PROXIMAL MYOPATHY, A PATHOGENIC VARIANT IN EXON 12 OF THE FLNC GENE

Abstract

We report the case of a 39-year-old man, who for 4 years, had severe pain in his right shoulder, with marked improvement in pain, followed by a decrease in muscle strength in the proximal part of his right upper limb. The physical examination showed mild atrophy in the deltoid and infraspinatus muscle on the right, weakness in the right upper limb. The dosages of CPK and CKMB are high; 538 and 7.13 respectively. Electroneuromyography was performed recording polyphasic potentials only in the biceps and infraspinatus muscles on the right. The gene panel for myopathy was performed, with the result: Variant c.1895C> A p. (Pro632His) in Exon 12 of the FLNC gene (NM_001458.4). Physiotherapy was indicated. Fatigue, myalgia and cramps are extremely common in myopathy, however the aforementioned case did not involve the distal muscles, but the proximal muscles. The heterozygous mutations of the FLNC gene are the cause of Distal Myopathy type 4 and, of Myofibrillar Myopathy Type 5, however the case mentioned above, showed a different pattern of muscle involvement and distinct histological changes.