrest at age 44, atrial fibrillation, dilated cardiomyopathy requiring pacemaker and defibrillator with latest left ventricular ejection fraction at 30-35%.  She reported progressive lower extremity weakness with difficulty climbing stairs, getting off the floor, since age 52. Examination was significant for mild neck flexor, hamstrings and hip flexor weakness (R/L) 4-/4 (MRC scale). Sensory examination and reflexes were normal. There were no contractures noted. She was unable to squat or to get out of chair without pushing off.  Lumbosacral spine MRI obtained for low back pain showed moderate to severe posterior paraspinal muscles and gluteus maximus atrophy. Cervical and thoracic spine CT showed diffuse paraspinal muscular atrophy. Creatine kinase and aldolase were normal. EMG demonstrated myopathic motor units in tensor fascia latae muscle. Genetic testing identified a heterozygous variant in the LMNA gene c.792_793ins? (p.Lys265Alafs*9), classified as pathogenic. This variant is likely the result of insertion of a mobile element into exon 4 of this gene and is expected to cause loss-of-function.

We report a novel LMNA mutation presenting diffuse paraspinal muscle atrophy, dilated cardiomyopathy and proximal lower extremity weakness. The identification of disease associated mutations and their phenotypes will be helpful in the better understating of the disease.