Cardiomyopathy, Proximal Myopathy, Camptocormia, and Novel Filamin C (FLNC) Variant: A Case Report.

BACKGROUND Filamin C (FLNC) is an actin crosslinking protein that provides structural support for the sarcomere. The exact function of FLNC is unknown; however, mutations have been reported in myopathies and cardiomyopathies, but rarely both. In this paper, we describe a case of adult-onset camptocormia, proximal myopathy, and cardiomyopathy and an intronic FLNC mutation. CASE REPORT A 56-year-old man was referred to the neurology clinic for truncal weakness. The patient reported having curvature of his spine, which he said his mother also had prior to her dying suddenly due to a "cardiac issue." The patient was found to have fatty infiltration of the periscapular and paraspinal muscles. Additionally, electromyography revealed irritable myopathy of the paraspinal muscles, and an echocardiogram revealed an ejection fraction of 40%. A genetic panel conducted through PerkinElmer Genomics revealed a heterozygous mutation c.1210+3A>G in the intron region of FLNC. Due to his low ejection fraction and family history of sudden cardiac death, he received an implantable cardioverter-defibrillator and began carvedilol. The patient received physical therapy for camptocormia. CONCLUSIONS The variability in genotypic-phenotypic relationships of FLNC mutations is a growing area of research. It is important to increase awareness to further the development of gene-targeted therapies. We hope this unique clinical presentation of co-occurring skeletal and cardiomyopathy secondary to an intronic mutation will increase awareness of the broad phenotypic spectrum of FLNC mutations.