A Mutation In FKTN Causes Adult Onset Of Fukuyama Congenital Muscular Dystrophy With Epilepsy And Dilated Cardiomyopathy:Phenotypic And Genetic Analysis Of A Case Report

Objective:To investigate the clinical features,imaging features and gene mutation characteristics of an adult patient with Fukuyama congenital muscular dystrophy associated with autosomal recessive FKTN gene mutation with epilepsy and dilated cardiomyopathy.Methods：Detailed neurological physical examination and auxiliary examination were performed on a male patient from an inbred family,who was admitted to Department of Neurology,The Second Affiliated Hospital of Nanchang University in July 2020,in the meanwhile,Ampliseq multiplex PCR high-throughput sequencing was used to detect the gene of the patients,and the mutation sites were verified by combining with first-generation sequencing for the patients and their family members,and the pathologies of the mutation sites were analyzed by software.Results:The patient is a 31-year-old male with no obvious abnormalities in intelligence and motor development when he was young,and poor fine motor development in the past 2 years.This time,he was admitted to the hospital for chest tightness,shortness of breath for more than 3 months,and seizures once.MRI plain scan of the head showed no obvious abnormality.Magnetic resonance imaging of the heart suggested cardiac enlargement,cardiac hypertrophy and fibrosis.The long time EEG examination showed no obvious abnormality.Serum creatine kinase(CK)was significantly elevated.No characteristic changes were detected by electromyography.The pathological examination of muscle biopsy showed chronic myopathic changes.Ampliseq multiplex PCR high-throughput sequencing analysis revealed homozygous mutation in the FKTN gene of the patient:C.1271G>A(p.G424D),which was A new mutation.Bioinformatics analysis showed that the mutation was likely pathogenic.Sanger sequencing family verification showed that both the parents and the first son of the patient had heterozygous mutation of FKTN gene C.1271G>A(p.G424D).Conclusion:FKTN mutation-associated adult-onset Fukuyama congenital muscular dystrophy can present mainly outside skeletal muscles,including dilated cardiomyopathy and epilepsy,myopathy such as muscle weakness and muscular atrophy was not obvious.Genetic testing can confirm the diagnosis,c.1271G>A is A new likely pathogenic mutation.